Aquaculture

Mourning - Virginia Tech Tragedy

2007-04-29T13:36:00.000-07:00

I haven't posted in awhile after seeing the Virginia Tech campus tragedy.

Heard a lot of the students talking about what they would do, if they had been caught in the same situation; those in Columbine and VT. Unfortunately, nobody was communicating with or hearing from those they needed to, law enforcement to tell them what they should do.

I called our Sheriff Department, and they would have gladly sent out Sheriff Ron Hewett to answer questions for the student body, if the College requested it. I approached Campus security for that. The Chief of Campus police put together a panel of speakers from law enforcement to mental health, to address questions and concerns for students. This really needs to be going on, regularly, on every campus, workplace and organization to prevent tragedies like these we've seen in the past.

How Fish Smell and Breathe

2007-04-16T02:28:00.000-07:00

I've completed part of my term project, focusing on the "nostrils," or more properly, nares in fish. I based my findings primarily on Koi anatomy. Species vary. In species with barbel (the hair-like appendage from sides of mouth, like this koi) are also used in the detection of scent / food as well.

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Adding longer cilia. Needs some trimming.
Just completed this morning... the model is still in the process of drying.

Model based on Roles of the olfactory epithelium, glomerulus, and mitral cells-olfactory nerve in smell.

Additional images of Koi Nares

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Labels on nares (nostrils) and barbel which are also involved with scent.

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This weekend I also worked on "How Fish Breathe," and doing an overview on the gills.

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Aquaculture - Koi Diet

2007-04-15T10:00:00.000-07:00

While studying on anatomy of fish and the technical definition of "barbel" which is used for the fish sense of "smell" in location of food and whatnot, I came across this golden tidbit on another website.

The Fundamentals of Feeding Koi and Goldfish
By Stephen M. Meyer

Feeding Options
Carp and goldfish evolution has seen to it that the proper functioning of their digestive systems requires dietary variety over the long run. Monotonous diets are fine in aquaculture where fish are routinely culled out for market early in life, but ornamental pondkeeping aims for natural life spans, which places more subtle demands on fish-rearing techniques.

In this respect, no single food type, no matter how nutritious, represents an appropriate or healthy long-term diet for koi or goldfish. I doubt that any of the manufacturers of premium koi and goldfish food would claim that their products should be the exclusive diet of your fish. Therefore, you should make every effort to offer your koi and goldfish a varied diet (which does not mean different brands of pellets but rather different types of foods: vegetables, insects, etc.).

It is useful to think in terms of a base diet and a supplemental diet for your fish. The base diet provides the essential proteins, fats and most vitamins and minerals. The supplementary diet provides additional vitamins and minerals, but also other proteins and fats and, most importantly, variety.

After reading, I visted Wal-Mart and purchased some floating pellets and dehydrated "Baby Shrimp" specially formulated for Koi and Goldfish.

Southeastern Plankton Monitoring Network (SEPMN)

2007-04-13T08:53:00.000-07:00

On April 11, 2007, I gathered my first plankton sample (on my own) as instructed by NOAA's SEPMN (Southeastern Phytoplankton Monitoring Network), Jeff Paternoster. Data is collected and monitoring for toxic phytoplankton blooms along the Atlantic, and entered into the national database. It's a network of volunteers, and NOAA provides training and equipment free of cost.

The slide contained numerous organisms, which I've photographed and (slowly) placing at my page on the 4/11/2007 Phytoplankton Count. The microscope slide (provided by SEPMN) contains a vertical row A-H and a horizontal row from 1-8. Thus, I've broken down each set of photos into groups A-1, A-2, A-3... presently I've only made it to the B's.
One of the most interesting critters I ran up on so far, was this guy:

I'm waiting for a positive identification, but this critter looks like it may have broken from its chain and bears resemblance with Chaetoceros. However, it may be a single organism. At this point, I'm uncertain, and waiting for an expert to id the genus.
Jeff told me the reason these creatures have such long appendages is because it gives them size, not weight, which equates to increased bouyancy in the water. Pretty efficient...

Fish Brain

2007-04-10T11:54:00.000-07:00

Completing part one of my term project (Aquaculture Practicum)... the structure of the brain in a fish.

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Fish Brain

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Fish Brain

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Fish Brain
The model was based on UC David University, Teaching Resources Center and Right Brain - Left Brain, Optic Nerve Chiasm

Another sideline project I have going at the college, and haven't had a chance to work on or complete just yet...

Mollusk / Gastropod Project at Brunswick Community College

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Mollusk / Gastropod Project

My new aquarium
I have a couple koi in there...
One particular little fish in my aquarium has a big attitude problem (caught on video), and bossing the other smaller fish away from the food. It's even tried to run the Koi away from food.

Nitzschia sp.

2007-04-07T18:42:00.000-07:00

Nitzschia sp. I
05:10
Captured from Atlantic Ocean 4/4/07 sample. Several specimen are followed. Recorded at 100x magnification on Microscope, with additional magnification of 4-∞ using digital camera.

Nitzschia sp. II
03:36
Nitschia sp. filmed from sample taken from Atlantic Ocean on April 4, 2007, interacting with some other microorganisms; thalassion sp. and pleurosigma sp.

Images at Phytoplankton Sample, 4/07/2007

Hybrid Striped Bass - White Grub and Yellow Grub

2007-04-06T15:08:00.000-07:00

Two snail types which pose threat to hybrid striped bass culture.

While working around the ponds at BCC, I'd seen one pond where quite a number of the ram's horns snails lay along the embankment. I went back to collect some for display and identification. (I collect mollusk shells). While there, instructor John Baka informs me of a second disease aside of yellow grub (caused by Ram's Horn), it is the white grub. I collected some of the Ram's Horns snails, however unfortunately I did not obtain any live samples. Planorbis was plentiful, which I do have live samples.

John picked up a small piece of driftwood in the pond and showing the underside explained they were all snail eggs! I took the sample home with me, and took a look under the microscope.

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(Planorbis sp.) commonly called a ram's horn snail is involved in the life cycle of Yellow Grub and Physella sp. is involved in the life cycle of White Grub.

Full resolution image of snail eggs.

Yellow grub in Hybrid Striped Bass Culture.
(Clinostomum complanatum), a digenetic trematode is the most economically devastating disease & parasite problem encountered. These parasites are characterized by their life cycle... having a definitive host (birds) a first intermediate host (snails) and a second intermediate host (fish).

Full resolution image of snail eggs
Magnification 40x

Development of Methods for Controlling Parasitic Grub Infection Utilizing Intensified Tank Production and Fingerling Pond Modification in Hybrid Striped Bass Aquaculture
Summary: In 1997, an outbreak of an unidentified white grub disease caused high losses of fry and Phase-I fingerlings in a hybrid striped bass hatchery. With collaboration from North Carolina fish farmers, an examination into the identity, biology, and possible control strategies for this grub was conducted.
Partial experimental completion of the grub’s life cycle, analysis of grub DNA and historic reports of grub disease has indicated that the suspect grub is the common white grub Posthodiplostomum minimum.

Infection with this severe grub disease is attributed to exposure of very young fry with immature immune systems to massive numbers of cercariae — the piscine infective stage of the parasite — in the fry ponds.

The life cycle of P. minimum includes the great blue heron as definitive host, the snail host Physella sp. and a variety of fish hosts. The massive number of cercariae within the fry ponds can be attributed to large, uncontrolled populations of Physella sp.

if the snail population can be eliminated prior to fry production, the disease can be avoided.

It is recommended that fry ponds be used only for the production of Phase-I fingerlings. Further, when not being used for the production of Phase-I fingerlings, the ponds and any remnant pools should be kept drained, thoroughly dried, and tilled or plowed regularly. This would effectively eliminate any active or dormant snail populations and provide the hatchery with 2.5 to 3 months of grub-free fingerling production before snail and parasite populations reach a level that would be pathogenic to the young fish.
Source: NC Sea Grant
Complete Research Report in PDF Format.

Side-note.
How this snail got its spots...

Just for fun, in response to critics of Adobe Photoshop CS.

Ceratium furca - Dinoflagellate

2007-04-05T19:00:00.000-07:00

Fig. 47
Ceratium furca - Dinoflagellate
Microscope Magnification 100x with additional digital camera magnification 4-∞
More images from April 4, 2007 plankton sample.
Ceratium furca - Dinoflagellate, Video #1, captured from sample from Atlantic Ocean on April 4, 2007. Ceratium furca, a dinoflagellate from the Atlantic Ocean. Recorded at 100x magnification on Microscope, with additional magnification of 4-∞ using digital camera.

Hydrogen Sulfide Poisoning
In March 1994, St. Helena Bay on South Africa’s West Coast experienced a massive marine mortality. The event was caused by the decay of a huge red tide of non-toxic dinoflagellates (dominated by Ceratium furca and Prorocentrum micans). About 60 tons of rock lobster and 1500 tons of fish were washed ashore. The lobster and fish died from suffocation and hydrogen sulfide poisoning. Oxygen concentrations were near zero and hydrogen sulfide concentrations were in excess of 50 micromols per liter!
HARMFUL (non-toxic) BLOOMS
What are dinoflagellates? and why are they important?
Dinoflagellates are microscopic, (usually) unicellular, flagellated, often photosynthetic protists, commonly regarded as "algae" (Division Dinoflagellata). They are characterized by a transverse flagellum that encircles the body (often in a groove known as the cingulum) and a longitudinal flagellum oriented perpendicular to the transverse flagellum. This imparts a distinctive spiral to their swimming motion. Both flagella are inserted at the same point in the cell wall, by convention defining the ventral surface. This point is usually slightly depressed, and is termed the sulcus. In heterotrophic dinoflagellates (ones that eat other organisms), this is the point where a conical feeding structure, the peduncle, is projected in order to consume food. Dinoflagellates possess a unique nuclear structure at some stage of their life cycle - a dinokaryotic nucleus (as opposed to eukaryotic or prokaryotic), in which the chromosomes are perminently condensed. The cell wall of many dinoflagellates is divided into plates of cellulose ("armor") within amphiesmal vesicles, known as a theca. These plates form a distinctive geometry/topology known as tabulation, which is the main means for classification.
Both heterotrophic (eat other organisms) and autotrophic (photosynthetic) dinoflagellates are known. Some are both. They form a significant part of primary planktonic production in both oceans and lakes. Most dinoflagellates go through moderately complex life cycles involving several steps, both sexual and asexual, motile and non-motile. Some species form cysts composed of sporopollenin (an organic polymer), and preserve as fossils. Often the tabulation of the cell wall is somehow expressed in the shape and/or ornamentation of the cyst.
Producers of Toxins
Besides being important primary producers, and therefore an important part of the food chain, dinoflagellates are also known for producing nasty toxins, particularly when they occur in large numbers, called "red tides" because the cells are so abundant they make the water change colour. Besides being bad for a large range of marine life, red tides can also introduce non-fatal or fatal amounts of toxins into animals (particularly shellfish) that may be eaten by humans, who are also affected by the toxins. Many of these toxins are quite potent, and if not fatal, can still cause neurological and all sorts of other nasty effects. Add this to the rather ominous suspicion that red tides may be more common thanks to human inputs of phosphates and warmer global temperatures, and you can probably see why we have a vested interest in finding out more about them - both medical and economic.
Source: geo.ucalgary.ca

Koi - show fish

2007-04-05T17:43:00.000-07:00

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Koi, Japanese Carp, show fish (youtube upload). These were taken at the Brunswick Community College Aquaculture center, and are currently being kept in a recirculating system.

The fish are large. Though related to Goldfish, they grow up to over a ft in length. These particular fish measure over ft in length.

One student remarked today, though large enough for food-fish, Koi are more valuable alive (for show fish).

John Baka, an instructor at BCC said a couple of these large koi are carrying eggs and that's the reason for the branches floating in the pool, for the fish to lay their eggs. I presume the eggs will be attached to the branches and can be gathered for culture.

Diatoms in Atlantic Ocean

2007-04-04T17:45:00.000-07:00

Salt Water Microbes and Centric Diatom
Diatom getting kicked around revealing its three dimensional shape. Three clips of microscopic organisms, from salt water sample, East Coast, Atlantic Ocean.

All images, Salt Water Plankton
Salt Water Microbes
Microbial activity in salt water sample taken from Atlantic Ocean; North Carolina coastline. Diatom getting rolled around by zooplankton exposing its round surface, and flat shape from side.

Videos filmed using 100x magnification on microscope, and increased magnification up to 4-∞ using digital camera.

Plankton tow sample, for Southeast Phytoplankton Monitoring Network

Dissolved Oxygen Levels in Water

2007-03-30T22:14:00.000-07:00

John Baka, instructor at Brunswick Community College, Aquaculture Program, explains how to properly use a DO (Dissolved Oxygen) meter to detect oxygen levels in aquatic ecosystem / aquarium / recirculating system, etc.

Dissolved oxygen levels are crucial for water quality, the health and well-being of fish.

Two video uploads, available on youtube.

Video Upload #1, Dissolved Oxygen Levels

Video Upload #2, Dissolved Oxygen Levels

Dolphin Slaughter

2007-03-29T15:33:00.000-07:00

Here's an excerpt from an article on artificial intelligence, and includes dolphin intelligence in comparison with human.

Is Artificial Intelligence Possible?
By Tommy Connolly
By many of the physical methods of comparing intelligence, such as measuring the brain size to body size ratio, cetacean surpass non-human primates and even rival human beings. For example “dolphins have a cerebral cortex which is about 40% larger a human being. Their cortex is also stratified in much the same way as humans. The frontal lobe of dolphins is also developed to a level comparable to humans. In addition the parietal lobe of dolphins which "makes sense of the senses" is larger than the human parietal and frontal lobes combined. The similarities do not end there; most cetaceans have large and well-developed temporal lobes which contain sections equivalent to Broca's and Wernicke's areas in humans.”
Dolphins exhibit complex behaviours; they have a social hierarchy, they demonstrate the ability to learn complex tricks, when scavenging for food on the sea floor, some dolphins have been seen tearing off pieces of sponge and wrapping them around their "bottle nose" to prevent abrasions; illustrating yet another complex cognitive process thought to be limited to the great apes, they apparently communicate by emitting two very distinct kinds of acoustic signals, which we call whistles and clicks.
One example of their dissimilar brain structure and intelligence is their sleep technique. While most mammals and birds show signs of rapid REM (Rapid Eye Movement) sleep, reptiles and cold-blooded animals do not. REM sleep stimulates the brain regions used in learning and is often associated with dreaming. The fact that cold-blooded animals do not have REM sleep could be enough evidence to suggest that they are not conscious and therefore their brains can definitely be emulated. Furthermore, warm-blood creatures display signs of REM sleep, and thus dream and therefore must have some environmental awareness. However, dolphins sleep unihemispherically, they are “conscious” breathers, and if fall asleep they could drown. Evolution has solved this problem by letting one half of its brain sleep at a time. As dolphins utilise this technique, they lack REM sleep and therefore a high intelligence, perhaps consciousness, is possible that does not incorporate the transitional states mentioned earlier.
The evidence for animal consciousness is indirect. Intriguing, but more proof is required. However merely because we do not understand something does not mean that it is false - or not. Studying other animal minds is a useful comparative method and could even lead to the creation of artificial intelligence (that does not include irrelevant transitional states for an artificial entity), based on a model not as complex as our own. Still the central point being illustrated is how ignorant our understanding of the human brain, or any other brain is and how one day a concrete theory can change thanks to enlightening findings.

The Inhumanity of Japan's Dolphin Slaughter
This is a very graphic video I stumbled upon, on youtube.com, and disturbing as the footage was, I feel people need to know what's going on. Japan's food industry should be held in account for this barbaric practice. Dolphins have complex neural networks not too very different from humans and should not be treated in this inhumane way. Dolphin Slaughter, on youtube.com

Dolphins are herded into a small bay by banging on pipes which interfere with the dolphin's sonar (echolocation, hearing), confusing and frightening them.

Some dolphins are sorted and sold to aquariums while others are brutally stabbed and rounded up and dragged off to the slaughter house.

Machettis are used to cut open throats of conscious dolphins as they lay helpless on the pavement...

Blood pouring from this dolphin's throat...

Dolphin going in shock and writhing in agony...

School children who walk by in this video can see the dolphins agonizing in painful convulsions and slowly dying.

Japan's indifference to the dolphin slaughter shows it has no respect for regulations regarding international waters, which harm both the ocean and creatures that live within them.

Last year, I transferred an article to the web which was printed in the May 1911 issue of National Geographic, on the "Shore Whaling Industry by Roy Chapman Andrews, Assistant Curator of Mammals, American Museum of Natural History. A guide through the grisly slaughter of whales, an industry that flourished between the nineteenth and twentieth century.

Roy C. Andrews writes in 1911: "And what is to be the result of this wholesale slaughter? Inevitably the commercial extinction of the large whales, and that within a very few decades. In some localities this has already taken place and all the whales have been killed or driven from their feeding grounds."

Dolphins are Endangered
"Other dolphin species in different regions also need protection. The UN Environment Programme (UNEP) works with governments around the world to identify biodiversity-rich areas and designate specially protected areas for wildlife. For example, in the Caribbean and other regions, UNEP is supporting projects to protect the marine environment, making it safer for dolphins and whales.
As part of the global effort to protect the planetâs biodiversity, UNEP administers one of the world's largest conservation agreements-the Convention on International Trade in Endangered Species of Wild Fauna and Flora, known as CITES. Adopted in 1973, it became international law two years later.
More than 150 governments have ratified the treaty, which offers varying protection to more than 35,000 species of animals and plants, depending on their condition in the wild and the effect that international trade may have on them. CITES bans international commercial trade in species threatened with extinction, such as cheetahs, tigers, the great apes, many tortoises and birds of prey. It also protects other species, which are not threatened, but may be at serious risk unless international trade is strictly regulated."
- Dolphins as Endangered Species, United Nations Website

WHALES ARE DEVOTED TO THEIR CALVES
"All the large whales show great affection for their young, and the cows and calves will seldom leave each other when pursued by a ship. I remember at one time in Alaska, on board the steamship Tyce, Jr., we had sighted a female finback with a young one about 30 feet long beside her. They were not difficult to approach, and as the old whale rose to spout not five fathoms from the vessel's nose, the gunner fired, killing her almost instantly. The calf, although badly frightened, continued to swim in a circle about the ship, and finally, when its dead mother had been hoisted to the surface, the little fellow came alongside so close that I could have struck him with a stone. During the time that the carcass was being inflated and the gun reloaded, the calf was constantly within a few fathoms of the ship, swimming around and around, sometimes rubbing itself against the body of its dead mother. Finally a harpoon was sent crashing into its side, and it sank without a struggle."
- Roy Chapman Andrews, 1911

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Sample Letter to Japanese Officials, (seashepherd.org)

I am outraged by the annual brutal slaughter of dolphins and whales that takes place in Japan. The images of bloody red water clearly show the world that Japan has little respect for the state of the world’s oceans and for the conservation of the marine resources it claims to support.
Many scientific studies show that the oceans are in decline. We must take whatever actions are necessary to stop their over-exploitation and to protect the creatures that live in them. These dolphins do not belong to Japan. The status of the species of dolphins and whales that you kill are either endangered, threatened, or unknown. It is an unthinkable waste that they will likely end up as a meat product or deceptively sold as whale meat, polluted with toxic levels of mercury and cadmium, killing people that eat it. It is tragic and unacceptable that the remaining dolphins that are not killed will end up destined for death in an aquarium, water park, or "swim with dolphins" program.
In addition, the methods used to kill these animals are cruel. Corralling the dolphins into bays, then making them suffer a long and painful death by spears, hooks, and drowning is an inhumane way of fishing. This action is disgraceful and has caused much disappointment in the international community.
We demand that Japan permanently and immediately renounce and stop this slaughter. We will work diligently to bring this issue to international light until you have ceased your reprehensible violence.

Sincerely,

Spirogyra

2007-03-27T17:09:00.000-07:00

Recently, the instructors at Brunswick took myself and another student to the ponds and showed us certain common elements that are important to proper pond management and care. One of the important things I learned was about filament algae, and the threat it poses to fish.

Pond with filamentous algae, at Brunswick Community College
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Filamentous algae, at Brunswick Community College
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Filamentous algae are microscopic algae that form colonies of “filaments” — hence the name. These algae are notorious for forming the large, pillow-like mats of algae that float on the surface of ponds. Common types found in Ohio include Spirogyra and Pithophora.
Disadvantages
As in the case with planktonic algae, high levels of nutrients can cause filamentous algae abundance to explode, especially in ponds lacking other aquatic plants, becoming so abundant that severe oxygen problems can result in the pre-dawn hours during July and August. Treating a severe filamentous algae problem in summer will almost certainly cause a fish kill. Ohio State University Extension Fact Sheet A-8-01, Winter and Summer Fish Kills in Ponds, provides insight into how these types of summer kills occur.
From Benefits and Disadvantages of Aquatic Plants in Ponds, Ohio State University Extension

Algae are primitive aquatic plants that differ from other plants in that they have no true stems, leaves or roots. They have a place in the overall food chain as they convert the energy of the sun into forms that can be used as a food source for other aquatic life. Algae also help to increase dissolved oxygen in water. Algae grow in both fresh and salt water systems. There are said to be over 20,000 different named species of green algae. Algae occur in three different basic forms. These are categorised as planktonic, filamentous and macrophytic.
Worldwide, there are over 400 different species of the genus Spirogyra. Spirogyra tends to show in ponds as a tangled pond scum. It is also called “water silk”, “silk weed” and “mermaid tresses”. On sunny days, the mats of spirogyra filaments usually float on the surface of the water. They are kept afloat by tiny bubbles of oxygen arising from photosynthesis. These algal mats then sink when the sun goes down and the process reverses as photosynthesis is reduced. As a result, the strands of Spirogyra consume oxygen for cellular respiration. Carbon dioxide is then produced as a waste product. Where there are thick algal mats present, large fluctuations in the dissolved carbon dioxide and oxygen levels in the water can occur. This can lead to rapid changes in the pH of the water that in turn can cause stress and even death to other organisms, eg fish, living in the water.
Blanket Weed and other Pond Algae

Spirogyra - A Filament Algae, magnified at +/- 40x

A Desmid and Spirogyra algae found in the pond sample.

A Cladoceran found among the algae sample.

Vorticella - Protozoan Parasite

2007-03-26T19:35:00.000-07:00

One of the protozoans I recently photographed, is Vorticella.
A few evenings ago I captured multiple videos with the same organism.. heavily populated slide with these flower-like contractile stalk organisms.
http://pirx.com/droplet/gallery/vorticella.html contains a clear photograph of this organism I compared with, among others on the web.

"Vorticella is a sessile, peritrich ciliate. Disturbed contracts and myoneme becomes spring-like. The stalk is not branched. Often forms clusters, but not colonies."

I saw two of the stalks interacting to some degree, it's pretty amazing. This was one of my favorites that shows their behavior..
http://www.youtube.com/watch?v=Gn_z5uCokDI They seem to be quite aggressive. These are a parasite in prawns and crawfish, but it seems there's disagreement among culturists / researchers, if its a "most common" or "least common" parasite.

"Hall (1979) found that Corthunia sp, Epistylis sp. and Vorticella sp. were the most common peritrichous ciliates in cultured prawns. Common sites of infestation are the body, eye stalk, antenna, uropods and egg masses. Thelohania, a microsporidian, has been reported in various species of marine shrimps but rarely in freshwater prawns. Areerat (1988) reported one case of microsporidia infection in the opaque muscular tissue of Macrobrachium."
From Diseases of the Freshwater Prawn, Aquatic Animal Health Research Institute

(Our Fundamentals of Aquaculture text, was likely the source I was citing from):
"Ectocommensals are comprised of a variety of protozoan species which live on and/or attach to the surface of the body and the gills of their host. Common parasitic genera associated with crawfish and prawns include Epistylis, Zoothamnium, Lagenophrys, Corthunia and Acineta. Less common genera are Vorticella, Vaginicola and Opercularia."

Anyway.. both agree they're parasitic on prawns and crawfish.

Vorticella spewing waste or another bi-product? black dots / fluid begin spewing from it's bud? (about half-way through video).
http://youtube.com/watch?v=VSzc-Cl8M4Q

Vorticella
Vorticella makes an interesting video subject.
Video #9, Video #8, Video #7, Video #6, Video #5, Video #4, Video #3, and others on youtube.com

Fish Dissection

2007-03-26T18:35:00.000-07:00

Preliminary Student Dissection of Fish
Head and Gills -- high magnification and some microscopy of gills, and various sections from gills to head.

This is for my term project in Aquaculture Practicum. I'm closely observing details as I go through the fish and then to study about certain features and processes in fish anatomy, and last create a model/s of those important parts of a fish.

Warning: Some of the images are graphic, while others are enlightening in understanding how a fish (as a machine) works.
Some of the less graphic images are as follows:
Lens of Eyes in a Fish.

Staggered teeth growth on lower palette.

Fully expanded fish mouth.

Magnification of a Fish Gill at about +/- 100x

Teaching a man to fish...

2007-03-23T13:16:00.000-07:00

Today I visited the local fish market for "fish heads" to do part of my fish dissection project. I want to investigate how the brain of a fish works and interconnected. They were very kind and supplied me with a bag full of fish heads, on the house. *smile*

I saw they had this neat bumper plate in the window.

Yellow Perch

2007-03-21T18:32:00.000-07:00

Yellow Perch Production
Modified in parts from class notes by Dr. Doug Holland, Aquaculture Program, Brunswick Community College

Yellow perch (Perca flavescens) is a relatively new species to aquaculture. This species is widely distributed, ranging from Nova Scotia to South Carolina along the Atlantic seaboard and throughout the Great Lakes region and as far west as the Dakotas and Nebraska. Commercially, it has been cultured in the upper Midwest, and in the Eastern US from Pennsylvania to South Carolina.

The best culture method for yellow perch is widely debated. The material presented here is based on the extensive experiences of staff at Brunswick Community College and yellow perch farmers in Brunswick County, North Carolina.

Broodstock Management and Egg Collection
Eggs may be collected from the wild, but as with all cultured aquatic species, preferred stock comes from domesticated broodstock. In North Carolina, one of the best places to collect wild eggs is from the Perquimmans River, a tributary of Albemarle Sound. The NC Division of Marine Fisheries manages the waters below the old bridge in downtown Hertford, and there is a healthy commercial fyke-net fishery for yellow perch in these waters. The perch are trapped in the nets during their annual spawning runs in February and March, and fertilized egg ribbons may be easily collected from the nets where the fish spawn. Egg ribbons may also be collected in submerged vegetation along the edges of the river.

Domesticated yellow perch broodfish may be held in ponds at densities up to about 500 lbs/acre. The fish should range from ¼ lb to 1 lb+ in size, and there should be a 50/50 mix of males and females. Good egg production generally requires an annual increase in body weight of at least 50%. Broodfish that are feed-trained will grow and reproduce well on pelleted feeds containing about 40% crude protein and 10% crude fat. Yellow perch generally prefer live food and use of a forage species such as fathead minnows in brood ponds, which will likely improve egg production and success with spawning.

Spawning
Spawning in ponds begins in mid-February. It is a good idea to encourage growth of submerged aquatic vegetation around the edges of brood ponds for the perch to use as a spawning substrate. If there no submerged vegetation exists around the edges, discarded Christmas trees work for spawning substrate. A wetsuit and snorkeling mask may be necessary to recover egg masses in deeper water. Perch often spawn wherever bottom vegetation occurs, across the bottom of shallow ponds. In ponds where the entire bottom is covered with rooted submerged vegetation, only a small percentage of the egg ribbons may be recovered. Egg ribbons should be placed in a cooler full of well-oxygenated water and transported to the hatchery within thirty minutes. Eggs consume oxygen, therefore if the oxygen is depleted the eggs will die.

Fry Production
We have found that standard catfish egg baskets suspended in ordinary aluminum catfish hatching troughs work very well for yellow perch egg incubation and hatching. Instead of rotating paddles we simply place large air stones in the troughs to provide water agitation and aeration. Water from a small header pond is circulated through the troughs at about 1gpm per 100 gallons of trough capacity. During periods of very cold weather, the flow of pond water should be slowed down, and well water (66ºF in Brunswick County) may be added along with pond water or large aquarium heaters may be used to increase the temperature in the troughs. Be very careful using well water in yellow perch hatching troughs. Well water often contains hydrogen sulfide and other toxic compounds. The amount of hydrogen sulfide required to kill yellow perch eggs is barely detectable, and may not be noticeable to anybody but those with the most sensitive noses.

At water temperatures in mid-60'sºF, yellow perch eggs usually hatch in 5-7 days. Hatching time may be up to two or three weeks at colder temperatures. After the fry hatch out, they may be concentrated using light. A 100-watt incandescent "heat lamp" outfitted with a clamp and an 8" diameter reflector, works well and is available at most hardware and builder's supply stores. The light can be clamped to the side of the hatching trough. If all doors and windows in the hatchery are covered and the lights are turned off, the fry will collect under the light in a couple of hours. They are then siphoned into a five-gallon bucket and stocked into fingerling production tanks or prepared nursery ponds.

Fingerling Production in Tanks
Yellow perch fingerlings may be produced in tanks supplied with pond water containing adequate densities of wild zooplankton (a mixture of rotifers and small microcrustaceans is best). 7 days post-hatch, fry should be offered Fry Feed Kyowa B (<250 microns). This feed is available in the US through BioKyowa in Cape Girardeau, Missouri. A 500-gram packet costs about $45, but very little is required to get the fry started on an artificial diet. Once fry are feed-trained, they should be slowly changed over to a finely ground (500 microns or less) freeze-dried krill. After 3-4 weeks, slowly substitute a good quality #0 soft-moist crumble feed, with at least 45% crude protein and 20% crude fat. Rangen Feeds makes an excellent soft-moist crumble feed. After another 3-4 weeks, dry crumbles containing at least 45% crude protein and 12-16% crude fat may be substituted for the soft-moist crumbles.

Yellow perch fry held in troughs or tanks may experience problems with swim-bladder inflation, and settle on the bottom of the tank where they eventually smother and die.

Perch suffering from swim bladder inflation failure (sinkers) are reported from wild populations of Lakes Constance, Geneva, Lucerne, Sempach, and Zurich in central Europe. Sinkers were found at all 7 locations considered in a survey. Relative abundance of sinkers varied from 0.1% to 7.9% of local perch populations. Sinkers from wild populations and sinkers reared in the laboratory showed similar behaviour and malformations. Information on sinker syndrome in 26 physoclistous species is compiled. It is found to be a widespread problem in aquaculture, but is reported here for the first time from natural populations.
Springerlink, Zoologisches Museum, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland

This is often caused by an ultra-thin layer of lipid (fatty material) that forms on the surface of the water in hatching troughs as the eggs hatch out (the hatching eggs are the source of the lipids). This can be avoided by adding a tiny drop of dishwashing liquid to the surface of the water when the eggs are about to hatch. This may be repeated as necessary. The soap breaks up the surface tension of the water and allows the fry to get the "gulp of air" needed to inflate their swim bladder. Don't overdo it with the soap. It only takes a tiny drop to do the job. More than this will harm the fish.

Fingerling Production in Ponds
Most yellow perch fingerlings are produced in prepared nursery ponds. Small ponds up to three acres in size and 3-5 feet deep work best. The ponds should be drained and thoroughly dried during autumn. Spread about 300 lbs/acre of cottonseed meal over the pond bottom prior to flooding. Begin flooding the ponds 3-4 weeks before anticipated egg hatching. It takes much longer for an adequate zooplankton bloom to develop in winter than in spring or summer, when only a few days may be required to obtain adequate densities of rotifers and early instar microcrustaceans (the preferred food of newly hatched yellow perch). Begin examining the water for zooplankters after 10-14 days. If very few organisms are observed at this time, try inoculating the pond with water from another pond that contains high densities of zooplankters.

Fingerling production ponds should also be fertilized with liquid ammonium polyphosphate (10-34-0 fertilizer grade) or phosphoric acid (0-54-0 fertilizer grade) to promote the development of a phytoplankton bloom. Inorganic fertilizers generally don't work very well to promote phytoplankton blooms at the low water temperatures experienced in January. Begin adding the liquid fertilizer around mid-February at a rate of 1 gallon/acre of ammonium polyphosphate in soft-water ponds, or up to 3 gallons/acre of phosphoric acid in hard-water ponds. Don't use ammonium polyphosphate at the high rates required for hard water in yellow perch fingerling ponds. Yellow perch are very sensitive to ammonia and higher rates may be very detrimental to the fry. Repeat fertilizer application each week until a bloom appears on the pond. Fertilize as needed to maintain a Secchi disk depth of 12-18".

Stock the prepared nursery ponds with 200,000 to 500,000 fry. Lower stocking densities will result in larger fingerlings at harvest. Higher stocking densities may result in greater numbers of fingerlings, but they will be smaller at harvest. Yellow perch fingerlings may be harvested from ponds after 50-70 days. The fingerlings may be trapped with up to 40-50% success, but the remaining fish must be seined or concentrated by draining the pond into pre-constructed catch basins or kettles around the pond drains. Be very careful handling the fish and plan to harvest on cool days.

Yellow perch fingerlings produced in ponds must be feed-trained. Harvested fingerlings should be placed in raceways or tanks with flowing water and good aeration at a rate of 35-40 lbs per 1000 gallons of water. Following stocking of the fingerlings, the water in the tanks or raceways should be stopped and treated with oxytetracycline at a rate of 100g active ingredient per 1000 gallons of water to prevent fin rot. This bacterial disease will kill 30-40% or more of the fingerlings if this is not done.
Begin offering the perch finely ground freeze-dried krill at a rate of 5% of body weight per day. Once the perch are actively feeding, slowly switch the diet over to a #0 soft-moist crumble containing 45% crude protein and 20% crude fat. After about two weeks, dry crumbles should be substituted for the soft-moist feed. Yellow perch are not completely feed-trained until they have been taking artificial feed for 3-4 weeks. By this time, fish that are not feed- trained will starve to death and may be cannibalized by the other fish.

At this stage of their lives, yellow perch will consume up to 15% of their body weight each day. If they are not fed to satiation, they will cannibalize their siblings, and large losses (as much as 50-75%) have been attributed to this.

Frequent grading may also reduce cannibalism. Be careful not to grade the fish too frequently. Excessive handling may stress the fish and cause an outbreak of fin rot or other bacterial diseases. Yellow perch should not be handled at all at temperatures above 26ºC.

Fin rot
Fin rot in perch is generally related to stressful handling and/or severe water quality stress during harvesting. With mild cases can be treatment in a salt bath of 5 ppt will assist the fish in fighting the infection. Severe cases should be quarantined where possible and a veterinarian called to prescribe registered chemicals.
The tolerance for perch with fin rot for live or whole fresh chilled is:
• Minor cases: 5%
Major cases: nil - Fish should be processed for the fillet market.
From Size Gradings, on Fin Rot

Grow-Out to Market Size
There are many opinions among both producers and researchers about how best to produce market-size yellow perch. The market size for yellow perch is quite small compared with other cultured species, ranging from about ¼ pound (115 grams) up to about 1/3 pound (150 grams). Canadian markets will take some yellow perch that are both larger and smaller than this, but 115-150 grams is the preferred range in most markets. At Brunswick Community College and at yellow perch farms in Brunswick County, we have attempted to grow yellow perch to market size in a variety of ways. We have grown perch in open ponds, and in cages placed in ponds. We have successfully produced market-size perch in indoor recirculating systems, and in "outdoor recirculating systems", which utilize tanks supplied with water that is recirculated through ponds which function in particulate removal and biofiltration.

Pond Culture: This has proven to be a rather unreliable way to grow yellow perch to market size. We have tried many different stocking regimes, and have generally found that perch feed poorly, grow slowly (and with great variability in growth rates), and cannibalize each other heavily in open pond culture. When 1-2" feed-trained fingerlings are stocked into ponds, it generally takes 18-24 months to produce market-size fish, and a large number of the harvested fish will be outside the optimum range of size for foodfish markets. There is also low survival (40-60%) due mainly, we believe, to cannibalism. It also appears that pond-reared fish generally have a lower dressing percentage (41-45%) compared with tank-reared fish (45-51%). Total production in ponds ranges from 500 to 2500 lbs/acre per production cycle. This translates to an average production of 700-1000 lbs/acre per year, which is probably not a profitable production rate under most circumstances.

Cage Culture: Yellow perch feed and grow well in cages, as long as water quality is maintained at high levels. Yellow perch are very sensitive to ammonia. When cages are placed in shallow water, fecal material and uneaten feed tend to build up beneath the cage and cause localized problems with high ammonia concentrations in the waters around the cages. For this reason, cages should be placed in deep water (at least twice the depth of the cage) or the cages should be designed so that they can be easily moved. Aeration should be available at all times to maintain water quality around the cages. Large fingerlings (at least 4") must be stocked into cages. Smaller fingerlings necessitate the use of small mesh sizes for cage materials. Small mesh cages do not provide adequate water circulation, and may become completely clogged with algae and debris.

Indoor Recirculating Systems: This has become the most popular method for producing market-size yellow perch. Most market-size perch are produced in the upper Mid-Atlantic and upper Midwest states, where winter temperatures are cold enough to dramatically slow growth rates. Perch are maintained on feed and actively grow year-round in indoor climate-controlled recirculating production systems. They are routinely stocked in these systems at densities up to four fish per gallon, with production of up to 0.5 lb per gallon of tank capacity. Perch may be stocked in these systems at any size, but many producers prefer large stockers, in the range of 3-5". These fish are very expensive, on the order of $0.20 to $0.35 per fingerling (at an average cost of $0.07 per inch for feed-trained fingerlings). There is no reason perch cannot be stocked at smaller sizes, around 1-2", which would cost about $0.07-0.14 per fish. Since it takes 3-4 fish to weigh one pound at harvest, this would provide considerable savings to the producer. Also, yellow perch are prone to significant variability in growth rates, with resultant cannibalism. Cannibalism rates of up to 50% are not uncommon when fish are underfed and un-graded. Feeding to satiation and frequent grading, especially at smaller sizes, will greatly reduce problems with cannibalism. Be careful not to handle fish so frequently that they become stressed, especially at temperatures above 26ºC.

Outdoor Recirculating Systems: The use of outdoor tanks with water supplied by gravity flow from an adjacent pond has been shown to be a very cost-effective method for producing yellow perch in southeastern North Carolina. The water is returned to the pond by a low-head sewage pump. The pond also serves as a particulate settling chamber and biofilter. One example of the various systems now in place in Brunswick County is one that is able to produce at least 5000 lbs of market-size yellow perch in three 5000-gallon tanks supplied with water from a 1-acre pond. By separating solid fecal matter and uneaten feed into a separate small retention pond, we believe this system may be able to produce perch at much higher levels on a per-acre basis. Such a system is currently being planned for construction at Brunswick Community College.

The smaller sizes should be fed as often as is practical, up to three or four times each day. Fish more than 4 or 5 inches only need to be fed once or twice each day.

Rainbow Trout Culture II

2007-03-21T14:20:00.000-07:00

Rainbow Trout Culture II
Notes modified from Dr. Doug Holland, Aquaculture, Brunswick Community College.

Feeds and Feeding
Many companies manufacture high quality trout feeds. Feeds in all particle sizes are available, beginning with crumbles #00, 0, 1, 2, 3, 4 which are best suited for fry and small fingerlings. Advanced fingerlings, larger fish and broodstock should be fed floating or sinking pellets 1/16", 1/8", 3/16", etc.

Homemade diets should be avoided, especially unsterilized trash fish. The risk of disease combined with a diet that is usually nutritionally unbalanced, may result in a variety of nutritional disorders.

Feed utilization by the fish is of utmost importance.
Feed should be distributed in a manner that all fish get something to eat. To do so reduces variations in growth rate genetically inherent in fish. Such genetic predisposition are made worse by uneven distribution of feed and aggressive feeding instinct among individual fish.

Feeding can be made less efficient and/or wasted because:
1. Low temperatures
2. Excessive flow-through rates
3. Excessive water turbidity (trout feed by sight)

Automatic feeders may reduce labor costs, but also may result in poor feed conversion and/or uneven feed distribution, which contributes to higher feed cost. The cost of feed is generally higher than labor costs, therefore automatic feeders may represent a "false economy".

The best way to keep track of feed conversion is to keep accurate records of daily consumption rates and frequent sampling of fish for average size and weight. Fish sampling should be done preferably every two weeks but at least once per month.

Grow-Out Techniques
"The least-cost producer wins"
To develop a production strategy with any culture, available markets should be investigated first, then "working backwards" to determine a workable production strategy. By knowing the particular requirements of any market, the producer can develop methods to produce at the lowest unit cost.

Most consumers want an even supply of food-size fish throughout the year. Fluctuations in demand occur during certain times throughout the year:
- Thanksgiving and Christmas. Less people eat fish and seafood during the Holiday season.
- During Lent many people give up meat for religious reasons. Lent begins on Ash Wednesday the day following "Mardi Gras" and ends at Easter. The demand for fish and seafood increase during this time of year.

Fertilized eggs/embryos of trout, called "eyed trout eggs" are available from various parts of the world during most of the year.

For grow-out to market size fish, differential growth rates in fingerlings make stocking almost any size during most of the year possible. Differential growth rates during grow-out to market size further contributes to overall size variability, making market-size fish available throughout the year.

Growth rates of fish may be controlled by any combination of:
1. Genes. Natural variability exists between different strains and individuals within strains.
2. Feeding rates
3. Temperature which is not under the control of the farmer, but may be anticipated and utilized in overall production strategy.
4. Current/flow rate - swimming against rapid currents requires more energy which reduces growth rate at a constant feeding rate.
5. Grading. While it is best to have every fish growing at an optimum rate, naturally the rate will differ from individual to individual and from strain to strain. This can be used to ensure that market size fish are available at any and all times of the year.

Grading the fish
Grading should be done on a regular basis, but if done too frequently it risks increased stress and reduction in production levels.
A variety of grading methods are available. Producers should choose carefully to ensure the greatest grading efficiency with the least stress on the fish as possible.

Effluent Management
Types and amounts of allowable effluents from trout farms are governed by state and federal regulations. The most important of these is the NPDES permit, National Pollutant Discharge Elimination System. An NPDES permit is required of trout farms that produce more than 30,000 lbs annually.

Trout streams and other coldwater receiving waters are likely to be more profoundly affected by effluents than warmer waters, due to the low natural nutrient levels of most coldwater streams.

Suspended solids are the most serious effluent problem:
1. Contribute to Biochemical Oxygen Demand (BOD).
2. Can completely cover the bottom of receiving streams.

Settleable Solids = Suspended solids that settle out of standing water in one hour.

0.3 lb. of settleable solids are produced for every lb of feed offered to the fish in trout raceways.

Settleable solids are typically removed from effluents through the use of sedimentation basins.

Total pollutants in trout farm effluents come from many sources, but most originate from feed offered to the fish.

Levels of effluent pollutants due to feed can be calculated using the equation:

Average ppm pollutant = Pollutant Factor x Lbs Feed
Water Flow (gpm)

Pollutant factors for this equation:

Total ammonia 2.67
Nitrate 7.25
Phosphate 0.417
Settleable solids 25.0
BOD 28.3

Example
250 lbs of feed are offered each day in a hatchery with 1,000 gpm of water flow. What is the concentration in ppm of settleable solids in the effluent?

25.0 x 250
------------- = 6.25 ppm
1,000

An example of a sedimentation basin design from arizona.edu on Filtration and Biofiltration
Sedimentation basin design: Wide inlet (to reduce velocity), a surface area of .7 to 1.4 sq. ft. of basin per gpm flow (for feces with a specific gravity of 1.01 or greater), wide outlet weir (never a stand pipe), no baffles (which increase velocities) and a simple waste drain. A depth of just a few inches is enough for most designs.
Source: University of Arizona
Sedimentation Basins
These are usually tanks, ponds, lagoons, etc. which serve the purpose of slowing velocity of the water, and allow suspended solids to settle to the bottom.

Four factors taken into account for design of sedimentation basins:
1. Retention time
2. Density of waste solids
3. Water velocity and flow distribution
4. Water depth

Retention time = average period that a unit of water remains in the basin.

Retention time ranges from 15 minutes to 2 hours. For a given rate of flow, retention time increases with area and depth of the basin.

If not carefully engineered, a sedimentation basin will have an area of rapid flow down the middle, with backwater "dead zones" where water stagnates and is replaced very slowly. A system of baffles should be incorporated into the design to ensure even flow through the basin.

The basin should be about 1.5 feet deep. A shallower basin promotes scouring of the bottom, keeping solids suspended throughout the basin. There may not be enough time for solids to settle out completely in a deeper basin.

There are several types of sedimentation basins:

1. Linear clarifier - a modified concrete raceway.

Water should enter the raceway through a series of screens to distribute flow and reduce turbulence.

2. Lagoons - usually a shallow earthen pond.

The larger the pond, the more effluent it can accommodate.

3. Commercial Settling Systems

There are many types and designs of these systems available. They all generally incorporate baffles and settling tubes. This type requires less space and retention time than linear clarifiers or lagoons. They are expensive, and usually impractical in commercial aquaculture.

Solid Waste Disposal
Over half of all nutrients released by trout farms are in the form of settleable solids. The sludge from sedimentation basins is a high quality organic fertilizer. It may be composted and made available to organic farmers, gardeners, etc. It may be possible to market such material to help offset costs of waste management.

Amoeba and Amoeba Cysts

2007-03-20T23:12:00.000-07:00

The amoeba doesn't appear very active in Amoeba Video #1. But in Amoeba video #2 the activity is clear. (In the second clip I got close up to one section of the amoeba and the cytoplasm is actively moving inside. The amoeba pulls itself back into a more oval shape by end of clip.) In Amoeba Video #3, the amoeba has its cytoplasm spread out in several directions, and with close attention, its possible to see the cytoplasm moving and the amoeba slowly stretching outward. In Amoeba Video #4, the amoeba sits still most of the time, then begins stretching outward fairly quickly at the bottom left. In Amoeba Video #5, I got close up to one of the sections and focused in on the active cytoplasm. Amoeba video #6 contains sections of Amoeba's outspread proto-cytoplasmidical appendages and observing the rapid activity thats taking place inside the cytoplasm. Amoeba Video #7 focuses on one section of the amoeba, and the activity within the cytoplasm. On Amoeba Video #8, I was using the 100x magnification and camera zoom on section of the amoeba, fine focused and increased light where activity in the cytoplasm becomes very clear.

Amoeba
Enlarge to full scale
Paramecium Video #10... found another paramecium of interest to capture, although it wasn't like there's not a shortage of them on every slide. Though its not the best lighting on this one, never hurts to see the organism in realtime and in its natural habitat and going about normal activities. Here's Paramecium #11 scooting along doing its thing in its natural habitat... long and slinky.

Amoeba Cyst Video #1 ... Some amoebas are characterized by shells or tests which enclose the protoplasm (this one is classed among Protozoans in the subclass Testacealobios of the Rhizopoda). See Amoeba Cysts for more information. They measure 5 - 250 µm in size. These organisms are abundant in damp soil and amoeba-friendly watery environments. Tests are urn-shaped and some are flattened. Here's the second clip of a similar cyst I captured.

Amoeba Cyst
Enlarge to full scale

Paramecium

2007-03-18T19:31:00.000-07:00

I'm taking another blind shot at this, but this creature I've regularly seen under freshwater slides -- must be Paramecium.

Paramecium
From Aids to the Recognition of Fresh-Water Algae, Invertebrates, and Fishes

In school I was taught Paramecium had the shape of a "shoe," and this creature does at times while its on the move.

But its an oval-shaped creature, sitting still. There are many species of Paramecium, and after weeks of observing this particular creature I believe this is one of them. (Some videos vary in quality, depending on the settings).
Paramecium Video #1, Paramecium Video #2, Paramecium Video #3, Paramecium Video #4, Paramecium Video #5, Paramecium Video #6, Paramecium Video #7, Paramecium Video #8 (Not sure, but it appears it has a Cosmarium, a desmid floating along inside that it may have swallowed) and Paramecium Video #9

When I first began photographing this paramecium, I noticed it had what appeared to be a noticeably bright red-orange spot in it. Turned out, it was simply a microbe stuck to its underside and was sliding along with it. It later became detached.

To give an indication to scale, this image was taken at 40x magnification and the paramecium is in the center of the oval

Enlarge to full resolution

Protozoa, their role and impact on Aquaculture

2007-03-16T21:41:00.000-07:00

Protozoa, their role and impact on Aquaculture
Protozoa means “first animals,” and are described as unicellular (single cell, or acellular) eukaryotes [eukaryotes are distinguished from prokaryotes by the structural complexity of the cells - characterized by having many functions segregated into semi-autonomous regions of the cells (organelles), and by the cytoskeleton]. Protozoa exist either as individuals or live within a colony which comprise a significant percentage of marine plankton as a whole and may pose a threat as obligate parasites. More than 20,000 different species of Protozoa exist and are found in every conceivable niche in natural environments.

Methods of Deriving Nutrition and Reproduction
Protozoa obtain their food supply through three methods:
1. Holophytic protozoa obtain nutrients through photosynthesis.
2. Holozoic protozoa depend on plants and animals for food.
3. Saprophytic protozoa asorb organic matter through the cell wall.

Reproduction in protozoa varies. The amoeba for instance, divides into two cells through the process of fission.

(Illustration based on BBC's article on Cloning)
Other protozoa reproduce by budding, a process which consists of the cell swelling, and a bud pinches off. Spores are formed in some and repeated division may occur within a single spore.

Protozoans live at the protoplasmic level of construction. The protoplasm performs all necessary life functions in the absence of multicellular structures. The amoeba’s protoplasm is surrounded by a cell membrane. Protoplasm of the amoeba is differentiated into a nucleus which has no fixed position within surrounding cytoplasm. Amoebas feed by surrounding a food particle and engulfing it while a contractile vacuole pumps water out of the cell. Waste products are diffused from the membrane of the cell.

Protozoans are placed in one of four groups based on their mode of locomotion.
1) Pseudopodia are temporary projections of cytoplasm that allow individuals to creep.

Pseudopodia from Hunting for Hemocytes, Oysters in the Classroom, Maryland Sea Grant.

2) Flagella are whip-like filaments that lash about creating movement. Flagella may number anywhere from one to eight though usually number between one to four.

Flagella

3) Cilia are fine hair-like structures surrounding the outer membrane. Locomotion is created in a rowing-like movement by the rapid beating of cilia. Some members in this group possess cilia throughout their life cycle and are true ciliates. Others, like suctorians, have cilia during early life stages but as adults become sessile with tentacles. See this page on ciliata for examples of such species.

Cilia, from SFSU.

4) Spores are produced by sporozoan protozoa. There are no locomotive structures, and movement is achieved passively from host to host, although pseudopodia may be present in early stages. All members of this last group are parasitic.

Examples of Protozoa include both solitary and colonial organisms

Khawkinea, from Microscopy UK

Amoeba, from Microgallery, 3D

Vorticella, a colonial ciliate, from Micro Imaging, Protozoa, Vorticella

Stentor, a solitary ciliate, from Protozoa, Les Cilies

The term protozoa is a taxon of convenience, having no significance in classification schemes within the Kingdom Protista (or Protoctista) other than as a traditional functional grouping of all heterotrophic and motile species. Protozoa is comprised of a diverse assemblage of genera encompassing many unrelated groups. Modern taxonomic classification divides the kingdom Protista into 27 phyla give or take, two of which contain significant numbers of free-living, phagotrophic species.

Protozoa play an important, though often underestimated role in aquatic ecosystems. Recent studies show how abundant protozoans are in estuarine and coastal areas where they form an important connection within the microbial loop, linking bacterial and nonoplankton production to larger zooplankton and fishes. At the micro-level, grazing in the freshwater environment involves removal and consumption of material particles, organic debris and micro-organisms. This is carried out by the single-cell protozoans and multicellular biota (invertebrates). Grazing plays an important role in aquatic microbiology since it is a fundamental element in the control of microbial populations and also a major route to transfer of biomass within the food chain.
Protozoa have often been ignored in earlier studies of aquatic ecosystems, although awareness of their involvement in both pelagic (open ocean) and benthic (dwelling in the bottoms of sea or lakes) food webs has been increasing. The biology of such habitats cannot be properly described unless the protozoan community is taken into proper consideration. In pelagic commmunities, protozoa have frequently been ignored in studies focused on grazing patterns because rotifers and crustacean zooplankton take precedence in terms of population density, total biomass, productivity, rates of grazing, and nutrient regeneration. Methods of sampling protozoa differ from those required for macro-zooplankton. For instance, standard zooplankton nets are not suited for protozoa (mesh openings of 64 µ or larger) or nets which are recommended for rotifers (35 µm mesh size). As a result, information about planktonic protozoa has often been incomplete and fragmentary, with most studies limited to brief intervals in annual cycles or at particular depths and unrelated to the zooplankton community, as a whole.

Protozoa make a positive contribution because they consume organic debris, other micro-organisms in both flowing and standing water, as well as man-made aquatic systems of economic importance such as wastewater-treatment plants. Between Protozoa and multicellular grazing organisms competing for food, the relative impact of grazing by these two major groups can be considered in terms of biomass transfer and type of food supply.

Pelagic ecosystems are driven by the interaction of organisms that fall into four functional components: the autotrophic phytoplankton and the heterotrophic bacteria, protozoa and metazoa. The systematic study of the protozooplankton has traditionally lagged behind that of the other components because of their great heterogeneity, despite recognition of their important role in structuring pelgic ecosystems. The organisms representing this component are phylogenetically and functionally more diverse than either of the other components. Their study requires specialisation and dedication to specific size classes, taxonomic groupings or mineral-bearing taxa with the result that the component as a whole tends not to be regarded on an equal footing with the others of the plankton.
From Role of Protozooplankton in the Pelagic Ecosystem

At times, protozooplankton biomass may exceed that of mesozooplankton (Planktonic animals in the size range 0.2-20 mm. Examples: the copepod Calanus finmarchicus, and Rhincalanus gigas - USM Maine).
For example, flagellate protozoans are predominant predators of *picoplankton (primarily bacteria and cyanobacteria) and thus are essential components of the "microbial loop" within lakes and rivers.

* Picoplankton is a classification merely based on size: taxonomically, the group reaches across kingdoms, including bacteria (bacterioplankton), archaea, and eukaryotes. But what this group lacks in size they make up for in abundance: dip in a thimble, okay, a mini-thimble, haul in a milliliter. You'll find as many as a million organisms in surface water. Picoplankton are the most abundant living things in the world's oceans, and constitute 20-50% of marine primary productivity, making them the keystone of the oceanic food webs. Also, via photosynthesis or other chemical transformations (fixing of carbon, nitrogen, or sulfur), they have a key role in the global climate (via the carbon cycle) and the recycling of living matter in the seas.
Source: Pikoplankton, Everything2.com

Many genera consume bacteria within the surficial layer of sediments and water column while larger taxa capture and eat algae or other protozoa. They, in turn, are preyed upon by some species of oligochaetes, chironomids, and rotifers.

Finfish, Crustaceans and Mollusks
Protozoa as a predatorial parasite
Monogenea are large protozoans such as "Ich", Epistylis, Chilodonella, and copepod larvae, and can be seen in as little as 10x magnification on a standard microscope.

Epistylis
From Epistylididae, Epistylis with additional images and classification notes.

Fish inflicted with Epistylis infection
From NC Wildlife, Common Fish Diseases
"There are many factors that can cause a fish to get sick or develop sores. Fish are constantly exposed to various bacteria, fungi, viruses and parasites that occur naturally in the water. Generally the fish can deal with these with little or no problem. However, if fish are stressed or weakened by poor environmental conditions, they may not be able to fight off disease and may become sick. Some common diseases encountered in wild fish in North Carolina include white fuzzy patches on the skin caused by fungi or protozoans, red sores caused by bacteria, and black or yellow spots in the flesh of certain fish species caused by parasites. Some causes of stress include traumatic injury, spawning activity, rough handling and changes in water quality. When water temperature increases and/or fish are spawning, they are more likely to develop signs of disease. In most cases, the fish recover when conditions improve and stressors are reduced. Disease outbreaks typically don’t have a serious population level effect on natural fish populations. Usually only a small portion of a population will be seriously affected by a disease, and the population will rebound quickly."

Chilodonella
Even one parasite warrants immediate action
The parasite Chilodonella is a major threat to fish health and finding even one parasite warrants immediate treatment. Chilodonella is a potentially dangerous parasite for two reasons. First, unlike many parasites, it has a wide range of temperature tolerance and outbreaks often occur at low temperatures when fish are least able to resist. Secondly, despite is relative small size it, is potentially more dangerous than Ich, because in the initial stages there are no readily visible signs of its presence.
From Chilodonella, A dangerous parasite

Discus infested with the parasite Chilodonella, from Handbook of Fish Diseases
by Untergasser and Axelrod
"Chilodonella is a single cell microscopic parasite that attacks a fish skin and gills. The fish will rub against objects and become inactive. If the gills are affected they will stay near the water surface and gasp for air. Cloudy spots develop on the skin. The skin patches turn white and begin to disintegrate (usually over a couple day period). This opens the door to secondary infections and/or fungus. This parasite can swim and can attack other fish in the same aquarium. In aquariums with more fish, it is likely to spread rapidly. Poor water conditions also accelerate this disease. It can be introduced with live foods or from ponds or even on a plant."
From Chilodonella Parasite
In aquaculture, understanding larval stages and life cycles of parasites is necessary. To verify a diagnosis, parasites can be killed and preserved in 10% formalin and sent to a specialist.

Life cycle of Ichthyophthirius multifiliis, from University of FloridaIchthyophthirius multifiliis ("Ich" known as white spot disease) is a ciliate characterized by its relatively large size, in comparison with other protozoans.

Cause of "ick" in fish. Large macronucleus can be seen in histopath sections of fish tissues.
From Clinical Parasitology, Oklahoma State University
Ichthyophthirius multifiliis is a devastating parasite which affects channel catfish and sometimes destroys entire populations. It is not host specific and may affect a variety of cultured finfish species. It burrows under the skin of fish, causing white specks that can sometimes be seen with the unaided eye.

Image modification of Ichthyophthirius multifiliis and is characterized by its relatively large size and horseshoe-shaped nucleus (Fundamentals of Aquaculture, Avault)
After maturing, the adult parasite called a trophozoite, leaves the fish and becomes free swimming for up to 6 hours, eventually attaching to substrate.

Icthyophthirius multifiliis trophozoite from freshwater fish. Section through the surface of this ciliate, revealing the pocketed surface from which the cilia emerge. A number of basal bodies can be seen as well as numerous secretory bodies. 35,000x
From workforce.cup.edu
A membrane is secreted over the organism and cyst undergoes multiple fissions. As many as 1000 or more young, called tomites are produced. At temperature of 77 F, development into mature tomites can be completed within as little as 12 hours. When the cyst ruptures, tomites will begin the process of seeking a host, then penetrate the tissue of the fish host by cilary action and aid of an enzyme. Once penetrated, tomites mature into trophozoites and feed on the cell-tissue and fluid.

Infected with Ick
"A common sign of beginning stages of Ich infection are what is called "flashing", where fish will swipe against aquarium decorations or the gravel at the bottom of the tank in an attempt to seemingly scratch themselves. Only one or two small colonies will appear at first, and be very difficult to identify until this infection advances to near maturity." (fishtankguy.com)

More informaiton is available on Icthyophthirius multifiliis at an earlier entry on Hybrid Striped Bass Culture.

Trichodina spp. is a ciliate which occurs among virtually all species of cold and warmwater fish, and includes both fresh and saltwater fish.

Trichodina, a ciliate and parasite
Image from source in Russian language, on Parasites.
This parasite may cause extensive mortalities especially in fingerlings and is sometimes associated with poor water quality and accumulation of waste. Epizootics (meaning epidemics in animals, root origin from the Greek, "epizoon" which refers to one animal living on the surface of another) may occur throughout the year though more common in spring and fall.

"Trichodina is a surface symbiont/parasite of fish. It has a broad oral disk surrounded by membranelles and an adhesive base." From Introduction to Ciliata
Fish who are infected may begin showing white to whitish-gray blotches and copious amounts of mucus may be present, along with milky and opaque tail fins. Infected fish may congregate near incoming water and become lathargic. Heavy parasitic infestation can result in excessive mucus production which impairs respiration and results in possible suffocation, though sufficient levels of dissolved oxygen may be present in the water. Related genera affecting fish include Trichodinella and Tripartiella.

Ambiphrya
From Fish Parasite Images, images from the collection of Dr. Thomas L. Wellborn, Jr.
Ambiphrya (Scyphidia) and Apiosoma (Glossatella) are similar parasites. They are associated with high concentrations of organic matter and found attached to plants, rocks, and other substrate. They are found on all cultured warmwater fish and occasionally on salmonids, and are mostly a problem with fry and fingerlings. Infected fish may not eat and may swim lethargically near the surface. Because of hemorrhages on the gills (including possible hermorrhaging of the body) Ambiphrya causes increased sensitivity to low levels of dissolved oxygen.

Epistylis, is a stalked protozoan and has a row of cilia at the apical end used for drawing food into the main body. Under microscope the stalks contract periodically which aid in proper identification. In the western United States, Rainbow trout are common host to the Epistylis parasite, and may occasionally occur on channel catfish, and will affect other finfish species. Common symptoms in scaled fishes are erosion of skin, scales, and spines results in bloody lesions, hence the name "red sore" disease. Other symptoms include hemmorrhaging and excessive localized mucus production. Infestations in channel catfish involve spines and bones that underlie the skin on the pectoral girdle, head, and fins. Epistylis is associated with a high concentration of pollution and/or organic matter. Infection will cause infested fish to flash. Infected fish eggs may appear "fuzzy".

Chilodonella from Fish Parasite Images
Chilodonella is found on the gills and skin of finfish and distinct in parallel rows of cilia along the body margin. Chilodonella is a ciliate with a round to heart-shaped, depressed body. It is colorless and flattened, creeping rapidly across the fins, gills, and body of its host. Chilodonella is typically a coolwater parasite although one species, C. hexatichus, causes mortality at water temperatures up to 70°F.

Ichthyobodo from Fish Parasite Images
Ichthyobodo is among the smaller protozoan parasites and often overlooked because it can only be detected under high magnification. Characteristically it is tear-drop shaped and has a "fluttering" appearance, like a tree leaf in a breeze when on gills or skin of the host fish. Ichthyobodo has one pair of flagella attached to the small rounded blepharoplast (small mass of chromatin embedded in cytoplasm at base of flagellum), but two smaller flagella appear before division.
Two species of Ichthyobodo have been documented, I. necatrix and I. pyriformis. I. necatrix is the most common of the two, is widely distributed throughout the United States and is common among young trout and salmon, where it is one of the most destructive ectoparasitic (parasites that live on the exterior of another organism) protozoans. Channel catfish fry and fingerlings are especially susceptible to this parasite.

Ichthyobodo necatrix from Parasitic protozoa found on fish gills
"Ichthyobodo necator (Costia necatrix) is often found on the gills of young juveniles in the hatcheries in cases of inefficient incoming water treatment (filtration)."
I. necatrix attaches to the host body using a flat disc, extending into the host cell. Portions of the host cell are engulfed and brought into the parasite as food vacuoles ("One type of vacuole is the food vacuole, which is a temporary vacuole containing food that is obtained through phagocytosis ["cell eating"]. In addition, lysosomes recognize these food vacuoles and fuse with them for digestion of food particles. Without food vacuoles, a cell would not be able to be sufficiently nourished." From Vacuoles).
Often called the blue-slime disease, I. necatrix causes a grayish-white to bluish film to form on the skin of its prey, which comes from excess mucus production.

I. pyriformis infests gills and body and is found primarily on trout. It is pear-shaped and moves in rapid spiral pattern that is differentiated from darting movements of I. necatrix.

Dinoflagellates are identified by a groove around the middle of the cell with a flagellum lying in the groove. Oodinium sp., a well-known dinoflagellate found in fresh, brackish, and saltwater fish. Disease caused by Oodinium is often referred to as "velvet disease" since the parasite may become so abundant that a fine yellowish sheen appears.

Oodinium from Freshwater Disease and Treatment Chart
This parasite attacks the host' gills and skin and may be found attached to intestinal mucosa. The adult attaches to tissue with root-like appendages. Non-motile adults have a yellowish hue and frequently form clusters. Upon reaching maturity, they drop off and attaching themselves to a hard surface in the substrate, and begin multiplying, forming motile dinospores. Once a new host is found, their flagella disappear, and anchoring themselves to the host tissue with root-like appendages, until reaching maturity. Fish which are infested may scrape themselves showing signs of suffocation. A flashlight in a dark room may be used to inspect fish to check and see if light reflects from the Oodinium parasites.

Glenodinium from Great Lakes Water Life Photo Gallery, Algae Dinoflagellates
Glenodinium, a dinoflagellate, has been associated with mortalities in channel catfish. It is normally a free-living algal cell which may develop into heavy bloom and give water a brown hue. Cells of Glenodinium may become entrapped in lamellae of fish gills causing a proliferation of tissue.

Trichophyra
"Trichophyra piscium belongs to a Phylum of protozoan organisms all of whom possess cilia (‘hairs”) during at least one stage of their lifecycle. Most species are free-living aquatic organisms that feed on bacteria, some are commensal organisms, living on but not harming the host, and cleaning bacteria off the host’s body. Several species of Trichophyra have been identified as commensal organisms living on the gills of freshwater fishes. Large numbers of Trichophyra may cause gill irritation, or may cause the fish to secrete excessive gill mucous decreasing it’s respiratory and osmoregulatory efficiency. Some Trichophyra have been found parasitizing blood from the fish’s gills. In April 2002, 14-month old lake trout (S. namaycush) at the Maine Department of Inland Fisheries and Wildlife Enfield fish hatchery were acting as though they had gill parasites. Fish with gill parasites will rub their heads, and bodies against hard surfaces presumably to dislodge the organisms. Upon examination of the affected fish, Trichophyra piscium was identified in large numbers infesting the fish’s gills. The fish were treated as directed by MDIF&W’s fish veterinarian, and the problem was resolved."
From Protozoa: Trichophyra piscium
Trichophyra is a suctorian parasite infests gills of warmwater fish, and is distinguished by its round body and suctorial tentacles during the adult stage. It feeds on both passing protists as well as epithelial cells ('Epithelial' tissue works as a covering and lines organs in the body.) Gills may swell and become eroded, and anemia may follow. Affected fish become lethargic, may stop feeding, and may gather around inflowing water. Trichophyra populations may reach large numbers in an environment which contains high organic levels and low temperature.

Sporozoan protozoans are responsible for serious disease in fish. This class of protozoans is known by the spore morphology and by the number and location of polar capsules containing coiled filaments. Sporozoan parasites distributed in two basic groups, myxosporidians with two or more polar capsules and microsporidians with one polar capsule. Pathologists also recognize two other groups, coccidia and haemosporidea. Schäperclaus (1991), however pointed out that classification of sporozoa is difficult and that members of sporozoa have a single common feature, the formation of spores. Beyond that, classification is open to conjecture. Sporozoans tend to be host and tissue specific, having complex life cycles, and are untreatable. Life cycles of both myxosporidians and microsporidians begins at the spore level. When the host dies the spore drops to the bottom or accidentally eaten. Its polar filament(s) is used to attach to the gut wall. In miscosporidia, DNA nuclear material enters host cells through the everted polar filament. The parasite may eventually transfer to the definitive loci, or it may be carried there by the white blood cells. Once at the loci, sporozoan parasites (now termed trophozoites) divides (shizogony) and fuse (sprorogony), forming a mass of spores responsible for disease. (Fundamentals of Aquaculture, Avault)

Myxosoma cerebralis, a myxosporidian, causes "whirling disease" among salmonids, (diseased fish swim in circles). The parasite enters through any external opening, damaging the cartilage in the axial skeleton of young fish which intereferes with the function of neural structures and coordination. When fish are affected, they whirl as if chasing their tails. At one time whirling disease was the cause of catastophic losses in trout culture in central and north Europe, however today it is no longer considered a serious threat due to measures to control it. This disease has occurred in certain eastern states and Nevada.

Chain pickerel gill arch with Henneguya xenoma
When a xenoma ruptures, millions of Henneguya spores are released. The spores drift in the water and attach to a new host with a grappling hook-like organ called a polar filament. Once attached to a new host, the organism forms a new xenoma and begins to multiply. Fish veterinarians, culturists, biologists and others concerned with fish health may treat infected fish with chemotherapeutic agents or surgical removal. Unfortunately, many parasites, including Henneguya, are not easily controlled by any therapeutic procedure, thus prevention remains the best medicine. Henneguya is a fish parasite that seldom causes severe harm to the host. External examination may reveal cysts in the skin and gills; whereas, internal lesions may be found on the liver, heart, kidney, spleen or any other organ. Infections are usually not life threatening to the fish unless they impair the function of a vital organ. (From Myxosporidiosis: Henneguya sp. infestation)
Henneguya, found on freshwater finfish, is a myxosporidian having two polar capsules and a long-tail extension of each spore shell.

"Microscopic examination of the Henneguya sp. “xenomas” reveal tadpole shaped unicellular organisms with two eye-like polar capsules inside."
(From Myxosporidiosis: Henneguya sp. infestation)
Several apparent site-specific forms of Henneguya have been noted on channel catfish, on the skin and three on gill filaments. On the skin, a papillomatous form creates large lesions on body and fins, and nearly half the body may be affected. The second form creates a pustule or blister. Both forms may disfigure fish, but dressed fish show no signs of the parasite. The third form is of minor importance, occuring as a white cyst on the adipose fin of channel catfish fingerlings. On gills, an interlamellar form may cause extensive damage to channel catfish fingerlings. The second form usually has a few intralamellar cysts per filament, but does not pose a major problem. The third form produces discrete visible cysts on the gills. Henneguya has also been found in channel catfish viscera. (Fundamentals of Aquaculture, Avault).

Protozoan parasites and commensals of freshwater crawfish, prawns, and shrimp may be grouped as gregarines, microsporidians, ectocommensals, body invaders, and asptome ciliates. (Fundamentals of Aquaculture, Avault)

Gregarine protozoans, such as Nematopsis sp. have been observed in digestive tracts of shrimp in either the form of trophozoite or gametocyst. Life cycles of this parasite involve marine snails and/or clams. Trophozoites attach to the intestinal wall to asorb food, though over-all harm to the host is generally minor. Penaeid shrimp with Microspordian infestation can suffer from a chronic disease known as "cotton" or "milk" shrimp. Infestation is found throughout the musculature, depending on the species of microsporidia, or may be observed in particular tissue and organs. Microsporidians are found present in spore form with an envelope enclosing the spores in some species such as Pleistophora and Thelohania, but not all do. Nosema is one particular genus that lacks such an enclosing envelope. Infected shrimp may be active and feed normally, however microsporidians are suspect of inhibiting egg production in shrimp. Both macrobrachium and crawfish are susceptible hosts to microsporidians, though generally it is not considered a major problem in the United States. Microsporidian infection of crawfish in Europe is known as "porcelain disease". Spores are found spread throughout the musculature in heavily diseased crawfish and prawns. Research in areas of life cycles of microsporidians and their relation to crustaceans is incomplete.

"Protozoans such as Vorticella, Zoothamnium, Epistylis, Acineta and Ephelota. Affected shrimps are restless and their locomotion and respiratory functions are hampered. In heavily infected juvenile and adult shrimps, one can observe fuzzy mat-like appearance due to ciliate fouling. Maintain good water quality. Reduce organic load and silt in water exchange with good quality water."
From Protozoan Fouling, Indian Ocean.org
Ectocommensals are comprised of a variety of protozoan species which live on and/or attach to the surface of the body and the gills of their host. Common parasitic genera associated with crawfish and prawns include Epistylis, Zoothamnium, Lagenophrys, Corthunia and Acineta. Less common genera are Vorticella, Vaginicola and Opercularia.

Zoothamnium
"Zoothamnium niveum colonies on wood debris in the Indian River Lagoon. Zoothamnium niveum is a colonial Protist that reaches 2 - 3 mm in height. Individual zooids have an inverted bell shape and measure approximately 120um in height. The contractile vacuole is located below the peristomial lip. From Zoothamnium niveum, Smithsonian Institute.
"Zoothamnium prefers the gills (Johnson, 1978). Only rare incidences of heavy fouling affected the prawns adversely. Prawns have an increased oxygen demand just prior to moulting and heavy fouling can be associated with mortality due to anoxia. (Fisher, 1977)." (Fundamentals of Aquaculture, Avault)

Lagenophrys
"Lagenophrys limnoriae attached to the pleopods of Limnoria quadripunctata from the UK." From Institute of Marine Sciences, University of Portsmouth

Corthunia
"Hall (1979) found that Corthunia sp, Epistylis sp. and Vorticella sp. were the most common peritrichous ciliates in cultured prawns. Common sites of infestation are the body, eye stalk, antenna, uropods and egg masses. Thelohania, a microsporidian, has been reported in various species of marine shrimps but rarely in freshwater prawns. Areerat (1988) reported one case of microsporidia infection in the opaque muscular tissue of Macrobrachium."
From Diseases of the Freshwater Prawn, Aquatic Animal Health Research Institute

Freshwater Corthunia sp. is found on crawfish and occasionally prawns.

Acineta
"The Suctorian Acineta: feeding."
From Micrographia
Acineta sp. is commonly found in brackish water on prawns.
Epistylis, Zoothamnium and Lagenophrys are found in both fresh and brackish water on crawfish and prawns. Lagenophrys is more prevalent on prawns than crawfish.
Body invaders are protozoans that on occasion are discovered wandering about the body of their host, but if this is a case of "accidental parasitism", and whether the crustacean serves as a paratenic host, is still unclear.
Apostome ciliates (considered to be commensal) are commonly found on crawfish and prawns and have been noted infrequently in the resting stage of shrimp. Apostomes will encyst on crustaceans' exoskeleton. When crustacean molt, protozoa hatch and feed on fluids released on the shed exoskeleton. They give the appearance of tiny transparent bubbles. Following reproduction, apostomes begin the search for a host. Apostome genera commonly found in North America are Hyalophysa, Gymnodinioides and Terebrospira.

In the North American oyster culture, several serious protozoan diseases have been identified. Haplosporidium nelsoni, known as MSX before 1966, is the cause of "Delaware Bay disease" in the American oyster and likely affects other species. Oysters which are infected become emaciated and have weak shell enclosure and recession. This disease is particularly lethal for oysters, and influenced by high salinity. During dry years with high salinity (mid 60's), H. nelsoni caused high mortalities to oyster beds in Maryland, and rainy years (71-74) the disease remained confined to Mobjack Bay and the lower Chesapeake Bay. A salinity of 15 ppt or higher puts oysters at risk for the disease which may remain hidden up to 9 months. Some outbreaks encompassed mortalities up to as high as 50%-60%.
Haplosporidium costale, causes seaside disease which occurs in high salinity waters of over 25 ppt. Oysters affected by this disease characteristically fail to add new "bill" or shell, resulting in overall poor health. This disease occurs in Long Island Sound to Cape Charles and sometimes the Delaware and Chesapeake bays. H. costale has no tolerance for salinities below 25 ppt. Juveniles under two or three years may survive an outbreak, but killing up to as many as 20-50% of mature oysters. This parasite has been under study for more than thirty years because of its seriousness.
Oyster Diseases - Comparisons of Poor Health

Perkinsus marinus known as "Dermo" is common to the Gulf of Mexico and lower Chesapeake Bay and Haplosporidium nelsoni, known as MSX before 1966, is the cause of "Delaware Bay disease" in the American oyster and likely affects other species.

Images from Dermo and Oyster Research and Restoration.
The parasite invades the gut epithelium, possibly through the mantle. Once the epithelium is destroyed, the parasite is further distributed by blood throughout the remainder of the oyster. It inhibits normal gonadal development and severely emaciates affected oysters. Infections typically rise during warmer months and decline during colder months and salinities below 15 ppt, infections and resulting mortalities are thus reduced. Protozoans Marteilia refringens and Bonamia ostreae have contributed to serious problems in European waters with the oyster, Ostrea edulis.
Haplosporidian protozoans have been reported for moribund mussels in North America, but presently longterm implications remain unclear. Appearing to be an isolated event, extensive mortality of mussels on Prince Edward Island occurred because of infestation by a haplosporidian protozoan, identified as Labyrinthomyxa sp.
With increasing aquaculture of mussels (primarily Mytilus edulis), clams (various species), and scallops (several species), protozoan diseases are attracting more attention.

Reference Works Consulted and Cited
1. Fundamentals of Aquaculture, Avault
2. Ecology and Classification of North American Freshwater Invertebrates, Thorp and Covich
3. Zooplankton of the Atlantic and Gulf Coasts, A Guide to Their Identification and Ecology, Johnson and Allen
4. Freshwater Microbiology, Grazing activities in the freshwater environment: the role of protozoa and invertebrates, David C. Siege

Zooplankton and Protist Videos

2007-03-15T21:57:00.000-07:00

Tonight I got some pretty neat clips of a couple specific zooplankton I'm hoping to make positive identifications on, soon.

Species #1

Species #1

Species #1

Species #1
This creature shares similarities with other ciliate.

Example here. Ciliates include parmecium and are protozoa.

Vorticella, another ciliate, from darwin.baruch.cuny.edu
And from Phylum Cilophora, which provides a breakdown of genus and species.

From Kariorelictida: Loxodes, Photography of Ciliates
3/15/07 -- Zooplankton video on youtube.com, video one
The first in the above video, I'd already seen and photographed on several occasions. The second individual which appears, (Zooplankton Video #2) is a new one however. The algae sample I recently took from BCC has set near my bathroom window for a few days, to let the phytoplankton feast on the warm sunshine. I left it there for the past few days and didn't refrigerate. I noticed tonight's slide was full of zooplankton activity -- far more than usual, far more than phytoplankton, including some individuals I haven't seen before in rather large numbers.

Species #2
Species #2
Species #2
Species #2
Some of the strange loops and curves this little creature takes during its swim.

There was a third species
Third Video, Zooplankton and Fourth Video, Zooplankton much smaller than the previous two, which I was fortunate to keep up with briefly, with the camera. These creatures move fast, and sometimes make difficult subjects to photograph or film. Here's that cute little bug again in Video #5 zooplankton, and as its going around in circles another even smaller zooplankton swims by, but is streamlined and shares more similarity with fish.

Species #3
Here's the first species, in video one I wish to identify, caught in Zooplankton video #6.
The second species, caught in zooplankton video #7.

Video #8 Zooplankton shows one of the small zooplankton species swimming beneath what appears very likely to be a deceased ostracod of sorts (favors a small clam), you can still make out the hairs on its shell. Very brief but clear species #2, Zooplankton video #9. Species one is also captured on Zooplankton video #10.

Principle Zoological Ranks and Suffixes Where Designated

2007-03-15T21:01:00.000-07:00

Got another book in on invertebrates, and felt this would make a useful entry for future reference:


Classification in Zoology:

  Kingdom
   Phylum
    Subphylum
     Superclass
      Class
       Subclass
        Cohort
         Superorder
          Order
           Superfamily (-oidea)^a
            Family (-idae)^a
             Subfamily (-inae)
              Tribe (-ini)^a
               Subtribe (-ina)^b
                Genus
                 Subgenus
                  Species
                   Subspecies
^a An ending recommended but not mandatory
according to the International Code of Zoological
Nonmenclature.
^b An ending customary but not cited in the
code.

Approaches to Taxonomic Classification (Excerpts from pgs. 1-2)
No phylum is totally immune to an occasional reshuffling of species, renaming of constituent taxa, and recalculation of total species richness (number of species). This dynamic feature of the discipline is, in part, a necessary response to the acquisition of new knowledge, but it also results from the ubiquitous and almost inherant disagreements that usually typify groups of two or more scientists. Taxonomists are frequently labeled "splitters" or "lumpers" according to whether, respectively, they tend to acknowledge more or fewer species within an assemblage. Classifications they produce based on diverse scientific approaches, such as cladistics and numerical (=phenetics) taxonomy, can produce dramatically different views of relationships among taxa. Moreover, molecular systematics has sometimes shaken the traditional taxonomic schemes based on classical phenotype characters.

Although arguments at the species level are especially rampant, debates occasionally break out regarding the categorization of higher tiers, including classes and phyla.

Species are named today using a system of binominal nomenclature (= names composed of two parts) based on the 18th century proposal of the brilliant Swedish naturalist Carl von Linné (or Carolus Linnaeus, the latinized form he preferred to use). This is the "genus and species" designation familiar to most biology students (e.g., Homo Sapiens for the human species.) You will occasionally see a species designated with three names (a trinomen), which is permissible under guidelines of the International Code of Zoological Nomenclature. For example, Bosmina (Sinobosmina) freyi is the genus, subgenus, and species name of a water flea, or cladoceran, common in rivers (it is one of a species complex formerly called Bosmina longirostris). In contrast, Pheidole xerophila tucsonica is the genus, species, and subspecies name of a harvester ant living in the desert near Tucson, Arizona. Scientific names are either in Latin or in a form that has been latinized (e.g., B.(S.) freyi was formed by latinizing the last name of Dr. David G. Frey, to honor this now-deceased co-author of Chapter 21).

The final arbiter for naming taxa according to this system is the International Commission on Zoological Nomenclature, a judicial body elected periodically by the International Congress of Zoology to evaluate taxonomic names proposed by scientists.
Source: Ecology and Classification of North American Freshwater Invertebrates, Excerpts from Introduction, Pages 1-3
Thorp and Covich, Academic Press, 2001

Rainbow Trout Culture

2007-03-14T06:28:00.000-07:00

Feed and fingerlings make up greater than 70% of the total cost of raising trout. Assuming a sales price of $1.10 per pound, and total cost of production of $0.76, the farm nets $21,452 per year on 60,480 pounds harvested.
-NC Dept. Agriculture and Consumer Services

Modified from notes by Dr. Doug Holland, Aquaculture, Brunswick Community College on Rainbow Trout Culture I

North Carolina is the second largest producer of rainbow trout in the United States, following Idaho in production.

Aquaculture is the fastest growing segment of U.S. agriculture. The farm valueof the U.S. aquaculture industry is estimated at nearly $1 billion. Trout food fish production accounts for about 10% of the total value, and catfish for about 50% of the value. Trout farming is the oldest form of commercial fish production in the U.S.; trout have been grown in culture systems for over 150 years. Rainbow trout is the predominant species raised. Trout are cultured in earthen or concrete raceways (rectangular tanks) supplied with flowing water. In 2000, an estimated 447 trout operations harvested and sold 59 million pounds of trout valued at $64 million. Idaho produces 58% of the total dollar production. North Carolina is the second largest producer, with about 7% of the production value. In 2000, U.S. trout farmers sold 70% of their harvest to processors, 18% through recreational fee fishing operations, 5% directly to restaurants and retailers, and the remainder to other outlets. Production in the U.S. trout industry has remained stable over the last decade. Three reasons for limited expansion are: lack of suitable sites for new facilities; increasing costs associated with fish waste management; and difficulty in competingwith the retail prices of imported trout orother seafood products.
(see http://www.ncagr.com/Aquacult/Trout01.pdf)

There are about 89 farms in NC, and most of these are west of Asheville in southwestern North Carolina. The largest concentration is in Transylvania, Graham, Macon and adjacent counties.

The annual production of rainbow trout in NC varies, but lately has averaged around 7.1 million lbs, worth 1.10 per lb on average. It is obvious when looking at these figures that most of the farms in NC are small-scale family operations, each producing less than 100,000 lbs of trout each year. There are several large farms, however, and some of these are quite profitable.

Environmental Requirements
Rainbow trout is a coldwater species and requires water temps less than 68°F year-round for optimum growth. They may survive at somewhat higher temps, but with little or no growth and high stress levels.

Culture of rainbow trout in raceways requires large amounts of flow-through water. A farm with a holding capacity of 100,000 lbs of fish would require a minimum flow of 5000 gpm (gallons per minute) during the driest part of the year, assuming that it has oxygen-injection technology and a highly experienced manager. Few places have this much high-quality, cold water available year-round, even in the NC mountains. Most of the best sites in southwestern NC are already taken.

Tank and Pond Design

Major types of culture structures:
1. Ponds
2. Raceways
3. Tanks

Earthen ponds are still utilized on older farms, but are less than optimum for grow-out of food fish, though useful for fee-fishing operations. The irregular flow in current create "dead areas" which inhibit circulation of water. Difficulties in grading and sorting fish are created by slope in the side of ponds. Higher maintenance than raceways or tanks is required due to accumulation of organic matter and weed problems, etc., which are relatively economical to build, though to conserve on unit/volume, often constructed larger than they should be.

The larger the pond, the more difficult to manage. Using small, straight-sided earthen "raceways" has proven a better method and make for easier management than small round ponds. They can be lined with butyl liners to make management even easier.

"Unless your ground is a thick impervious clay, it is important to line your pond with a waterproof layer. There are several types of material on the market which you could try but most experts agree that the final choice is between relaxing beside a deluxe, butyl rubber lined pond or continuously repairing the holes in a pond lined with one of the cheaper alternatives. To protect the liner from stones you can use a layer of old carpet or sand under the butyl sheet.

If a layer of geotextile under the butyl helps protect it against stones, then another layer of geotextile, this time on top of the butyl, helps the soil to adhere to the sloping edges."
From Building a Pond - Butyl Liners

Raceways are the most widely established culture system for Rainbow Trout in both the United States and Europe. Comparing advantages with disadvantages, the disadvantages are generally outweighed.

The advantages are large densities of fish can be maintained, with few "dead" areas. Compared to ponds, differentiation in growth rate is reduced. Crowding fish for grading and harvest is much easier. A raceway can have a built in system for crowders and bar graders that are easily moved up and down the raceways, without physically removing them from the water or transferring them. Raceways may be partitioned, where several size classes of graded fish may be held simultaneously.

The disadvantages are a lack of utilization of the full water volume and abrasion. Fish tend to "school" together in 1/3 to 1/2 total volume of the raceway. Raceways are usually either poured concrete or concrete block construction. When fish are crowded to feed or grading/harvest, repeated contact with concrete walls may open them up to bacterial and fungal infections.

Round or semi-round tanks are being used by many newer farms. An advantage of round tanks is the self-cleaning aspect which takes place due to centripetal forces by the circulating water. Uneaten feed and fecal wastes are moved to the center of the tank as water moves around in circular motion. Once collected these materials are removed using a "double-drain" type system. This system reduces need for maintenance and labor costs.

Almost any tank can be used, though important it is durable, weatherproof and UV-resistant for outdoor use. It should be round or semi-round (above). This is also important in establishing a current against which the fish will swim, as is the habit of Rainbow Trout. It is important as well to obtain a tank that is already assembled or be easily assembled, and economical in cost. Tanks which are more convenient to set up and use may create an added expense, compared to cheaper tanks which will be durable though requiring more time and labor. The costs of labor and management must be compared with the cost of tanks.

Round tanks are preferred by many trout producers because the entire life cycle of the trout may be carried out in a variety of tank sizes, from broodstock to growout. There are some systems which now provide tanks that allow for fertilized eggs to be placed on top, and fry to pass through to an underlying container when hatched, which may then be removed, allowing fry to grow to fingerlings or even to market size. A major disadvantage of tank systems is the high cost, a higher initial investment is required compared to raceway systems, and comparatively, raceway systems are much more expensive to build and maintain than ponds.

Strains of Rainbow Trout
Once the culturing system has been constructed, the strain of trout must be determined.
Different strains have different characteristics that affect production and marketing:
1. DO tolerance
2. Temperature range/tolerance
3. Optimum culture densities
4. pH range/tolerance
5. Water hardness requirement
6. Growth rates under various temperature regimes.

Choosing a strain best suited to individual environmental conditions for each farm is important.

Optimum Production Level
Optimum production level for a particular system/farm may be determined by the equation:

OP = T + F + O + C

Where:

OP = optimum production level

T = ideal temperature for optimum feed conversion

F = correct amount and size of food

O = dissolved oxygen level needed to metabolize food

C = ideal flow rate for optimum exercise (swimming against the current).

Increase in temperature within the optimum range for trout production will result in increased metabolic rate, therefore feeding rate. Feeding rates should be adjusted with changes in temperature. These increases due to an increase in temperature are accompanied by an increased demand for oxygen. DO (dissolved oxygen) saturation level decreases with any increase in temperature. Due to these factors, supplemental sources of oxygen to keep DO at optimum levels, at or near saturation, are required. Aeration devices or oxygen injection may accomplish this. Oxygen injection, using pure bottled oxygen is expensive, but in many cases is economically feasible, even desirable.
Producers must be on guard not to become dependant on a pure oxygen injection system because it creates an artificially high level of production, which is unsustainable over long periods of time. Besides a risk of mechanical failure, it also creates stress to the fish due to crowding which may reduce feeding, growth rates and even potential risk of disease. An outbreak would spread rapidly and cause high mortality rate. Producers must compare risks with profit when dealing in such highly intensive production. While an oxygen injection system may look good theoretically, losing all your fish at once due to a system failure could put you out of business.

Hybrid Striped Bass

2007-03-11T16:28:00.000-07:00

From Dr. Doug Holland's notes (Brunswick Community College) on Hybrid Striped Bass, with some modifications for this blog.

Top to bottom: white bass, striped bass and hybrid striped bass (Bodie bass)
Source: NC Wildlife

Various hybrids of the striped bass have shown improvement in survival, improved growth, greater resistance to disease, and tend to be hardier under culture conditions than wild striped bass.

-The two most common crosses are:

"original cross" - striped bass (Morone saxatilis) female X white bass (Morone chrysops) male
-R.E. Stevens, SC, 1965, (Also known as the "Palmetto Bass".)

"reciprocal cross" - white bass female x striped bass male.
-Bayless, SC, 1966 (Also known as the "Sunshine Bass".)

The "original cross" remains the most popular and numerous in commercial culture. Newly hatched fry are larger and have higher survival rates in pond fingerling production than do the "reciprocal cross," therefore fingerling production is more profitable.

Hybrid striped bass are produced in all types of systems, including:

1. Open static pond culture (NC)
2. Cage culture (very limited)
3. Raceway & tank culture using flow-through water (FL, CA, MS, etc.)
4. Intensive recirculating systems (mixed results)

Hybrid fingerlings are traditionally produced in fresh water. But growout to food size is done in both fresh and brackish water, and is also possible in saltwater. Striped bass are anadromous. They spawn in freshwater and move into saltwater as adults.

"Striped bass (Morone saxitilis) are one of 7 anadromous species found in the Cape Fear River system. Due to dramatic drops in the population, a coast wide moratorium on striped bass fishing was imposed from 1985 to 1990. Although striped bass populations in other N. C. drainages have rebounded, the Cape Fear River striped bass population has not (Mallin et. al. 1998,1999,2000). Although declines in water quality and the introduction and possible predation and competition by nonnative catfishes are probably contributing to the problem, one specific culprit could be competition from hybrid striped bass. [...] Hybrid striped bass are a hybrid of striped bass (Morone saxatalis) and white bass (Morone chrysops). They have been stocked as a put and take fishery in Lake Jordon nearly every year since 1983. The hybrids are introduced to the Cape Fear River by flooding events. Through competition, hybrids utilize the resources normally available to striped bass (Patrick and Moser 2001). Hybrids do not reproduce and so the resources they keep from striped bass are not converted into reproduction. As a result of competition with hybrids, striped bass may not be as healthy and in turn, not produce as many juveniles. Tag and recapture data from studies conducted in this drainage suggested that hybrids conduct a spawning run with true striped bass as has been documented in other systems (Patrick and Moser 2001, Bishop 1967). Due to competition with true striped bass for food resources and spawning habitat, hybrid striped bass are likely having a negative impact on the striped bass population in the Cape Fear River system. Catch-per-unit-effort data showed a statistically significant drop in the fall gill net samples (Figure 32). While commercial landings of striped bass in North Carolina have shown a gradual increase since 1990. Landings in the Cape Fear System remain low and this is the only river in North Carolina that stocks hybrid striped bass. Although the hybrid striped bass population appears to be decreasing, future surveys should examine whether this trend continues."
From Anadromous Species of the Cape Fear River System, UNC, Wilmington

Phases of Hybrid Striped Bass Production:

1. Phase I fingerling production
-Generally to about 2" (1-2.5")

2. Phase II fingerling production
-Range from 3 to 10 inches (average 4-6")

3. Phase III or Foodfish Production
-Range from 0.7 to 4 lbs (most desirable market size is 1.5 to 2 lbs).

The production of phase I and phase II hybrid bass is covered in Hatchery Management I and II.

Production of Market-Size or Phase III Fish

Pond Culture
Since the late 1970's, production of large striped bass has been in practice at the Edenton National Fish Hatchery, where they have used pond culture to produce, maintain and spawn domesticated striped bass broodstock from five different Atlantic strains.

During the early 1980s attempts to produce stripers and hybrids in earthen ponds by some commercial farms in California, Maryland, and elsewhere was met with some success. In the late 1980s Carolina Fisheries was established in Aurora, NC to commercially produce market-size Hybrid Striped Bass in earthen ponds and was the first financially successful pond-based farm. It has been followed by many others in eastern North Carolina. In all twenty eight farms were established by 1998, thirty five by 2000.

In all, the largest pond-based farm is located in northern Mississippi, covering 600 acres (larger than all others combined).

"It may be the only farm-raised hybrid striped bass farm in Mississippi, but it is the largest such operation in the world."
From Nature’s Catch is largest striped bass farm in the world

Current Pond-culture Techniques
Earthen ponds should average about three acres in size, but can range between 1-5 acres and 4-8 ft. in depth. Production can be in fresh water, but minimum hardness and alkalinity values of water should be 100 ppm.

Weed control is an important contributing factor in good production, though management may be difficult in clear, hardwater ponds. Ponds should be filled during winter and fertilized in at the beginning of late winter and continued into early spring at high rates with liquid 10-34-0 or phosphoric acid to promote phytoplankton bloom to adequately shade the bottom.

Phase II fingerlings may be stocked after filling the pond. Generally they are more readily available in spring than any other time of the year. When temperatures are moderate, handling the fingerlings cause the fish less stress.

Ask for health certification by a qualified veterinary lab to make certain the fish are healthy, well graded, and sufficiently large enough to produce adequately sized marketable fish in one growing season. Though this may vary according to geography. Use the same method for estimating average size and numbers of fingerlings as outlined for catfish. In eastern North Carolina, a one hundred gram fish will grow to about 1.5 lbs in one growing season.

Stocking rates can range between two and five thousand fingerlings per acre. Optimum results have been obtained by stocking between 3000-3500 per acre.

Acclimating Fish to Water
As with any species of fish, fingerlings should be acclimated to water temperature before stocking them into the pond. This involves pumping water from the receiving pond into the haul tank over a period of 20-30 minutes until temperature and pH are approximately equal. A difference in temperature which comes to more than 10°F, is considered large and a longer acclimation period is required. Three minutes for every degree up and 1.5 minute for every degree down.

Hybrid Striped Bass are normally fed a diet consisting of 38% protein and 8% fat, but better results have been achieved using a feed containing 40% protein and 10% fat. A feed that is a mixture of both floating and sinking pellets is best. Hybrid Striped Bass sometimes feed slower after satiation, and all-floating feed may end up going to waste on the embankment.

Feeding rate should be around 2% of body weight per day, depending on:

1. Age
2. Size
3. Water temperature
4. Time since last feeding
5. Water quality
The best method to determining appropriate feeding rate is by observing feeding activity and adjust accordingly.

Good water quality is crucial in production. Bass are less tolerant of poor water quality. Pay careful attention to DO (Dissolved Oxygen levels) which should never fall below 4ppm. The dissolved oxygen level should consistently be kept above 5ppm. Aeration capacity is required for production. A three acre pond should be outfitted with a 5 horsepower electric paddlewheel aerator. Variable horsepower aerators should be outfitted on larger or smaller ponds. Sometimes additional aeration is required, and is usually supplied with PTO-driven paddlewheels. Most farmers have one tractor with PTO paddlewheel for every four ponds on the farm.

Keep ponds salted to increase chloride levels up and prevent problems with nitrite.

To keep ammonia levels down and ponds cool during hot summer weather it may become necessary to frequently flush ponds. Hybrid Striped Bass is really more of a coolwater than a warmwater species.

Disease and Parasites
Yellow grub (Clinostomum complanatum), a digenetic trematode is the most economically devastating disease & parasite problem encountered. These parasites are characterized by their life cycle... having a definitive host (birds) a first intermediate host (snails) and a second intermediate host (fish).

Rams Horn Snail - An intermediate host in the life cycle of the Yellow Grub.
Photo by author, 2007
No effective FDA-approved treatment exists for yellow grub, though it may be controlled by eliminating the predatory birds (primarily cormorants and great blue herons) and/or the snails.
• Trained dogs can chase away birds or a depredation permit can be obtained to shoot them. By controlling weeds snails can be effectively reduced, particularly bottom-rooted macrophytes on which they feed. Introducing snail-eating fish is now one area of research being looked into.
• Snail numbers may be greatly reduced by draining and drying ponds annually. Quicklime (CaO) may be applied to remaining puddles or copper sulfate at 10 ppm to kill any remaining snails. Be aware both treatments will also kill any fish remaining in the puddles.

ICHTHYOPHTHIRIUS MULTIFILIIS, or "ICH" for short, is one of the freshwater fish diseases. Ich is a waterborne microscopic parasite that reproduces in small colonies among the slime coat and/or skin of your fish. A common sign of beginning stages of Ich infection are what is called "flashing", where fish will swipe against aquarium decorations or the gravel at the bottom of the tank in an attempt to seemingly scratch themselves. Only one or two small colonies will appear at first, and be very difficult to identify until this infection advances to near maturity. The irritating Ich parasite, if untreated, will very rapidly overwhelm the fish with tiny white spots, making your fish seem as though they have been sprinkled with salt.
Source: http://www.fishtankguy.com/health.php

Ich (Ichthyophthirius multifiliis) is a protozoan parasite that sometimes causes devastating losses in commercial Hybrid Stripe Bass, and other species. This parasite is difficult to treat. The best prevention method is through the use of disease-free certification of incoming fingerlings and avoid use of water supplies containing wild fish.

Other common diseases include the bacterial diseases MAS (Aeromonas spp.) and columnaris (Flexibacter columnaris). Terramycin medicated feed is used to control these and other bacterial diseases, but is not specifically approved by the FDA for use on hybrid striped bass intended for use as human food.

Other disease problems have been reported but are either secondary (such as fungal diseases) or relatively rare.

Harvesting Hybrid Striped Bass
Hybrid Striped Bass are harvested using standard seining techniques. They are sorted by size and packed in 100 lb boxes on ice for shipment to East Coast markets, primarily Northeastern US and Florida. Some fish are sold live, to live-haulers for shipment to Asian-American markets in the Northeast.

Single-Pass Tank/Raceway Culture
Successful culture of Hybrid Striped Bass in single-pass tanks and raceways are nearly as lucrative as pond culture, depending on circumstances. Fish grown in these systems require the same basics in feed and water quality. Some advantages are the lack of problems with yellow grub, as long as the fingerlings are grub-free. There are better feed conversion than in ponds and harvesting is easier and less costly. Such factors help offset increased costs associated with intensive culture in tanks and raceways.

Recirculating System Culture
Sufficient attempts have been made to grow Hybrid Striped Bass in recirculating systems, but many failed due to problems associated with water quality and disease.

Cage Culture
Cage culture of Hybrid Striped Bass holds promise in locations where water quality is sufficient for good health and growth rates throughout the growing period. Feeding in brackish public waters is likely to cause degradation of water quality around the cages. If large numbers of fish are fed in many cages in a semi-closed brackish water body (such as a small sound or lagoon), a generalized reduction in water quality over the whole area is likely. Even if cage or net-pen culture is demonstrated to be technically and economically feasible, it may not be politically acceptable in many areas, and is likely to be regulated out of existence before it can get started.

N.C. trout, catfish sales increase

2007-03-11T14:51:00.000-07:00

Shoppers buying N.C. trout, catfish

(Winston-Salem Journal (NC) (KRT) Via Thomson Dialog NewsEdge) Mar. 6--The N.C. Department of Agriculture and Consumer Services said yesterday that the state's sales of farmed trout and catfish rose last year because more people understand the nutritional value of fish.

According to the department, trout sales increased about 10 percent, to $7.2 million last year. Catfish sales increased 19 percent, also to about $7.2 million.

North Carolina ranks second, behind Idaho, in trout sales, the department said. The state ranks sixth in the country in catfish sales.

Read the entire article...

Stages of Fish Larvae Development

2007-03-11T10:16:00.000-07:00

I've purchased a copy of Zooplankton of the Atlantic and Gulf Coasts (A Guide to Their Identification and Ecology) by William S. Johnson and Dennis M. Allen.

While skimming this book I found many useful and informative sections on groups of zooplankton, including fish. Below is an example of the descriptive illustrations found in this book.

Understanding fish larvae is important in Aquaculture, including knowing the proper timing for changing between food sources, as in transferring fish from hatchery to growout ponds. An example can be found in the sidebar, with a list of catfish life stages.

Typical fish egg

Illustrations from Pg. 270, Zooplankton of the Atlantic and Gulf Coasts
Anatomy of larval fishes, based on naked goby Gobiosoma bosc. Middle illustration shows an early feeding stage that has yet to develop fin rays. The last in the series is a juvenile, which is generally defined as a young individual that is fundamentally the same as the adult in morphology.

Excerpts from Zooplankton of the Atlantic and Gulf Coasts, pg. 269-271
"A few species attach sticky eggs to objects at the bottom, but most are simply released into the water column; some are bouyant and some sink to the bottom (demersal eggs). Fish eggs are usually spherical, from 0.5 to 2 mm. The transparency of most of most fish eggs distinguishes them from the typically opaque eggs of invertebrates. Recently spawned eggs have oil droplets or "yolk" that support early development. Development of an embryo is usually rapid, and often within hours of spawning, the outline of the young larva is easily seen within the egg. At hatching, the now-free larva still has a yolk-sac attached to support early development.
The change from the larval planktonic phase to the juvenile and adult lifestyle often involves "remodeling" of the basic larval body plan, resulting in major changes both in morphology and in functional capabilities. The newly hatched yolk sac larvae grow and develop using nutrients provided in the yolk. As the larvae grow, they add musculature, fin rays, and sensory capabilities. Newly hatched larvae are feeble swimmers, but swimming capablities improve rapidly as larvae grow. Some larvae show schooling behavior at a relatively early age. As swimming speed and endurance increase, some larvae show distinctive patterns of vertical migration that may be associated with predator avoidance, feeding migrations, or selective tidal transport. Early larvae are usually transparent with pigmentation increasing during growth.
When the yolk sac is resorbed, the larvae enter the critical "first feeding" stage where they must find and capture prey in the plankton or perish. First foods are quite small; rotifers, ciliates, and copepod nautilii. Vision develops early, and most larval fishes are visual feeders. Prey are perceived at close range, usually within one fish body length... Prey detection and selection seem to be based on prey size more than on any other factor, but motion and color may come into play. Feeding stops in complete darkness but may continue in moonlight. It is interesting that larvae can see in and feed using ultraviolet light, a capability lost in many adults."

Zooplankton of the Atlantic and Gulf Coasts (A Guide to Their Identification and Ecology) by William S. Johnson and Dennis M. Allen is available at amazon.com

Pleurotaenium and Desmids

2007-03-09T13:35:00.000-08:00

After a week observing algae under the microscope, I've came across numerous algae which share similarity with chain diatoms, but I don't feel these are the same. There are always two sections to this algae strand, and today I caught this particular organism moving itself, similar to euglena (wmv, 10804 k), except the body is not flexible and does not bend. I'm still unclear on the precise identification but feel it must be related, if only distantly to this particular species (below).

A Desmid - Pleurotaenium sp. Found in Sheepwater. It is a green alga, and the wavy lines in the middle distinguish this from other desmids. (x400) Photo: 21st April 2006.
Source: Freshwater and Terrestrial Algae

Example one from my algae sample

Original high resolution image
Approx. 400x magnification w/ digital camera

Gamophyceae: Zygnematales: Desmidiaceae
Pleurotaenium
Nägeli
Genus: Cell body long cylindroid; a slight constriction at center; cross section of the semicells spherical, slightly swell at the center but without a folded structure as Docidium; slightly tapered toward both ends, which are truncated and smooth or surrounded by granules or various small structures; laterally straight or wavy, with spiny projections in some species; 2-10 ribbon-like chloroplasts in each semicell; with many pyrenoids; a vacuole containing active granules at both ends same as in Closterium; cell wall mostly dotted, but with spines or other patterns in some species (Illustrations of The Japanese Fresh-water Algae, 1977).
From Pleurotaenium, Protist Images

Google images contains numerous specimen with likeness and similarity.

Revista Brasileira de Biologia
Desmids, and specifically Pleurotaenium, see diagram in middle of the page.
"Figs. 17-19 – Pleurotaenium eherenbergii var. eherenbergii; Figs. 20-22 – Pleurotaenium trabecula var. elongatum"

Enlarged Image
Example two from my algae sample
Approximate 100x magnification
A similar algae, is the Gonatozygon and here. Some algae groups which share resemblance with my samples, are also available under Desmids

Desmids can be recognised by their symmetry. Two, mostly ornamented semi-cells are joined by a narrow connection called the isthmus. This where the spherical nucleus is situated. Each semi-cell houses a large, often folded chloroplast. One or more pyrenoids can be found. These form carbohydrates for energy storage.
[A specimen very similar to mine, is located under "Where can you find Desmids?"]
DESMIDS by Wim van Egmond

Enlarged Image
Example three from my algae sample
Approximate 1000x magnification w/ digital camera

Enlarged Image
Example four from my algae sample
Approximate 40x magnification

More high resolution images, available here.

Proper Algae Plankton Identification

2007-03-09T10:50:00.000-08:00

Here's one example of the problems with identifying algae species, and I haven't really even began documenting what I'm seeing under the microscope.

To give an idea of scale, it's a grain of sand... and beside it sets the organism in question.

Three of them.

Going by the "Aids to the Recognition of Fresh-Water Algae, Invertebrates and Fishes," a brief 24 page paper which my instructor photocopied for me to use... the closest, is Merismopedia. But, that may be wrong. This species could also be, "Crucigenia rectangularis," both look practically the same.

Here's merismopedia.

Needless to say there may be others that look similar or near identical.

I've surfed the web, and really ran into some problems with species identification -- for that matter, proper classification into genus.

This was written by a biology instructor, in regard to the trouble I've had identifying species writes:

The proper way [to collect plankton] is to use properly calibrated and sized plankton filters.

I recognize the eagerness which you show in searching out and trying to identify the enormous range of things you can find. It is what is found in the best students; those truly interested in learning as opposed to those who simply want to get through the required laboratory exercises and go home. Unfortunately, there are not simple answers to questions, even "simple" questions like "what is this". Especially not when the sample comes from teaching aquaria that may be filled with all sorts of exotic things. You are faced with more than the "common pond life" that the simple-minded keys I referred you to are intended to help with.

You are also learning the fact about photographs -- some of yours are unusually good but they simply do not convey the detail of information that a trained eye can see, especially as the trained brain integrates the information from different views and images from different angles. That is why making drawings is so important. In a good drawing, you illustrate those features that are really important, showing them clearly. Of course the Haeckel episode reminds us that drawings are different from real life, but photographs are also different from real life. Making truly detailed and useful photomicrographs is a talent that requires special training and long practice, not to mention rather better microscopes than what you are using. In other words, there really isn't enough detail in the pictures you display to see exactly what many of the things may be. Your commentator on the artscape salt-water-microbes web site identifies things as well as can be expected.

I hate to have to tell you this, but you will have to accept that some things will not be identifiable. That will come with long experience studying with experts. The fact that one of your instructors/mentors, Terri, apparently can't identify it all should be a clue. That is why doing science is a constant learning experience. It really does take years of guided training to do some things and, even then, you still keep learning as long as you live.

So welcome to the world of real science! You are off to an excellent start. You have a long way to go but the entire trip is a fantastic adventure!
- R. Norman

Aquatic Food Web and Aquaculture

2007-03-09T05:16:00.000-08:00

The past week I've spent a lot of time with my new toy, the microscope and realizing the difficulty of properly identifying phytoplankton/zooplankton, decided to order a few select books which may can help in that arena.
One of those books I chose after an extended surf on amazon is Pennak's Freshwater Invertebrates of the United States. I received the book just yesterday, have skimmed over it and rather pleased with the sheer number of illustrations, though the vast majority are line-drawings and not in color. Nonetheless it appears it will make a valuable reference book on freshwater invertebrates. There's a large section dedicated solely to rotifers or, properly rotifera (Wheel animals) Chapter 7 pgs. 129-190, a subject that's raised often in Aquaculture. It contains a rich collection of illustrations to help identify individual species of rotifers.
From looking it over, it seems this book would be best approached if you read the introduction first instead of skipping to latter chapters. The introduction seems to be plentiful in information that brings the reader up to date on issues related to freshwater invertebrates.

In our class, the instructor gave me a copy of Zooplankton Succession and Larval Fish Culture in Freshwater Ponds, by Gerald M. Ludwig, (a full list of documents in pdf format, are listed here http://srac.tamu.edu/fulllist.cfm). In this paper it tells the proper timing to add fish to the pond. You don't want to put the fish in too early, for lack of plankton (their food source), and too late can result in the zooplankton eating the fry:

Tiny fry eat only tiny prey, but tiny fry are preyed upon by many creatures bigger than they are. It is important to know the size of the fry you are stocking and to make sure that the pond you are putting them into contains plankton of the size that will be their prey and is also void of creatures that will prey on the fry.

Fish fry eat zooplankton, phytoplankton and tiny plants and animals attached to objects on the pond bottom... Most fish fry eat three main types of zooplankton-- rotifers, copepods and cladocerans. For the tiniest fish fry, small rotifers may be the only zooplankton small enough to eat. For larger fry, the smallest rotifers may not provide enough nutrients to make chasing and ingesting them worth the effort. Copepod nauplii, which are just hatched copepods, are important first foods for larval fish, too. Protozoans may also be eaten, but little is known about their contribution to fry diets.
- Zooplankton Succession and Larval Fish Culture

The document goes on to tell the stages of succession in ponds, the first group appearing in ponds are the rotifers which obtained their name from their "wheel organ," a ring of cilia that appears to rotate around the mouth. Rotifers can reach maturity in 2-8 days, and hatch from "resting eggs" that survived on the bottom of the pond while it was dry. Most are asexual, until conditions are harsh, then they become sexual and and resting eggs are produced again.
Rotifers are followed by copepod nauplii, the second largest group to appear in ponds, and reach maturity about 18 days after the pond is filled. With their growth (up to 2-3mm) they provide larger food source for larval fish. Only larger fry such as catfish have large enough mouths to eat adult copepods.

Although copepods may be prey for larger fish fry, sometimes the roles are reversed. Introducing small fish fry into a pond full of large copepods can be disastrous... When cyclopoid copepods are prevalent, they may eat all the fish fry stocked.
- Zooplankton Succession and Larval Fish Culture

The document explains proper timing of fry stocking, such as "the proper timing of fry stocking in relation to filling and fertilizing the ponds, can make the difference between having an abundant harvest or a complete crop loss... and optimum growth of fry."
The entire document can be downloaded at http://srac.tamu.edu/fulllist.cfm).

To understand the aquatic food chain itself, and problems associated with reliable research in this area, is explained in broader detail in Pennak ...

Page 32, Pennak's Freshwater Invertebrates of the United States
"During the past two generations the literature of aquatic biology has been replete with "productivity" and "trophic level" studies. It is unfortunate that most of these studies are misleading because they (1) are seasonal rather than year round, (2) have been conducted on complex (rather than simple) ecosystems, and (3) are based on only a fraction of the species making up a particular ecosystem. As a consequence, the generalizations postulated in many of these investigations are open to doubt and modification. Actually, a much more fruitful approach of population dynamics and interrelationships involves habitats characterized by few species and few niches. Examples are alkali and saline ponds, relatively barren alpine lakes, spring brooks, very small ponds, warm springs and small mountain streams. Using such bodies of water, it should be relatively easy to determine food habits of individual species and to make quantitive estimates of populations. Productivity indexes, food cycles, energy transfers from one trophic level to another, species interactions, and seasonal population fluctuations are all important ecological concepts that should be derived from such studies on a year-round basis. It is important to note that the measurement of associated physical and chemical factors in small streams, lakes, and ponds is simpler than in more complex types of aquatic habitats and in terrestrial habitats.

Fig. 1.12 Basic features of aquatic food webs. See text for explanation.
Nevertheless, even in the simplest aquatic habitats the determination of pyramids of numbers and food chains (or, better, "food webs") is an involved problem, and only a very few thorough and inclusive studies have been attempted. The great majority of trophic investigations are concerned with only a few energy or biomass transpositions, the remainder being only roughly estimated. In any such study the basic role played by detritus [that is, loose fragments or grains worn away from rock and/or disintegrated, eroded matter] and bacterial action should not be minimized. In a schematic fashion, Fig. 1.2 shows the fundamental food interrelationships for any aquatic habitat, regardless of size and complexity. Only recently have aquatic ecologists come to realize the overwhelming role of detritus in the food web. The significance of various segments of this diagram vary enormously from one habitat to another. Some habitats, for example, have few or no fishes; other habitats have no rooted aquatics or a poor substrate fauna.
Solid lines indicate consumption or utilization of food. Broken lines indicate death and disintegration of detritus as the result of cetain bacterial activities. The circle arrows originating and ending at "zooplankton," "fish," and "substrate fauna" are meant to show that certain species in each of these categories are carnivorous and feed on other individuals within the same category. Actually each such category may represent two, three, or more trophic levels. "Substrate fauna" includes all bottom invertebrates as well as protoctistans, micrometazoans, and macrometazoans associated with the surface of rooted aquatic plants and other objects. By inference, "bacteria" also includes molds and their activities.
For simplicity, certain minor aspects of this food web have been ommitted. For example, the contribution of excretory materials to the main reservoir of dissolved nutrients is not shown. By inference, "fish" should include other vertebrates, such as frogs, salamanders, and turtles. Not shown, but nevertheless intimately concerned with the continuing balance within the web, are the nitrogen, sulfur, and phosophorus cycles. These are fundamentally similar to the same cycles operating in terrestrial habitats."
Source: Pennak's Freshwater Invertebrates of the United States, pg. 32-33

yep, Pennak is a great reference for freshwater inverts.. I have a 1978 edition on my shelves -- haven't used it in awhile since I really don't do FW stuff anymore. I just pulled it out and checked out the intro.
You're right -- it's a good discussion on the FW food web.

Enjoy your new treasures!

Terri
www.ncseagrant.org

Centropyxis

2007-03-05T07:58:00.000-08:00

According to Aids to the Recognition of Fresh-Water Algae, Invertebrates and Fishes this creature has the most visible similarities in common with Centropyxis.

Google images produced a variety of similar creatures, so I'll take the chance this creature may be classed among Centropyxis.

Enlarge image to full resolution
Magnified at 100x
Additional photographs of Centropyxis

I don't know, I don't think it's /Centropyxis/. Just doesn't look like it to me. Spines are in different places. Just my 2 cents.

terri
www.ncseagrant.org

Cypridopsis

2007-03-03T13:02:00.000-08:00

... my site is the official place for errors, blunders and bad identification -- where the information is compiled until it's gotten right.

Here's another that hasn't had any feedback. I photographed two of these.
cypridopsis.html

At least we know the little sketch form the Aids to Recognition is correct. That's one positive. *smile*
-Sharon
I do believe that is an ostracod! Nice find.
terri
www.ncseagrant.org

Cypridopsis

According to table with crustaceans: cladocerons, copepods and ostracods, from Aids to the recognition of Fresh-water Algae, Invertebrates and Fishes

Collection of my Cypridopsis Photos
Cypridopsis Images, Page One
Cypridopsis Images, Page Two
Cypridopsis Images, Page Three
Cypridopsis Images, includes video clips, Page Four

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Diatoms Photos

2007-03-03T09:00:00.000-08:00

Of growing curiosity to me...

Diatoms

For brief but insightful explanation of what diatoms are, see my earlier post on Diatoms.

Also available online, my collection of photography of Diatoms.

Protococcus

2007-03-02T21:00:00.000-08:00

From Aids To The Recognition of Fresh Water Algae, Invertebrates and Fishes

More photos of Protococcus

Closterium

2007-03-02T19:11:00.000-08:00

I am taking a shot in the dark at what the identification of this particular creature is. The closest thing I've came across that looks anything like it,

Closterium is a desmid, a microscopic green algae that occurs in all types of freshwater habitats. Desmids are typically one-celled, though sometimes filamentous or colonial, and are divided symmetrically into semicells connected at a central point. Closterium is characterized by a sickle shape and sometimes contains gypsum crystals.
Source: Closterium Video No. 1

Source: Closterium Tables, XXVII, XXVIII, XXIX, XXX

More Closterium Images

(+/-) Enlarge Photo
Cloisterium resting near Cypridopsis

Merismopedia

2007-03-02T13:56:00.000-08:00

This species could also be, "Crucigenia rectangularis".

According to Aids to the Recognition of Fresh-Water Algae, Invertebrates, and Fishes which John (BCC) has given me, the closest match to this little phytoplankton, is Merismopedia.

Arrows point toward tiny merismopedia, three of which set beside a grain of sand magnified about 100x.
More photos of Merismopedia

Diatoms

2007-03-02T06:23:00.000-08:00

After observing diatoms under the microscope at length I've noticed some of those normally seen as loosely floating diatoms are hooked together, aside of the obvious with chain diatoms. Chain diatoms it turns out, are due to their asexual reproduction habits... the cell divides, and a chain builds over time.

Figure 1 and 2

Sexual reproduction "Diatoms can reproduce in two different modes, sexual and asexual. Diatoms have a unique "shrinking division" mode of asexual reproduction. After cell division, the two valves of the test separate. Each forms the epivalve of a daughter cell, and new hypovalves are secreted within each of the parent valves. The result is one cell that is the same size as the parent cell, and one cell that is slightly smaller. Due to the rigidity of the test material, growth of the cell is impossible once the test is secreted. Thus, the average diatom size gets progressively smaller with each round of replication."

Figure 3 and 4
Diatom life history and interannual variation in diatom community composition
"The typical diatom life cycle is composed of many generations of asexual cell division and cell size decrease until a episode of sexual reproduction restores the maximum cell size. Populations that are unable to reproduce sexually will eventually go extinct. For many species of planktonic diatoms, sexual reproduction has never been observed and very few of the observations are of free-living populations, presumably because the episodes are typically brief (days to weeks in duration) and rare (years to decades apart)."

Figure 5 and 6

"Diatoms are unicellular (single cell) alga which are lumped in with other organisms and collectively referred to as plankton. Diatoms belong to the Kingdom Protista and the phylum Bacillariophyta. They inhabit both freshwater and marine environments as well as semi-aquatic and moist habitats. Diatoms live free floating, attached to a substratum (plants, sand, rock and animals), or joined to each other. They accomplish this by way of a gelatinous extrusion used for attachment and locomotion (some species). Diatoms are primary producers that contain chlorophyll a and c and the carotenoid fucoxanthin which accounts for their golden brown color. Their cell wall is composed of silica (silicon dioxide) and can be very ornate. Diatomaceous earth (dirt with diatom “shells”) is mined and used as polishes (toothpaste), abrasives, filter components and insecticide. Diatoms reproduce asexually by dividing the frustule in half. The frustule is composed of the epivalve and hypovalve. With each asexual reproduction, the diatoms are reduced in size until the diatom undergoes sexual reproduction. After sexual reproduction, the original size of the diatom is re-established and the process begins anew.
The monitoring of streams, rivers and lakes to insure water quality is extremely important. It is known that individual species of diatoms have specific and well defined water quality tolerances."
From Diatoms Web Page, John Carroll University

Figure 7 and 8

Diatoms are the most common phytoplankter. They are one celled producers... [and] are important oxygen producers in marine ecosystems (usually the first step in the food chain).
Asexual reproduction occurs with diatoms in good conditions in a unique way so that some get smaller and smaller until they are too small to function properly. This occurs when each frustule makes a new part - the original epitheca makes a new hypotheca inside the reproducing diatom resulting in a diatom the same size as the original diatom. The original hypotheca makes a new piece of frustule that will become a hypotheca inside the reproducing diatom - the original hypotheca now becomes an epitheca resulting in a diatom smaller than the original diatom. If this goes on for many divisions (as happens when conditions are very good and splitting can occur every few hours) there are a wide variety of diatom sizes concentrated in the water - some large and many small. The very tiny ones can no longer carry on cellular activities - these are the ones that become sexual. They form eggs or sperm (depending on their sex that was not obvious before). The sperm is released and when it fertilizes an egg the resulting zygote drops the tiny frustule, swells up to a large size and secrets a new large frustule.
From Marine Life: Plankton

Alonella - Zooplankton

2007-03-01T22:33:00.000-08:00

The Genus Alonella is a group of very small waterfleas. Fine features of the carapace and postabdomen are used to distinguish among species - necessitating use of a high-powered light microscope at a minimum.
Source: Genus Alonella

Large image, 1298 x 1289 pixels, 295 k

I am not certain yet which species this waterflea would be classified among, but I'm positive it's Zooplankton and fairly certain it falls within the genus Alonella.
This photo was created by fine-focusing at two separate depths and merging the photos. Nice seeing its wee little ~~legs~~ (antennae?) in detail.

More Photos and Video of Alonella

Freshwater Micro-Organism

2007-02-28T22:09:00.000-08:00

Larger image (Magnified above at 40x)

Another freshwater critter of curiosity I caught dancing around among the algae. Though its green like algae, it moves about on its own. A noticeable feature, was the bright reddish spot...

Sharon wrote: I noticed on your page you have a very similar phytoplankton to the one I found.

But it is not the same species. I want to identify the species. Mine has a red dot on it, which looks like an eye, but I do not believe it is in an eye.

Please can you help me to identify this species?

Thank you, Sharon Mooney

------------

It's almost certainly a euglenoid.

IF it was flexible in motion (e.g., the cell body itself flexible, not just the flagella), it is almost certainly a member of the genus Euglena.

The red spot is in fact an 'eyespot' - it's a very primitive eye that allows the euglena to detect light -- a big advantage for a mobile photosynthesizer.

Dr. Rochelle Sturtevant
Extension Educator
NOAA
Great Lakes Sea Grant Network
Great Lakes Environmental Research Lab

Heres the same magnified by combination of microscope and camera

Large Image

Large Image

Large Image

Large Image

Photos and Video of Euglena, Page One
Photos of Euglena, Page Two
Euglena Images, Page Three

Euglena Images, Page Four

Hit the Microscopy Jackpot

2007-02-28T16:26:00.000-08:00

I just figured out how to capture images, nearly picture perfect as they appear under the microscope lens. My camera (Canon PowerShot S3IS) has a setting for "Sports" shots. It captures shots split second while reducing blur. So, the incredible result appears below:

Enlarge image
Image #1 magnified at 40x

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Image #2 magnified at 40x

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Image #3 magnified at 40x

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Image #4 magnified at 40x

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Image #5 magnified at 40x

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Image #6 magnified at 40x

Feeding the Catfish

2007-02-28T14:41:00.000-08:00

Chad at BCC told us he was going to feed the catfish, and if we wanted to see them come up to eat... to follow. I captured some neat shots today, with the catfish surfacing for food pellets.

Image enlargement
Catfish surfacing...

Image enlargement
Catfish surfacing... and food pellets floating nearby in the water.
Catfish video - Windows Media Player
feeding_catfish.wmv
4967 kilobytes / 4.96 meg

Volvox

2007-02-28T14:11:00.000-08:00

Several years ago (around 2003) I made my mind up that one day, I was going to photograph a volvox after learning about these fascinating little creatures. They're somewhere between the plant and animal kingdom. A volvox is a colony of sisters, but they use photosynthesis / chlorophyll like plants do.

Made a goal, stuck to it, and made it happen.
Today, after all this time, I captured my first volvox. Mind you, it's not much of one, but it is a volvox. And, for all case and purpose, that's what matters. I've tried multiple samples of algae over the weekend, and today I tried a new pond out (out back of the Aquaculture facility) and in the dissection microscope, I saw a volvox. Twice it was lost behind other material, but alas I did capture it on my camera.

Enlarge Image The volvox was located at the lower right hand corner of the photograph. Photograph made at Brunswick Community College by me of course. *smile*

Later this evening, I did capture a clean, green little volvox... all to itself, and made video and photos of it.

Volvox

Additional Links
Volvox, Images and Videos, Pg. 1
Volvox, Photographs, Pg. 2
Volvox, Photographs, Pg. 3
Volvox, Photographs, Pg. 4

Identifying Algae

2007-02-28T07:57:00.000-08:00

Enlarge image
Image captured by digital camera. I had more success at capturing a clearer image, in fewer shots by _not_ using "Super Macro" feature on my camera.

Enlarge image
This image was produced by the microscope software.

The question is, which strain of algae am I looking at? Several in the guide my instructor gave me bear resemblance to those in the charts.
17. Spirogyra (comparing with Google images, Spirogyra appears to bear similarity, but I have my doubts this is the identification.)
18, 19. Mougeotia though long and divided into section like my sample, I have my doubts.
20. Zygnema *also shares many similarities with the sample I've captured, but I have my doubts this is the identification.
28. Microspora

Although Microspora appears to bear striking similarities as well.
Source: Class Chlorophyceae
29. Ulothrix, possibly...
30. Oedogonium, another possibility.

Spring Break

2007-02-27T19:55:00.000-08:00

Since this is my "college journal" of sorts to tell the world my joy, whoa and tribulations... I'm really looking forward to upcoming Spring Break. aaaarrrrggghhh... I really hope I'm going to be able to catch up on all the loose ends with my school-work.

John (instructor at BCC) recently gave me a printout, "Aid to the recognition of Fresh-Water Algae, Invertebrates, and Fishes"... after peering through the microscope for several hours and seeing such diversity of life-forms in different samples of water (three to date),
1. John's "Algae tank",
2. a sample strained from a salt-water tank, and lastly,
3. the BCC Aquaculture Ctr. has a tiny pond with lily pads growing in it. I began seeing the significance of the paper he gave me.

Lilypads in a tiny pond in front of BCC Aquaculture Ctr.
I'm thinking to go through the samples one at a time, and capture each in photograph, and video if its interesting...

What's frustrating... it may take 25 or 50 or more shots, via exterior digital camera (using super-macro, to even get one good clear image through the lens of my microscope). Even these shots... the best of the batch, came out blurry. The software program which was included with the microscope I purchased is good, but it can never match the light, and quality of the real-life scene I'm seeing through the lens of the microscope. Capturing a high-focused, quality and true-to-life image, takes a lot of time, and needless to say, a lot of work.
-- ... then document more detailed information about the lifeform...
what it is, and what it does. This, along with so many other things I'm caught up in, like our final research project (I chose disection of a fish) and honestly haven't made the first crack at working on it [too many other things I'm wrapped up into] I have my schedule stretched out so thin, to do and accomplish so much, I emphasize aaaarrrrggghhh... I need more time to do it all.
I'm over-extended. But I really do love it. The Aquaculture center has so many interesting things going on it. I just sorted through some of my recent photographs, like this one of the crawfish the center has growing in a trough out in the hatchery.

So many interesting things to learn about, but so little time. College was definately the right choice for me, although I'm not the youngest student (mid-late 30's) but it's never too late to start learning something new. I just couldn't get enough information from the web, and I couldn't afford all the books on Amazon required to get where I want to be in my personal studies / hobbies. Our local meterologist George Elliot, WECT News 6 said, when you stop learning new things, you stop growing. So, it's never too late to get back into school.
My interest in marine biology has been growing since I first became interested in Cetaceans (whales, porpoise, dolphins) back in 2001, followed by a growing interest in mollusks, which developed from some trips to the beach and sifting through beachdrift... little creatures often taken for granted by tourists who walk right by, stepping on the shells and sometimes breaking them... which is bad, on the occasion, say an Angelwing, a very fragile shell washes up in one piece on the shoreline, and they do on a rare occasion. It dawned on me, each of the species I was looking at, have a unique story to tell. I began finding out what those stories are. Marine Biologist Terry K. Hathaway with NC Sea Grant has helped to identify most of those species, and I really have appreciated the input.

Right now, Algebra is what's dragging my schedule down. My Algebra instructor told me I should have taken his course, when not taking as many other courses -- making more time to focus on Algebra. But on a positive note, I'm about to complete another course that ends mid-term, and that may free up more time to devote to Algebra studies, at least hopefully, ideally...

Omega 3 Fish Oil Reducing Heart Disease

2007-02-27T19:12:00.000-08:00

Yesterday "Doc" Doug Holland told our Aquaculture class that especially coldwater fish is good for your health, to eat it at least twice a week. I didn't understand why exactly, but he said it has positive effects on heart disease, "hardening of the arteries"...

I just checked the web for further info (a government source will suffice):

Dietary sources of omega-3 fatty acids include fish oil and certain plant/nut oils. Fish oil contains both docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), while some nuts (English walnuts) and vegetable oils (canola, soybean, flaxseed/linseed, olive) contain alpha-linolenic acid (ALA).

There is evidence from multiple studies supporting intake of recommended amounts of DHA and EPA in the form of dietary fish or fish oil supplements lowers triglycerides, reduces the risk of death, heart attack, dangerous abnormal heart rhythms, and strokes in people with known cardiovascular disease, slows the buildup of atherosclerotic plaques ("hardening of the arteries"), and lowers blood pressure slightly. However, high doses may have harmful effects, such as an increased risk of bleeding. Although similar benefits are proposed for alpha-linolenic acid, scientific evidence is less compelling, and beneficial effects may be less pronounced.

Some species of fish carry a higher risk of environmental contamination, such as with methylmercury.
Source: Omega-3 fatty acids, fish oil, alpha-linolenic acid

Recently, I bought a tub of Wal-Mart's Omega 3 Fish Oil, 1000 mg, based solely on the fact, my parents use to buy it at times. I thought it had to do with heart-related health.

There seems to be quite a lot of information on what Doc said, about the positive effects Omega fish oils have on reduced hardening of the arteries.

Microscopy of Algae

2007-02-26T10:02:00.000-08:00

The small splot in the middle is the tiny drop being magnified.

...at 40x the size of the actual drop.

Here's the drop magnified.

Pretty amazing toy.

Freshwater Microscopy

2007-02-24T19:08:00.000-08:00

Two new items on the web.

John Baka, instructor at Brunswick Community College's Aquaculture Program shares photos of pests that affect North Carolina fish culture... fish eggs, and other great stuff.

John and Fish Eggs at BCC

Freshwater Microbes
Photos of microscopic organisms from a freshwater sample. Videos and images of freshwater algae and insects.

Photographs of Snails, Catfish and Lily

2007-02-21T19:23:00.000-08:00

Here's a recent addition to the alternate site with my first microscopy shot of Qui nosce mysterium that's Latin for who the heck knows? and a lot of other "neat stuff" taken at the college.

John and Chad will have to help me identify all those neat critters that'll be seen floating up under the microscope...

WOW, Sharon. What a neat shot! The only thing I see in there is a chain of diatoms that I can't identify -- it could be /Melosira,/ /Skeletonema/, or /Biddulphia/.

I would love to see more plankton photos when you get them! I enjoyed the other photos also.

Terri K. Hathaway
Marine Education Specialist
North Carolina Sea Grant

A snapshot of Lily, the College's Bird-Dog

Video and Digital Photographs of Microscopic Worms

Videos and Photos of Microscopic Worms, February 22, 2007, Salt Water Sample from BCC

Asia-Pacific Marine Finfish Aquaculture

2007-02-08T04:43:00.000-08:00

The latest eMagazine (Oct-Dec 2006) of the Asia-Pacific Marine Finfish Aquaculture Network is now available for download and the following topics are in this latest issue:

1. Second Workshop on Economics and Marketing of Live Reef Fish in the Asia-Pacific.

2. Marine finfish market information and aquaculture development trends in selected locations in Indonesia and Malaysia.

3. Brief overview of the 2nd International Symposium on Cage Aquaculture in Asia (CAA2).

4. Skretting Scholars take new knowledge home after NACA hatchery course.

5. Market analysis of the live reed food fish trade.

Read article in its entirety.

Breeding fish at Kenyir Dam

2007-02-08T04:39:00.000-08:00

Company in project to breed fish at Kenyir Dam
R. S. N. Murali

A Negri Sembilan-based aquaculture trader has responded promptly to a call by Prime Minister Datuk Seri Abdullah Ahmad Badawi to the private sector to play its role in turning the National High Impact Aquaculture Industry Zone (ZIA) project into a successful venture.
T. Bitara Sdn Bhd of Oakland Commercial Park in Seremban will introduce state-of-art technology from China and Japan in freshwater fish breeding at Kenyir Dam soon.
The company’s chief executive officer Herman Nyam said the multi-million-ringgit project on a joint venture basis with a foreign company was expected to be initiated after the Chinese New Year celebrations.
“We will have a brand new start for the New Year creating job opportunities for locals,” he said after visiting the proposed project site at Kenyir Dam together with his director Shamsul Bahari recently.
Nyam said the company felt Terengganu was suitable for the introduction of the latest technology as the state was investor-friendly and willing to render assistance to businessmen at any time.
“We are looking at a technology which will increase the output of fish production in a short span of time and therefore we cannot afford to have red tape imposed especially in the licensing process,” he said.
Nyam said the company’s fish project at Talang Dam in Negri Sembilan had yielded robust growth since it was started five years ago.
“With the support of the Negri government, the fish is being marketed to China, Japan, Taiwan, the United States and India,” he said.
Nyam said that fresh graduates would be given the opportunity to manage the project in Kenyir Dam once the project was launched.
“These graduates will be head-hunted to manage the project and we expect to absorb 30 of them at the pioneer stage to manage our project,” he said.
Read the article in its entirety.

Can fish farming save depleted cod?

2007-02-08T04:33:00.000-08:00

February 07, 2007
By Simon Rabinovitch
LONDON (Reuters) - Cod, a mainstay food from Britain to Brazil, all but disappeared from Canadian waters in the 1990s after years of overfishing, and scientists say a similar fate awaits the shoals of the North Sea.

But fish farms are putting cod back in North Sea water, at least within enclosed sea pens, easing the strain on wild fisheries and, fish farmers say, protecting a species that would otherwise be fished into extinction.

Off the Shetland Islands in northeast Scotland, Johnson Sustainable Seafoods is providing what it says is a model of good farming practice.

Given more space to roam around their pens and fed a natural diet, the Shetland cod farm has won the backing of Britain's Organic Food Federation.

"Fish farming can be the saviour," said Karol Rzepkowski, managing director of the company. "It takes a little bit of left-field thinking, having the right ethic and the right ethos, and it can be done right," Rzepkowski said.

RESTOCKING THE WATERS?

The Shetland farm expects to harvest 2,500 tonnes of cod this year and aims to double its output in 2008. Other producers include Pan Fish in Norway, which recently acquired Marine Harvest to become the world's leading fish farming group.

Much more is needed, though, if cod farming is help redress the decline in the wild population. Globally, the wild catch has plunged to about 1 million tonnes a year from 4 million in the 1960s. Stocks in northern waters, especially the Barents Sea, remain strong, but the World Wildlife Federation and others warn that overfishing is changing that.

Experts say it will be a long time before farmed cod production rivals the wild catch. "I don't think at this stage we are anywhere close to that," said Barrie Deas, chief executive of the Britain's National Federation of Fishermen's Organisations (NFFO).

Farmed cod will also be hard pressed to match the popularity of farmed salmon, more than one million tonnes of which were consumed last year, say aquaculture analysts at Norway's Kontali Analyze.

Salmon is better suited to aquaculture and its distinctive pink hue offers a marketing advantage over cod's white anonymity, Kontali Analyze noted.

TRULY SUSTAINABLE?

For now, attracting more attention than production figures is Johnson's claim that it is raising the world's first organic, sustainable cod.

One staunch opponent of the aquaculture industry is Bruce Sandison, chairman of the Salmon Farm Protest Group, based in Scotland. Barely pausing for breath, he reels off a list of problems: diseases have spread in crowded sea pens; farmed fish have escaped and damaged wild stocks; the farmed product is less healthful for consumers.

"The same thing is going to happen with cod," he said, pointing out that a disease called Francisella decimated about half the cod in a Norwegian fish farm in 2005.

"What we're playing with here is a wild species that has existed on the planet since probably the end of the last ice age. We're pushing that toward extinction, and we're going to replace it with a totally artificial species."

Questions have also been raised about the sustainability of fish farming. It takes a huge cull of smaller wild fish, about four tonnes worth, to feed every single ton of the captive population.

The Shetland farm has found a way around this problem. All its cod are fed with the "off-cuts" -- scraps destined to be discarded -- of wild fish already caught for human consumption.

"I doubt if that would be practical if the kind of expansion that is envisaged takes place," said Deas of Britain's National Federation of Fishermen's Organisations.

Aware of this limitation, researchers are beginning to consider alternative food sources, raising a distant prospect of truly sustainable fish farming. And if organic farms are also successful in curtailing harm to the broader environment, aquaculture could win over more of its critics.

"There would not be a lot left for us to moan about," said Tom Pickerell, a fisheries policy officer at the World Wildlife Fund-UK.

FROM SEA PEN TO TABLE

In the meantime, Johnson's Shetland cod has been able to lure a growing number of customers. Sold under the No Catch brand name, it is available in hundreds of Tesco and Sainsbury's supermarkets across Britain.

"It allows people to enjoy cod but without having any sort of guilty conscience about where that cod is coming from," said Joanna Keohane, spokeswoman for Tesco.

The avoidance of guilt is clearly a powerful influence in some markets: British shoppers are happy to pay a premium for the farmed cod over its wild brethren.

Copyright © 2007 Reuters, All Rights Reserved.

Common Carp

2007-02-06T16:15:00.000-08:00

Notes from Fundamentals of Aquaculture, James W. Avault, Jr., Ph.D., pgs. 86-93

The common carp (Cyprinus carpio) is the longest and most widespread cultured finfish.

Common carp (Cyprinus carpio)
From Амурский сазан, Vertebrata
The common carp has been cultivated for 2400 years in China and 1900 years in Japan and widely distributed throughout the world. The common carp is farmed as far north in freezing regions such as the former Soviet Union and as far south as the Phillippines where it is cultivated in rice fields. In Austria, the Christmas carp is an important tradition and in many Asian countries carp serves as an important source of animal protein.

In 1965, Carp was recorded to have contributed 231,525 tons to the world fish supply, which excludes production in China which would exceed all combined figures. In all a total of 1.65 million tons of common and Chinese carp was grown there in 1965, but the last estimate could be half too low.

Through selective breeding, strains of carp have been developed over the centuries, including the leather carp and mirror carp. These two strains have remained in use, while others discarded. Carp breeding has continued around the world, with the mirror carp strain, now referred to as the "Israeli carp".

In China, a fully scaled strain of common carp, known as the big-belly carp, evolved, withstanding harsh environment of overcrowding and poor water quality. This fish strain is one of the few culture species which is considered truly domesticated.

The common carp was introduced in the United States in 1877, and is found today in 48 states. Though this species is prized in Europe and Asia, it has been considered by some to be a pest because it muddies water while foraging, intereferes with sportfish such as largemouth bass and the flesh contains numerous small bones. Some states have developed programs to regulate carp populations in reservoirs. Carp usually spawn in beds of weeds along shorelines, with the adhesive eggs sticking to vegetation, so one effective control method is by lowering the water level and stranding eggs after spawning.

Common carps are hardy, fast-growing and tolerant under adverse conditions with a prolific reproducers in captivity. The carp is a freshwater fish, but can tolerate up to 20 ppt salinity, and alkaline (acid water), not bothered by turbid water and grows on a variety of feeds including agricultural byproducts. Its biology and reproduction are well known making it easily farmed in a variety of culture systems. One expirament conducted by Szumiec (Poland, 1979) reported on common carp farming, with goal of producing 2.2 lb or larger. Stocking rates varied from 121-4047 per acre. Feeds included pellets and dough containing 25% protein derived mostly from plant origin, wheat used as a comparable carbohydrate feed and super pellets which contained 40% protein (primarily animal origin). The study lasted from April until the end of September and repeated for four years. Some fish reached as much as 3 lbs, and it was concluded ponds can produce 1786-2679 lbs per acre of carp with carbohydrate feeds, and 2679-5358 per acre with protein-rich pellets.

NOAA 2008 Budget Request

2007-02-06T07:29:00.000-08:00

NOAA ANNOUNCES 2008 BUDGET REQUEST

Feb. 5, 2007 — Retired Navy Vice Adm. Conrad C. Lautenbacher, Ph.D., undersecretary of commerce for oceans and atmosphere and NOAA administrator, today announced highlights of President Bush's proposed 2008 budget for the Commerce Department's National Oceanic and Atmospheric Administration. Lautenbacher said NOAA's request totals $3.8 billion or an increase of 3.4 percent over the administration's 2007 request.

"The President's budget makes a substantial investment in our oceans that will pay dividends for years to come," said Lautenbacher. "We will be able to make great progress in the goals laid out in the President's Ocean Action Plan of ensuring sustainable use of ocean resources, protecting and restoring marine and coastal areas and enhancing ocean science and research."

Sustainable use of ocean resources + $25 million:
- Establish the regulatory framework for environmentally sustainable commercial aquaculture opportunities.
- Improvements for better management of aquaculture harvests.
- Support of the new and expanded requirements of the Magnuson-Stevens Management Reauthorization Act of 2006.
- Additional funding for observer programs and market-based approaches to fisheries management.

News Audio (mp3)
NOAA Administrator Conrad Lautenbacher media teleconference briefing in Silver Spring, Md., on NOAA 2008 budget request.

Support for the President's U.S. Ocean Action Plan

- Protection and restoration of marine and coastal areas + $38 million
- Enforcement and management of the newly designated Northwestern Hawaiian Islands Marine National Monument.
- Funding to restore nearly 1,000 stream miles for endangered Atlantic salmon and other species.
- Klamath River salmon recovery.
- Competitive grant programs focused on the Gulf of Mexico Alliance coastal resource priorities.

Climate Monitoring and Research

- Support for the National Integrated Drought Information System +$4.4 million.
- Support for the U.S. Integrated Earth Observation System +$0.9 million.
- Research to understand the link between ocean currents and rapid climate change +$5 million.
- Enhance computational support for assessing abrupt climate change +$1.0 million.

Read the Entire Story at NOAA News Online

Aquaculture in South Africa - Farming Endangered Abalone

2007-02-06T07:19:00.000-08:00

'Abalone farming has the highest economic value as compared to all other farmed products'

Known in South Africa as "perlemoen", abalone is so endangered the government has drastically reduced the total allowable catch in the wild and attempted to encourage saltwater farming of the curlicue-shaped shellfish.
Resembling a giant limpet and a distant relative of garden snails, it thrives only in oceans or special land-based farms that use seawater to cultivate the creatures.

'The amount of illegal abalone confiscated in South Africa has skyrocketed'
Abalone's growing popularity in Asia, where it is a status symbol and reputed aphrodisiac, has spurred sophisticated smuggling rings, some linked to China's notorious Triad gangs, according to South Africa's Institute of Security Studies.

The amount of illegal abalone confiscated in South Africa has skyrocketed to more than a million shellfish from a mere 21 000 in 1994. It is now common for police to pull over trucks, sometimes refrigerated, carrying illegal abalone on the roads of the Western Cape and Eastern Cape, where most of the delicacy is harvested. "We've had good successes, especially towards the end of 2006, where we seized huge quantities of abalone - this is just the tip of the iceberg," said Captain Billy Jones, a spokesperson for the Western Cape provincial police. But legitimate businesses also see a future in abalone farming in South Africa. 'Abalone farming has the highest economic value as compared to all other farmed products'
Production accounts for 60 percent of the country's aqua-culture revenues. In 2006 it was worth more than R141-million and employed about 800 people.

"Abalone farming has the highest economic value as compared to all other farmed products and is the highest employer within the marine aquaculture sector," said Blessing Manale, spokesperson for South Africa's department of environmental affairs. He said the department hoped job losses in shrinking abalone fishery could be offset in the burgeoning farm-raised sector, which in 2006 produced more than 900 tons of abalone and is projected to hit the 1 000 ton mark in 2007.

Read the entire article SA caters to Asia's craving for 'perlemoen', News for South Africa (February 06 2007 at 11:44AM)

Minnows and other Bait Fish

2007-02-05T07:20:00.000-08:00

Notes from Fundamentals of Aquaculture, James W. Avault, Jr., Ph.D., pgs. 81-83

Minnows and Other Baitfish
Commerical production of bait minnows was worth more than $100 million in 1983 (Dupree and Huner 1984). Arkansas accounts for about half of the U.S. supply and in 1982 had fifty six acres in minnow production (National Aquaculture Development Plan, 1983). In 1980, Minnesota had 731 farms totalling sixteen thousand acreas.
Kansas, Louisiana, Mississippi and Missouri had more than 1000 acres devoted to baitfish culture. Minnow production has averaged about 600 lbs per acre and net profit about $200 acre. (National Aquaculture Development Plan, 1983). Of about 100 species of sportfishing bait commonly used in the U.S., only four are used in quantity:
1. golden shiner (Notemigonus crysoleucas)
2. fathead minnow (Pimephales promelas)
3. white sucker (Catostomus commersoni)
4. goldfish (Carassius autatus)

Golden shiner

Golden Shiner (Notemigonus crysoleucas)
Based on image at Minnow Family, Cyprinidae
This fish gets its name from appearance of gold flashing, is principally cultured in the mid-South. One strain with orange or red fins has a nervous temperament and jumps from bait containers. An ovarian protozoan parasite (Plistophora ovariae) is a problem, but selecting young broodstock (about 1 year old) helps avoid the parasite. This species reaches sexual maturity at one year, when it is about 2.5 inches in length. Each female can spawn up to 10,000 eggs when temperatures reach 70°F. Spawning mats are used to collect their adhesive eggs and then placed into nursery ponds to hatch.
In growout ponds, stocking rates vary from between 50,000-200,000 per acre. With feeding, production ranges from 600 to 800 lbs/acre. At harvest fish are graded to size. 6.4 cm or less is considered small and used for crappie (Pomoxis spp.) bait. Larger sizes which range up to 10 inches, are used for baiting largemouth bass and catfish on trotlines.

Fathead Minnows

Fathead Minnow (Pimephales promelas)
Based on image at Minnow Family, Cyprinidae
Cylindrical and seldom grows larger than three inches. Principally raised in Minnesota, the Dakotas and Arkansas. Reaches sexual maturity at one year and spawning begins when water temperature reaches 65°F. Females lay between 200 to 500 eggs each spawn. One female reportedly produced 4000 eggs from 12 spawns during eleven weeks. Eggs are attached to substrate debris. Fry are stocked at 50,000 - 300,000 per acre in growout ponds. Some catfish farmers stock broodponds with adult fathead minnows at 2000/acre which provides winter forage.

White Sucker

White Sucker (Catostomus commersoni)
Based on image by Joseph Tomelleri Minnow Family, Cyprinidae
This species is native to the east of the Rocky Mountains from southern Canada, south to Colorado, Missouri and Georgia. Principally it is produced for bait in the upper Midwest, for crappie, muskellunge (Esox masquinongy), yellow perch (Perca flavescens) and northern pike (Esox lucius).

Goldfish

Goldfish (Carassius autatus)
Based on image at Minnow Family, Cyprinidae
Goldfish, well known as an aquarium fish with its color variations, is also cultivated as a bait fish. It begins spawning at 61°F, and a female may lay anywhere between 2000-4000 eggs over a period of several spawns. Goldfish are cultured in many ways similar to the golden shiner, but not as widely accepted for bait because it is sluggish. However, it is hardy and makes a good trotline bait. Goldfish are also grown to feed tropical carnivorous fish.

Other Baitfish
The bull minnow (Fundulus grandis) is used along the Gulf of Mexico for saltwater sportfishing. Suppliers of live bait rely almost completely on wild fish. Other bait fish are the top minnows (Poecilia vittata and P. mexicana) as bait for skip jack tuna (Katsuwonus pelamis). Tilapia have also been used as baitfish with both fresh and salt sportfish.

Minnow farming has good potential, but markets must be carefully studied and the existing competition with artificial bait. Farmers should determine market demand and seek to fill a niche, rather than produce a product then seeking a market. The most viable market with bait minnows is use for saltwater sportfishing. The downside is that minnow culture is capital intensive and more labor is required than with other types of aquaculture due to grading and extra effort required in shipping.

Aquaculture in Public Schools

2007-02-03T23:51:00.000-08:00

Farm living requires far greater cultivation
By Erin Elaine Mosely
Montgomery Advertiser
WETUMPKA -- Agriculture classes are part of the fabric of America, a nation built on farming and producing raw goods. But over the years, agriculture classes in high schools have given way to new studies collectively known as agriscience.

"It's not teaching cows, plows and saddles," said Jacob Davis, executive secretary for the Alabama Future Farmers Association. "It's teaching the concept of forestry management or aquaculture and how to manage a fish pond or fishery."

Growing up in a small town doesn't necessarily mean kids know about agriculture.

"A lot of kids don't grow up around animals, so (learning about agriscience) opens their eyes to something different," said Michael Hutto, an agriscience teacher at Wetumpka High School.

Billingsley High School will open a 1,500-square-foot aquatic center this summer. It will be one of only two schools in the tri-county area and one of just 40 in the state with facilities to raise fish.

Teacher Clayton Spencer said the new aquatic center, which will house tanks for raising tilapia, isn't just for agriscience students.

"Every part of the curriculum can use it -- math, science, social studies and English," he said.

"You can teach math because it's hands-on. You can take fish out and weigh them on Monday and take them out and weigh them again a week later. You see the percentage of weight increase. That's not just numbers in a book."

Joe Brown, a teacher at Wetumpka High School, said the curriculum and demographics have varied since he started teaching 30 years ago.

"We have changed an awful lot," Brown said. "Horticulture still has a lot of interest here, but our program has diversified. We have building construction, animal science, floral design, aquaculture and fish and wildlife."

Read the article in its entirety

Aquaculture Operations

2007-02-03T23:33:00.000-08:00

Aquaculture oversight pushed
By Sean Hao, Advertiser Staff Writer

The United States needs to better regulate aquaculture operations, which are expected to grow fivefold into more than a $5 billion industry by 2025, according to a report released yesterday.

At present, the aquaculture industry, which includes 70 Hawai'i operations, provides about half of all seafood consumed in the United States. However, the nation's growing reliance on ocean farming operations will require new standards and practices to ensure protection of marine ecosystems, according to the Marine Aquaculture Task Force, a group of researchers, educators and aquaculture operators.

"In just a few years, most of the seafood we consume will come from aquaculture," said task force member Daniel Benetti, an associate professor and the director of aquaculture at the University of Miami. "The question is not whether we should endorse it. The question is how and where we should do it."

Read the entire article.

NOAA Aquaculture Program

2007-02-03T23:20:00.000-08:00

The National Oceanic and Atmospheric Administration has released a draft 10-Year Plan for the NOAA Aquaculture Program. Through adoption of this plan, NOAA seeks to establish an improved system for regulating and monitoring U.S. marine aquaculture, develop new seafood farming technology, improve public education about aquaculture, and influence development and adoption of global sustainable aquaculture practices and standards. The plan is available for public comment until November 30.

NOAA developed the plan at the request of the Department of Commerce’s marine fisheries advisory committee, made up of a diverse cross-section of public representatives. The plan identifies the program’s goals and strategies, budget and staffing requirements, and potential outcomes, benefits and challenges through 2017. The public is asked to provide overall comments on the adequacy and appropriateness of the plan as well as offering specific recommendations for improvement.

“A strong marine aquaculture industry will benefit America’s coastal communities with new jobs and revenues, and secure the availability of our nation’s future seafood supply,” said Bill Hogarth, director of NOAA Fisheries Service. “This plan provides a promising roadmap for how we will achieve our ambitious goal of increasing sustainable U.S. production of farmed seafood and meet the stock enhancement needs of the nation’s commercial and recreational fisheries over the next 10 years, while providing environmental and other safeguards to protect wild stocks and marine ecosystems.”

The United States imports almost 70 percent of its seafood, 40 percent of which is farmed. Hogarth said the United States wants more control over the safety, security, and environmental standards under which seafood is raised.The U.S. aquaculture industry, made up primarily of freshwater species such as catfish and tilapia, produces a fraction of global fish production. With a robust and sustainable seafood farming industry, the nation could reduce its $8 billion seafood trade deficit by relying less on imports and increasing seafood exports. Aquaculture also has the potential to substantially increase employment and business opportunities in U.S. coastal communities.

President Bush’s Ocean Action Plan called for advancing offshore aquaculture while ensuring they operate in an environmentally sustainable manner. The NOAA Aquaculture Program is focused on supporting farming of all types of marine species, for commercial food production, non-food uses, and hatcheries that will stock fish farms and enhance wild fish populations. In June 2005, the Department of Commerce forwarded legislation to Congress that would grant the Secretary of Commerce new authority to issue permits for aquaculture in federal waters. As Congress considers passage of the bill, implementation of this plan will ensure that NOAA’s Aquaculture Program is well-positioned to take on the additional responsibility.

The draft plan is available online for the public to review online
http://www.nmfs.noaa.gov/mediacenter/aquaculture/

Read article in its entirety.

Evolution of The Blue Revolution

2007-02-03T23:14:00.000-08:00

Aquaculture: The Evolution of The Blue Revolution
Barry Costa-Pierce, director, RI Sea Grant College Program

Barry Costa-Pierce, director of the Rhode Island Sea Grant College Program and Professor of Fisheries & Aquaculture at the University of Rhode Island, discusses the latest thinking in aquaculture. His specialties are in ecological design, engineering, systems and trophic ecology of aquatic food production systems in marine locations both nearshore & exposed offshore and freshwater environments. Dr. Costa-Pierce received his BA in Zoology from Drew University, his MS in zoology from the University of Vermont, and his PhD in Oceanography from the University of Hawaii.

Media available in Audio Modem Video or Broadband

Source: New England Aquarium, WGBH - Boston

Aquaculture and the Environment in Vietnam

2007-02-03T23:06:00.000-08:00

Guidelines for the environmental management of aquaculture investments in Vietnam have been recently made available by Vietnam’s Ministry of Fisheries and the World Bank. The guidelines provide an analysis of the impacts on the environment and risks associated with aquaculture development in Vietnam and guidance on better environmental management and monitoring for its future development. (Access to Guidelines).

In other recent aquaculture news, Vietnam’s National Fisheries Quality Assurance and Veterinary Directorate (Nafiqaved) apologised to the Japanese Food and Drug Administration Bureau for the chloramphenicol found in Vietnamese shrimp recently shipped to Japan. Chloramphenicol is an antibiotic that is effective against a wide variety of microorganisms. It is a banned substance in most shrimp importing countries as it is believed that it can cause aplastic anemia in humans and other adverse side effects, but it is still used in some areas to treat disease in farmed shrimp because it is exceedingly cheap. In this connection Nafiqaved announced that they would start conducting antibiotic tests on all shrimp exports on 20th December this year.

Source: South China Sea and Thanhnien News

Banks Urged To Invest In Aquaculture

2007-02-03T22:52:00.000-08:00

From Ghana General News Charles Apenyedu, Asutsuare, on Friday, February 02, 2007

THE Minister of Fisheries, Mrs Gladys Asmah, has urged financial institutions to invest in aquaculture.

She said, aquaculture is a viable economic enterprise in Ghana and the ministry will not relent in its efforts to develop and nurture it.

The minister made the call here on Wednesday when she toured the Tropo Farms, an intensive commercial fish farm with some managing directors from the banking sector.

The tour was to offer decision makers from the three banking and financial institutions the opportunity to acquaint themselves with the progress in aquaculture development in the country.

Mrs Asmah said the ministry had so far trained 329 people throughout the country in mechanised fish farming and added that the Ministry would assist them with capital and equipment to start their own fish farming ventures.

Mr Mark Amakye, managing director of Tropo Farms, said the fish farming industry in Ghana has very great potential.

Noting that the weather and climatic conditions as well as availability of water are perfect, he said such conditions are conducive for large-scale production of tilapia.

Mr Adam Sulley, Head of Corporate and Customer Relations at the Agriculture Development Bank, expressed satisfaction at the tilapia production on the farm.

Source: Charles Apenyedu, Asutsuare

Marine Aquaculture Task Force Suggests Regulating Aquaculture

2007-02-03T22:42:00.000-08:00

Woods Hole, MA -- Congress should enact legislation to ensure that strong environmental standards are in place to regulate the siting and conduct of offshore marine aquaculture, according to an independent panel of leaders from scientific, policymaking, business, and conservation institutions. At the same time, the Marine Aquaculture Task Force suggests that the federal government should provide funding and incentives for research, development, and deployment of technologies, and techniques for sustainable marine aquaculture.
Aquaculture is the farming of fish, shellfish, and aquatic plants, and it accounts for nearly one half of all seafood consumed in the world today. The industry is growing rapidly as wild fish stocks decline.

The Task Force—-organized by researchers from the Woods Hole Oceanographic Institution (WHOI), with support from The Pew Charitable Trusts and The Lenfest Foundation—-was charged with examining the risks and benefits of marine aquaculture and developing a set of national policy recommendations to guide future development of our oceans.

Members of the panel have been meeting since the summer of 2005, and they released their findings in a media conference call. View full report -- Sustainable Marine Aquaculture: Fulfilling The Promise; Managing The Risks.

“There is a growing need for seafood to feed a hungry world, but the world’s fisheries can no longer meet the demand,” said task force chairman Rear Adm. (ret.) Richard F. Pittenger, former WHOI vice president for Marine Facilities and Operations and a former Oceanographer of the Navy. “Half of our seafood comes from aquaculture, and that share is only going to grow. The federal government has proposed a fivefold increase in U.S. aquaculture production, and while we certainly agree with an increase, we believe it must be done in an environmentally responsible way.”

Read the rest of this story at Pew Charitable Trusts News Release

Demand for Seafood Likely to Pressure Aquaculture into New Developments

2007-02-03T22:32:00.000-08:00

Growing Demand for Seafood Likely to Pressure Aquaculture into New Developments

NewswireToday - /newswire/ - Palo Alto, CA, United States, 01/29/2007 - Frost & Sullivan (ti.frost.com) finds that Aquaculture - Global Developments provides a thorough examination of fish farming and aquaculture.

The last three decades have seen the aquaculture industry develop into one of the fastest growing food producing sectors in the world. The industry today is extremely diverse and contains a wide variety of systems ranging from small ponds to large-scale commercial systems. The exponential rate at which the world population is expanding is contributing toward making culture fisheries more important than ever as a reliable source of food and resources.

Frost & Sullivan (ti.frost.com) finds that Aquaculture - Global Developments provides a thorough examination of fish farming and aquaculture.

"The growth of the aquaculture industry is vital for meeting the world's growing appetite for fish and other seafood," says Frost & Sullivan Senior Research Analyst Kasturi Nadkarny. "If the aquaculture industry manages to overcome the environmental concerns and the social and economical challenges plaguing it, it could be instrumental in narrowing the widening gap between the demand and supply of seafood."

A recent report from Food and Drug Administration (FDA) reveals that by 2030, maintaining the present-day consumption levels will require an additional 40 million tons of fish. The wild fish populations will be incapable of meeting this demand, putting an onus on the aquaculture industry to boost its production to compensate for this gap in supply and demand.

On the flip side, intensive shrimp farming results in several tons of organic waste within a single shrimp-farming crop. Most of these wastes are in the form of stable organic compounds that are difficult to be broken down into simpler forms and cannot be put to use by the phytoplankton through photosynthesis. The oxidation of these compounds results in the depletion of the dissolved oxygen content in the shrimp ponds. Further, the generation of toxic metabolites such as nitrite, ammonia, methane and hydrogen sulphide makes the soil acidic, damages the gills and tails of the fish, affects their metabolism, causes blue shrimp syndrome owing to nutritional deficiency and disrupts the molting process.

"This is mainly responsible for the high mortality rates in aquaculture shrimp farming and to add to this issue, shrimp farms are always located in close proximity of each other, making it easy for diseases to spread from one farm to another and making it difficult to be controlled," explains Nadkarny. "In addition, although most nations have the scope to considerably enhance their aquaculture production for meeting the global demand for seafood, fish farmers lack sufficient technical information that is required to improve practices aimed at higher quality and yield."

Aquaculture - Global Developments is part of the Technical Insights Food and Beverages Subscription, and it gives an overview of emerging trends in the aquaculture landscape that involves key drivers, challenges, restraints, and analysis of adoption trends.

Aquaculture - Global Developments
It is OK to republish and/or LINK any newswire for any legitimate media purpose as long as you name Newswire Today and LINK as the source.
Keywords: Aquaculture, fishing, fish farming, sea food, environmental concerns, Food and Drug Administration, FDA, shrimp farming, organic waste, organic aquaculture, fish stocks, phytoplankton, photosynthesis, toxic metabolites, nitrite, ammonia, methane, hydrogen sulphide

Tilapia Culture

2007-02-03T09:01:00.000-08:00

*Great news for Culturists. Our instructor stated the following notes I've paraphrased from, were written around five years ago. Since that time in North Carolina alone, many farmers have experienced success with Tilapia culture utilizing indoor recirculating systems.

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Cichlidae
Genera
Oreochromis A. Günther,1889
Sarotherodon W. P. E. S. Rüppell, 1852
Tilapia Smith, 1840 (Tilapia, Wikipedia)

The family Cichlidae is characterized by long dorsal fins, with some varieties being brightly colored. This group includes many popular aquarium fish. Tilapia is native to Africa and Asia, but has been distributed heavily, worldwide. The tilapias are second only to carps in popularity as a finfish culture species worldwide. This group has only very limited production in the US (like carps), though interest in tilapia culture in the US is growing.

Tilapia, photographed at Brunswick Community College Aquaculture facility (North Carolina

Tilapia
Tilapias are a tropical species, which die when exposed to water temps below 55ºF. This, along with regulatory hurdles, has contributed to the lack of commercial culture in the USA.

Despite the lack of domestic production, tilapia is now the second most widely marketed cultured warmwater fish in the USA (behind channel catfish). About 85% of the filets sold in this country originate from foreign aquaculture operations.
American Tilapia Association and Marketing of Tilapia in the USA

Most domestic tilapia are produced in indoor recirculating systems, then sold to live markets. Prices of live tilapia have plummeted to as little as $0.90/lb, due to overproduction for this limited market. This price falls below the break-even price for most US producers. There has been some recovery, but prices of $1.50/lb and higher are probably gone for good.

Some producers have switched to alternative species, while others have tried to enlarge their facilities (economies of scale) utilizing improved technology to lower production cost. Marketing plans for may include processing tilapia into filets to compete with overseas producers, and emphasizing on freshness and quality.

Culture Species
There are three genera under the common name of tilapia.

Tilapia sp.
Tilapia (genus) includes three species that build nests on the substrate. Some of these species are cultured, but this genus does not include the major culture species.

Two others are Sarotherodon sp. and Oreochromis sp.
These are the mouthbrooders, the genera that brood eggs and newly hatched larvae within the mouth after eggs are laid.

Large-scale commercial culture of tilapia is limited almost exclusively to the culture of three species:
1. Oreochromis niloticus
2. Oreochromis aureus
3. Oreochromis mossambica

Of the three tilapia species with recognized aquaculture potential, the Nile tilapia, Oreochromis niloticus, is by far the most commonly used species in fish farming.
From Tilapia Farming

The genus Oreochromis includes the three major culture species:

Nile tilapia (Oreochromis nilotica)

Nile Tilapia, Oreochromis niloticus

The Nile tilapia is a native of the Nile River, North African waters and Middle East. Sometimes called St. Peter's Fish, because it is also a native of the Sea of Galilee, and thought by some to be the fish Jesus multiplied to feed the masses at the Sermon on the Mount.

The Nile tilapia is likely the most widely cultured tilapia species. This species (or a hybrid with the blue tilapia) is most often cultured in recirculating aquaculture systems in the US.

Blue tilapia (Oreochromis aurea)

Blue Tilapia, Oreochromis aurea
Based on an image at Auburn University

Blue tilapia is the second most cultured, hybridized with Oreochromis nilotica. The blue tilapia breeds at a smaller size and earlier age than Nile tilapia (2-3 months vs. 5-6 months) and is more tolerant of high salinity and low temperature than many other species.

Various hybrids of blue tilapia and other tilapia species tend to be intermediate in tolerance of low temperature and high salinity.

Blue tilapia exhibits great skill at seine avoidance. It seeks out low spots and lies on its side during seining operations.

Black tilapia or Java tilapia. (Oreochromis mossambica)

Black Tilapia, Oreochromis mossambica
Based on an image from Zoozipcode
Like blue tilapia... black tilapia spawns at an early age (2-3 months). It is also relatively tolerant of high salinity.

A hybrid between the mossambica female and nilotica male is known to be fast-growing.

Other Notable Hybrids
spirulus x aurea: hardy cross that will live and grow in full-strength seawater.
mossambica x hornorum: cross which produce offspring with red flesh, and may contribute to improved marketing in some areas of the US, such as Florida.

Developing Countries and Tilapia
Tilapia are cultured in ponds in tropical and sub-tropical developing countries throughout the world. Various species and hybrids of tilapia have been widely introduced throughout South America, Africa and Asia by US Peace Corps, US Agency for International Development (USAID), British VSO, the United Nations Food and Agriculture Organization (UNFAO) and a large number of non-government organizations.
Tilapia has become an important source of economical, but high-quality protein in places where it is needed most.

Tilapia are also produced in conjunction with hog and/or duck production in developing countries. Hog or duck pens are constructed alongside or even on stilts directly over the ponds. Waste may move directly into the ponds, providing organic fertilization spurring the production of plankton and benthic invertebrates which are hence eaten by the fish. Some tilapia will consume animal wastes directly.
See Use of organic residues in aquaculture. However, use of animal waste fertilizer is not a popular method in U.S. fish culture. The use of animal waste as a source of fertilizer or food for fish creates marketing problems, and naturally would be a source of public health concern.

Pond Production in the United States
Tilapia and its hybrids are used for forage species in ponds for largemouth bass and sometimes used as forage for catfish broodstock. Pond production of tilapia as food for human consumption is largely limited to the southern states, Florida, Texas and Southern California. Tilapia die when water temperatures fall below 55ºF, so with the exception of a few areas of the US, tilapia will not survive through the winter.

All-male tilapia or sterile hybrids are stocked in ponds to prevent breeding, which would result in overpopulation and stunting. Fingerlings are stocked during the spring in high density, which may range between 5,000-10,000 per acre. Very high production is possible in ponds (up to 10,000 lbs/acre) since tilapia are very tolerant of poor water quality associated with high daily feeding rates.

Disadvantages in Marketing Tilapia
Nearly all of the fish are harvested within a short period in late fall before water temperatures reach lethal levels. Processors and other buyers prefer a steady, year-round supply which creates a major problem with marketing. Tilapia have a tendency to pick up severe off-flavors associated with high feeding levels in ponds which also makes them difficult to market.

Tilapia Cage Culture
Tilapia have been successfully cultured in cages. There is no need for an all male population or sterile hybrids, since tilapia can not reproduce in large-mesh (1/2") cages. Eggs and milt fall through the bottom of the cage and are not picked up by mouth-brooders. In the US, these problems are increasingly being addressed by using tank culture methods in indoor, temperature-controlled water recirculation systems.

Recirculating Aquaculture Systems
"Tank Culture of Tilapia"
There have been substantial attempts to produce tilapia in indoor recirculating aquaculture systems, both in experimental settings and on a commercial scale by private industry. While tilapia production in these systems is technically feasible, most of the attempts at commercial production have been unprofitable and have failed. However, there are some success stories using this technology, and new ventures have arose in lieu of business failures. Many newer enterprises are attempting to avoid the pitfalls discovered during earlier attempts and some show promise, but for the time no established procedures exist for commercial tilapia culture. Eventually, with continued improvements, recirculating aquaculture systems may become a more visible segment in commercial industry.

Stocking rates in recirculating system tanks are planned as to limit the total number of lbs. of fish per gallon of water, thus the total amount of feed added each day. Most commercial systems limit fish to holding capacity (feeding rate of 2% of body weight/day) that ranges from 0.25 lbs/gallon to 0.8 lbs/gallon for tilapia. Tilapia can be stocked at such high density because they are generally tolerant of poor water quality. Attempts to grow other species at such high density, such as hybrid striped bass have shown little success.

Tilapia are able to withstand low DO concentrations coupled with high ammonia levels for varying periods of time (which also depends on temperature, pH, etc.) Generally, tilapia are more tolerant of such conditions than most cultured species. Since such conditions are encountered for short periods of time in recirculating systems, tilapia are an ideal species for this type of production.

Interest has developed in commercial recirculating systems for tilapia due to year-round temperature control, lack of off-flavor problems, and demand for live tilapia in large cities in the Northeast, Midwest and West Coast. For continued growth of tilapia production in recirculating systems, producers must find ways to compete effectively in fresh dressed and frozen tilapia. This places them in direct competition with commercial producers overseas, where production costs with ponds are far lower than production costs of U.S. recirculating systems. Domestic tilapia producers face competition from cheap foreign imports, which are similar to the problems faced by many other domestic manufacturers.

World's Leading Source of Protein - Fish Products

2007-02-02T19:00:00.000-08:00

This past week it was mentioned during class the world's main source of protein comes from fish products, and a significant percentage of that, comes from Aquaculture. Some interesting Protein, Fish and Aquaculture statistics on Google.

Advancing international cooperation for sustainable fishing, improved livelihoods and fair trade policies
Fish is the fastest growing source of food in developing countries. It is the primary source of animal protein for about one-sixth of the world's population -- and often the only source of protein for millions of the world's poor. Fishers in developing countries are among the poorest of the poor and fishing is often the only way out of poverty and malnutrition for them.
Meanwhile, across the world, demand for fish has doubled in the last 50 years, and production would have to double again in the next 25 years to keep up with population growth. The number of people in the world increases every year by 80-90 million, most of them in developing countries. Demand, which has risen at twice the rate of human population growth since 1961, has greatly exceeded supply and the problem is growing.
However, the world's fisheries are in crisis -- the result of unsustainable fishing practices. The problem is huge. More than 25 per cent of the world's fisheries are overexploited, 50 per cent are being fished to their full capacity and 75 per cent need immediate action to freeze or reduce fishing to ensure future supplies. World fishery production is now more than six times that of 1950.
Continued overfishing threatens global food security, impoverishes coastal communities and degrades ecosystems. It also threatens the economies of developing countries, for many of which fish are one of their few exports and foreign currency earner. Over 70 per cent of all fish exports are sourced from developing countries and this proportion is rising.
worldfishcenter.org

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Protein: Moving Closer to Center Stage
Until recently, protein got little attention. Like a quiet child in a classroom of rowdies, it was often overshadowed by fat, carbohydrates, and vitamins. That's changing. Lately there's been an explosion of interest in protein, largely triggered by high-protein diets for weight loss.

Surprisingly little is known about protein and health. We know that adults need a minimum of 1 gram of protein for every kilogram of body weight per day to keep from slowly breaking down their own tissues. That's about 9 grams of protein for every 20 pounds. Beyond that, there's relatively little solid information on the ideal amount of protein in the diet, a healthy target for calories contributed by protein, or the best kinds of protein.

Around the world, millions of people don't get enough protein. Protein malnutrition leads to the condition known as kwashiorkor. Lack of protein can cause growth failure, loss of muscle mass, decreased immunity, weakening of the heart and respiratory system, and death.
Harvard University

--------------

State of World Fisheries and Aquaculture 2002
Of the estimated 89 million tonnes of fish produced in 2000 in the world, excluding China, nearly 71 percent (63 million tonnes) was used for direct human consumption.

Fish consumption
The total food fish supply for the world, excluding China, has been growing at a rate of about 2.4 percent per annum since 1961, while the population has been expanding at 1.8 percent per annum. Since the late 1980s, however, population growth outside China has occasionally outpaced the growth of total food fish supply, resulting in a decrease in per capita fish supply from 14.6 kg in 1987 to 13.1 kg in 2000 (Figure 2). For China, the corresponding annual increases are 6.4 percent for food fish supply since 1961 and 1.7 percent for the population (Figure 9). Annual growth was steady until the mid-1980s (at 3.8 percent from 1961 to 1985) and then suddenly trebled over the following 15 years (10.8 percent from 1985 to 2000).
Source: FAO.org

Sodium Thiosulphate

2007-02-02T09:30:00.000-08:00

Water companies began adding Chloromites to tap water which is poison to fish. Sodium thiosulphate is used to get rid of Chloromites in tap water.

Sodium thiosulphate
Chloramine==Ammonia?

Use a standard sodium thiosulfate declorinator for both chlorine and chloramine. However, for chloramine use it double strength. Some (and I am being cagey here) products designated to neutralize chloramine are known by their manufacturers to be toxic to fish at concentrations higher than that recommended on the bottle. ie, you have to be fairly precise. The old standard however is very forgiving. No one advertises this as it is likely to hurt sales. Moderate plant growth will take care of any excess ammonia released by the application of sodium thiosulfate to chloramine.
Declorinators (like thiosulfate) will break the chlorine + ammonia bond and set the ammonia free (so as I am told). This replaces toxic choraimine with potentially toxic ammonia. Now, extra thiosulfate will handle the free clorine. So, that leaves the ammonia...

The concentration of the released ammonia will be related to the concentration of the original chloramine. The resultant ammonia concentration is something similar to the chloramine concentration. So, I think we are talking about 1 to 2 ppm (mg/l) of ammonia (to be diluted according to the % water change). For 50 % change you can have 1 ppm of ammonia. The amount of this that is toxic to fish will depend mostly on pH but also on temperature. (There is an equilibrium between toxic NH3 and non-toxic NH4). Worst case is high pH and high temperature. At 8.5 pH and 86 deg, 20 percent would be toxic NH3 (~ 0.2 ppm). This is a lot and roughly corresponds to lethal dose for 1-hr exposure.
• Ideally fish should be diagnosed by an authorised or qualified technician.
• Carefully calculate dose rates according to manufacturers label.
• Remember that some chemicals may not be approved for use with fish that are for human consumption.

Biological vs Mechanical Filters

2007-02-02T08:01:00.000-08:00

Here's something interesting I learned this week in Aquaculture Practicum, from John (BCC Instructor).

A biological filter contains bacteria which convert ammonia to nitrite and nitrobactor converts nitrite into nitrate. Nitrate is plant fertilizer, which is much less toxic than nitrite.

Ammonia occurs naturally in the environment. A small amount of ammonia is generated when lightning strikes and reaches earth in rainfall. But most ammonia is produced by bacteria in water and soil as an end product of plant and animal waste decomposition. It is found in relatively low nontoxic concentrations in soil, air, and water and provides a source of nitrogen for plants.
In soils and water ammonia will go through many complex biochemical transformations. These transformations constitute what is commonly known as the nitrogen cycle.
Ammonia in Water
Water reacts with ammonia to form ammonium and hydroxide ions. Ammonia is often referred to as “unionized ammonia”. Ammonia is toxic to aquatic organisms but ammonium is non-toxic. There exists an equilibrium in water between the toxic ammonia and the non-toxic ammonium. The equation shifts back and forth depending upon existing or introduced environmental changes.
NH3 (aq) + H2O (l) NH3 · H2O (aq) NH4 + (aq) + OH - (aq)
(Ammonia in water) (ammonia+water) (ammonium + hydroxide ions)
The dynamic equilibrium between NH3 and NH4 + is affected by water temperature and pH (acidity). At a pH of six the ratio of ammonia to ammonium is 1 to 3000 but decreases to 1 to 30 when the pH rises to eight (becomes less acidic). Warm water will contain more toxic ammonia then cooler water. When sampling water for ammonia analysis both the temperature and the pH of the surface water body must be measured at the same time the water samples are collected. (See “Ammonia, pH and Temperature Calculator”)
If ammonia is directly spilled into surface water or if water used by a fire department to depress an ammonia vapor cloud is allowed to reach surface water, aquatic life can be harmed. Even at a concentration of 0.02 mg/L (48 hour LC50) unionized ammonia is lethal to some sensitive freshwater fish. That equates to about ½ a cup of unionized ammonia in one million gallons of water. Ammonia is also highly toxic to freshwater invertebrates having a 48-hour LC50 of 0.66 mg/L for Daphnia magna . Again, water contaminated with fertilizer ammonia should not be allowed to enter any storm drains, rivers, drainage ditches, wetlands or lakes.
From Ecological Effects of Ammonia

A mechanical filter stops all solids.

Biological Filters

John explains this is both a biological and mechanical filter

Biological Filter

Mechanical Filter
From What Is A "Biological Filter"?
By Stan and Debbie Hauter
Your Guide to Saltwater Aquariums.
The biological filter in a saltwater aquarium is nothing more than a place for bacteria to grow. Any surface in an aquarium which comes in contact with tank water and the nitrobacter & nitrosomona bacteria species that you created when you cycled the tank is part of your bilogical filter. The velocity of the water passing over the bacteria also affects the efficiency of the biological. The faster the water moves over the bacteria, the more efficient it is, up to the point where the bacteria is being stripped from the filter surface.
The efficiency (strength) of a biological filter is determined by its surface area and the amount of water passing over it. Some filter medium are more efficient than others. Aquarium glass surface area aside, here are the most popular biological filtration methods:

Canister Style Filters come in many different styles and sizes and can also be multifunctional.
Live Rock / Berlin Systems are the filters of choice for many SW aquarium purists.
Live Sand / Jaubert Systems are also very popular with many reef aquarists.
Undergravel Filters are among the first biological filters created for SW aquarium hobbyists.
Wet / Dry Trickle Filters were the next step after the UGF to dramatically improve efficiency.
Biological Filtration Polls show you which biological filters are popular with other habbyists.
Choosing Your Biological Filter Material shows you which materials are more efficient.
Knowing how each biological filter works and what it requires will make Choosing a Filtration System In 5 Easy Steps much easier.

Lowering pH Levels in Water

2007-02-02T06:51:00.000-08:00

As a follow-up to my earlier post, on pH levels and water

Water samples which indicate a high pH level when tested, could be adjusted by straining water through peat. The instructor at BCC compared it to "tea," which is dark, but safe for fish. Added to the aquarium, the pH level was brought down within a safe range.

Here's John straining the brackish water.

Large debris are removed by hand, then strained through a fine net tightened down with a bungee cord (pulley) on a large bucket.

Brackish water, (low pH solution added to one of the empty tanks). John (instructor of Aquaculture Practicum at BCC) warned it wouldn't be good for fish to be swimming in their tank and suddenly the pH drops an entire point, so the transition is accomplished gradually.

2007 NC Aquaculture Development Conference

2007-02-01T19:18:00.000-08:00

2007 NC Aquaculture Development Conference
http://www.ncaquaculture.org/2007agenda.html
http://www.ncagr.com/aquacult/
Annual Meeting Planned in conjunction with the 2007 NC Aquaculture Development Conference Feb 9-10 2006.
The North Carolina Aquaculture Association is a private non-profit corporation formed in 1991. Its purposes are to provide support through promotion, marketing, and other beneficial acts to strengthen, expand, and diversify the industries of freshwater and marineaquaculture in North Carolina
Subject to prior approval, the Association may take a position and press an opinion on issues directly and generally affecting the aquaculture industry.
http://www.agr.state.nc.us/aquacult/NCAA.html

Friday Feb. 9, 2007
8:00 Registration and Trade Show open

9:00 Introduction and Welcome
Michael Twiddy, NCSBTDC

9:15 State, National, and International Overview
Dr. Tom Losordo NCSU

9:45 State Aquaculture Research Update.
Dr. Craig Sullivan, Professor, NCSU
Dr. Wade Watanabe, Research Professor UNCW

10:15 Break- Visit our Trade Show

10:45 The Latest Developments in Pond Aquaculture
Dr. Les Torrans-USDA-ARS, Stoneville MS

11:10 Coastal NC Aquaculture Effluent Challenges
Dr. Harry Daniels-NCSU

11:30 The NC Agricultural Cost Share Program and Aquaculture
Natalie Jones

11:45 Break-Visit the Trade Show

12:00 Lunch

1:00 Keynote Speaker: Dick Jones, Seafood Purchaser, HEB "The Future of Aquaculture in the Retail Sector"

1:30 Break-Visit the Trade Show

2:00 The Future Role of Sea Grant in Aquaculture- Dr. Michael Voiland

2:30 Update on Prawn Culture
Mike Frinsko- NC Cooperative Extension

2:45 Break-Visit the Trade Show

3:15 National Aquatic Animal Health Update
Dr. Gary Egrie - USDA APHIS

3:35 Cormorants and Bird Control on Fish Farms
Greg Ellis - USDA/APHIS/Wildlife Services

3:55 North Carolina Oyster Hatchery Program
Joanne Harcke- NC Aquarium

4:15 NC Marine Fisheries View of Commercial Aquacutlure
Craig Hardy- NCDMF

4:30 Adjourn

4:45 NC Aquaculture Association Meeting

6:00 Social

6:30-9:30 Aquafood Festival

Saturday Feb. 10, 2007 Concurrent Workshops

Refinements in Pond Aquaculture
9:00-10:30 Dr. Les Torrans
National Warmwater Aquaculture Center
Stoneville, Miss.

Shellfish and Marine Aquaculture
9:00 North Carolina's Oyster Hatchery Program.
Jo Anne Harcke, N.C. Aquarium

9:30 North Carolina's Oyster Gardening Program. John Allison and John Zimmerman, Shellfish Gardeners of North Carolina

10:00 Remote Setting of Oysters.
Jim Swartzenberg, J&B Aquafood

10:30 Developments in Culture of Black Sea Bass in North Carolina.
Troy Rezek. UNCW

11:00 Non-Typical Culture Potential: Bryozoans. Dr. Niels Lindquist, University of North Carolina Institute of Marine Sciences

Startup Guide to Aquaculture
Presented by Mike Frinsko, Steve Gabel, and Matt Parker
8:00 Hybrid Striped Bass Culture

8:45 Catfish Production

9:30 Break

9:45 Freshwater Prawn Production

10:30 Crawfish Production

Saturday Industry Tour*
Tour #1- Circle-G Farms -Tilapia Barn, Saulston NC
- DJ&W Shrimp Farm- Kenly NC
Tour #2- Castle Hayne Fisheries, Hybrid Bass, Aurora, NC
- One Fish Two Fish Catfish Farm. Chocowinity NC

*Maps and more information about the tours will be provided in conference registration packets

Registration
http://www.acteva.com/go/ncaquaculture
Full Conference Registration Late
Price: $125.00 Processing: $0.00 Total: $125.00

Full Student Registration
Includes Aquafood Festival, Must show valid ID
Price: $45.00 Processing: $0.00 Total: $45.00

Preconference Recirc Workshop Only
Price: $225.00 Processing: $0.00 Total: $225.00

Student Preconference Recric Workshop
Price: $125.00 Processing: $0.00 Total: $125.00

Preconference Recirc Workshop AND Full Conference Registration
Price: $250.00 Processing: $0.00 Total: $250.00

Student Preconference Recric Workshop and Full Conference Registration
Price: $170.00 Processing: $0.00 Total: $170.00

Trade Show Booth
Includes One Full Conference Registration
Price: $275.00 Processing: $0.00 Total: $275.00

Conference Presentations Only
Does NOT include Aquafood Festival
Price: $75.00 Processing: $0.00 Total: $75.00

Aquafood Festival Only
Price: $35.00 Processing: $0.00 Total: $35.00

Pond Construction

2007-02-01T18:38:00.000-08:00

These shots were of the ponds out back of the Brunswick Community College Aquaculture Center, unfortunately none developed too well. Obviously, the settings on my camera were wrong. I use a Canon PowerShot S3 IS Digital Camera which normally captures high resolution, widescreen images with great color, but not this particular day. I'll try in the next days to capture some color corrected shots of the BCC ponds. I felt this is important, regarding my last post on Aquaculture Myths, such as the realities "Running a fish farm requires hard physical work and can be stressful," "Farming is the best background for getting into fish farming. Basic farming skills like operating a tractor, equipment repair, and welding are needed," and soforth.
The size of land to accomodate such ponds and the labor involved is intensive and insight into what's involved with an Aquaculture operation. Dr. Holland (BCC) expressed a bit of humor with the people who presume they'll build (and/or start) a fish farm in their backyard. It simply doesn't work that way as you can see from these shots.

Here are the better photographs, as promised!

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Myths about Aquaculture

2007-01-30T19:34:00.000-08:00

Today, I picked up a few grocery items at the supermarket (I should mention I took notice of the Tilapia filets in the freezer section while shopping, which was a first), but when checking out, the issue arose I was back in college. I've known Pat for around 20 years, and she asks, "You're back in college?" "Yes," I replied, "I'm going there for Aquaculture." "Did you say Agriculture?," with a little bit of confusion. I laughed a bit, "Aqua culture. It's a little like Agriculture, except you farm fish." "So, when you finish, you're going to build a fish farm?" To which I replied, "No, actually I'm hoping to go on to UNCW for the Marine Science program."

MYTHS
So far, I've personally acquainted a small number of people, who either simply do not know what Aquaculture is, or perpetuating spreading myths about it. For instance, one lady I spoke with, told of a young girl attending the Aquaculture program, who "spent so much time in the water, she became sick of it, and had to change her major." This, simply is not true. I was also advised to get a diving suit.

I chuckle, and wonder what will I will hear next.

Not a myth: Far more alarming are the facts of big fish being fished out, dead zones in the oceans and seas from fertilizer run offs ... coral reefs dying, rain forests being cut down, levels of mercury in nature and other pollutants seeping into the ground water (even toxins in discarded electronic devices seeping into the ground water, and leaky Super Fund sites that will cost billions to clean up), none of which is in dispute. (Edward T. Babinski warning of fish, in shortage).

The growing Aquaculture industry may provide a sound mean to feed the world in the near future, without posing a threat to the environment.

Here's some information from the web, on further Aquaculture myths (which incidentally, seem to coincide with the warnings Dr. Holland has given our class at BCC) .. concerning the realities of success in Aquaculture. I will highlight those points:

In the course of working with hundreds of people interested in starting aquaculture enterprises, the author has arrived at two pieces of advice that he would like to pass along to you now:
1. Imitation, not innovation, is the key to success for beginning aquaculturists. A proven species and type of production facility is almost always the best choice. Few new fish farmers can afford the time or money needed for experimental systems.
2. Start small and learn as you grow. No matter how well you plan your aquaculture enterprise, you will learn a great deal during your first few years of operation. Starting small will allow you the flexibility to improve your facilities and time to develop your markets while minimizing your risk.

Some common myths about aquaculture

Fiction: Any fish or aquatic animal can be economically raised on a fish farm.
Fact: Most cannot be. Lack of control over reproduction and nutrition, make the farming of many desirable species impractical at present.

Fiction: I can find a site for a fish farm on my property.
Fact: Most sites are unsuited for fish farming because they lack adequate water or proper soils for pond construction.

Fiction: Fish farming is relatively easy.
Fact: Fish farming is agriculture and requires close management, hard work and the ability to tolerate risk.

Fiction: Fish farming is very profitable.
Fact: As in other types of agriculture, the level of profit is seldom excessive.

Fiction: Fish farming is a good retirement activity.
Fact: Runnning a fish farm requires hard physical work and can be stressful.

Fiction: Fishing is a good background for getting into fish farming.
Fact: Farming is the best background for getting into fish farming. Basic farming skills like operating a tractor, equipment repair, and welding are needed.
From: Getting Started in Aquaculture

MORE MYTHS ON THE WEB
Myth #1: Farmed salmon is not safe to eat.

Reality: Eating farmed salmon does not pose a health risk. Claims that eating farmed salmon can cause health risks such as cancer can unnecessarily frighten people and prevent them from enjoying the benefits of eating fish. Fish and seafood are an important part of a healthy and balanced diet.

Scientific studies indicate that trace amounts of PCBs (polychlorinated biphenyls) in both farmed and wild salmon are well within acceptable limits and similar to the amounts found throughout our food supply – in beef, chicken, pork and dairy products. PCBs and other contaminants are a legacy of industrial practices that find their way into the food chain in nearly all foods.

Health Canada and the Canadian Food Inspection Agency (CFIA) work together to ensure that our food supply is safe. For example, the CFIA conducts rigorous inspections of fish processing establishments across Canada and they analyze food samples for impurities, drug residues or disease-causing agents. Health Canada sets standards and policies for the safety of food and veterinary drugs sold in Canada.

Myth #2: Farmed salmon is not as nutritious as wild salmon.
Myth #3: No one is supervising salmon farms.
Myth #4: Salmon farms are bad for the environment.
Myth #5: Left-over food and feces from salmon farms pollutes the ocean.
Myth #6: Farmed salmon are pumped full of hormones and antibiotics.

Reality: Farmed salmon are not fed or injected with growth hormones. Antibiotics, if they are required, are provided by veterinarians. Health Canada has clear rules about drug use on food animals. Maximum residue limits for each drug are set and must be met through appropriate withdrawal times following treatment before the fish can be harvested. The CFIA monitors fish at federal processing plants to ensure they do not exceed the levels set by Health Canada.

When compared to land-based farmed animal production, salmon farming uses the least amount of antibiotics. In recent years, advances in vaccine development, similar to the practice used for raising livestock, have resulted in a significant reduction of antibiotic use.

Myth #7: Farmed salmon are full of additives to make it look like wild fish.
Myth #8: Escaped, farmed salmon are killing wild salmon stocks.
Myth #9: Escaped Atlantic salmon have been mating with wild Pacific stocks.
Myth #10: Farmed salmon spread disease to wild salmon.
Myth #11: Sea lice from farmed salmon are destroying pink salmon stocks in BC.
Myth #12: Food fish are being taken away from wild stocks to feed farmed fish.
Myth #13: The Science on the aquaculture issue seems confusing.
Myth #14: DFO supports the development of "Frankenfish".
Myth #15: Only closed-containment or land-based systems should be used to farm salmon.
Myth #16: Salmon farming is a small-scale experiment and has no future in helping ensure a global source of protein or local jobs.
From Myths and Realities about Salmon Farming

Aquaculture has now become a significant competitor for space in coastal and freshwater areas. To be accepted, however, it must demonstrate convincingly that aquaculture will not jeopardize other legitimate uses of the coastal, brackish and freshwater zones through causing unacceptable changes to the environment. As the aquaculturists are among the first to suffer the consequences of environmental deterioration their concern for the environment should, of necessity, be equal to or greater than that of those wishing to preserve it for other reasons. It has been pointed out that there are many "truths and myths" concerning aquaculture and the environment. Selected examples will be used to show how particular environmental factors are involved and what have been the results, probable consequences or misconceptions. The conclusions and ultimate message is clear; aquaculture can be practised successfully and profitably without compromising the environment. For this result to be achieved, however, it is necessary for aquaculture to employ only sound farming practices which penalize neither the aquaculturist nor the environment.
From Aquaculture Canada 2000 Abstracts

Other Myths
Are you one of those people who believe that farmed fish are full of medicines, and that they are really a sort of second-class food? If so, you are quite wrong, and have been for many years. Now, scientists at the Institute of Marine Research want to put paid to some long-standing myths about conditions in Norwegian aquaculture.
by Ingrid Dreyer
Fish are healthy food, and fish farming involve good exploitation of resources in comparison with meat production in agriculture. Fish are also an extremely popular product in many parts of the world. However, many people have a negative impression about the quality of farmed fish.
“In blind tests in which people taste fish food, most people prefer farmed fish to wild fish. However, if they are told that what they are tasting is farmed fish, their opinion of its quality automatically falls”, says research director Ole J. Torrissen of the Institute of Marine Research. He has no doubt that such attitudes are a holdover from the early days of fish-farming in the eighties, when consumption of medicines was high, and environmental problems around fish farms were common. But even though several decades of research and development and the establishment of solid monitoring and management systems have got rid of most of the childhood problems of fish farming, the negative attitudes still persist.
Antibiotics scarcely used now
One of the most enduring myths is that farmed fish are full of medicines.
“Many people believe that Norwegian fish farming still uses high doses of antibiotics. But this is far from being true. Nowadays, fish farming is virtually free of antibiotics, while significant quantities of antibiotics are fed to cattle, pigs, dogs and cats in Norway”, says Oivind Bergh, leader of the Institute’s Fish Health and Disease research group.
“More antibiotics are used to treat mastitis in cattle - a very common disease in agriculture - than are fed to all Norwegian fish”, says Bergh.
According to the Norwegian Food Safety Authority, 5.75 tonnes of antibiotics were used in this country in 2000, 4.9 tonnes of which were administered to farm livestock and domestic pets. At the same time, the number of organisms in Norwegian aquaculture is much greater than the number of animals in agriculture. There are around 600 million farmed fish, as against somewhat fewer than 40 million chickens and a million each of sheep, pigs and cattle. Prescriptions of antibiotics for the medical treatment of 4.5 million Norwegians come to between eight and ten times as much as the total amount fed to animals.
All the same, Bergh does not attempt to hide the fact that the introduction of new farmed species creates new challenges.
“The scallop farming industry had problems for a long time, but in the course of the past few years, new methods of cultivation have completely eliminated the use of antibiotics in this species as well. However, a certain increase in the use of antibiotics in cod farming has been observed. If this is to become a major industry, new methods will have to be developed to put a stop to this trend”, says Bergh, who points out that disease-free farmed species have not emerged without cost, and that major resources still need to be put into implementing control measures for all species.
Environmental toxins in farmed fish?
This spring, an article in the journal Science about environmental toxins in farmed fish aroused great deal of international attention. The article claimed that farmed salmon contain such high levels of toxins that it was inadvisable to eat farmed salmon more than once a month.
“The authors based this conclusion on the controversial model that they used for their assessment of health risk”, says seafood researcher Marc Berntssen at Norway’s National Institute for Nutritional and Seafood Research (NIFES). According to internationally recognised risk models (WHO and the EU) it is quite safe to eat salmon several times a month.
“Farmed salmon contain important nutrients, and the problem is largely that we do not eat enough fatty fish. Like the food authorities in other countries, NIFES recommends eating at least two portions of fish a week, one of which can well be fatty fish such as salmon”, says Berntssen.
From Putting Paid to myths about farmed fish, Institute of Marine Research

Myths and Legends of Aquaculture exploded!
It is important that Irish consumers are told the truth about the food that they eat. All too often though, they are misled by glib phrases and sound bytes that make for exciting journalism but do not give the true facts.
Aquaculture products in general and farmed Atlantic salmon in particular have been the subject of more than their fair share of this sort of sensationalist treatment.

To set the record straight BIM have provided the follow articles as a service to Irish fish consumers. The articles tell the consumer what they need to know so that they can make healthy eating choices for themselves and their families. Further Articles will be added through out 2007.

Aquaculture Myth Busters
Myth one: “Farmed Salmon is full of dyes!”

Myth two: "Fish in salmon farms are kept in the equivalent of a bathtub full of water"
From Myths and Legends of Aquaculture

Fish Food, Books, Aquaculture and more!
Many myths and fallacies concerning nutrition and feeding of fish are often regurgitated over and over again until it "almost" becomes a fact.

Aquaculture Links
Challenging the myths and misinformation surrounding Aquaculture.

More Stories on Google

Largemouth Bass, Bluegill and Other Sunfishes

2007-01-28T14:28:00.000-08:00

Notes from Fundamentals of Aquaculture, James W. Avault, Jr., Ph.D., pgs. 84-85

Carnivorous largemouth bass is farmed commercially in Taiwan on a limited scale, this species is mainly sought for sport in areas it occurs naturally, or has been introduced. Largemouth bass has wide distribution range, from Southern Canada, the Great Lakes, south into Mexico, and on the Atlantic Coast from Virginia to Florida. The Florida strain is sought after because it grows faster and reaches a large size, making it a trophy fish. Because of its popularity, State and national hatcheries have propagated the largemouth bass for decades. Fingerlings have been stocked into public waters and distributed to citizens for private ponds.

The bluegill (Lepomis macrochirus) has been produced in state and national hatcheries in combination with largemouth bass. In new sportfishing ponds that are fertilized, bluegill fingerlings are stocked in the fall at 3707/hectare (1500/acre). The following spring, largemouth bass are stocked at rate of 247 fingerlings per hectare (100 acres).

With most species, when a culture species is grown for food it is not desirable to reproduce in grow-out ponds. But in largemouth bass-bluegill ponds, the pond may never be drained as long as the fishing remains productive. The pond owner would naturally want both species to spawn naturally. Bluegill are prolific and usually spawn the first summer after stocking, and may spawn up to three or four times, depending on water temperature (above 27 degreesºC (80ºF).

Bass spawn once annually, in the spring when water temperature reaches 21ºC or 70ºF. The largemouth bass depend on the bluegill for a source of food, to realize maximum growth potential. Thinned down, bluegill have ample food supply and also reach a desirable size for sportfishing. Both species expand, filling the pond to its maximum carrying capacity and fish population ultimately reaches a "balance".

This balance is determined by three causes
1. Both species must reproduce each year.
2. Good fishing must exist. Though it may vary, generally the pond should allow harvesting up to 56 kg/ha (50 lb/ac) of largemouth bass and 225 kg/ha (200 lb/ac) of bluegill.
3. The population of forage (F) species (bluegill) must be in a proper ratio by weight in contrast with the carnivore (C) (largemouth bass), determining that a pond ratio F/C ratio may range from 1.4 to 10.

A number of other sunfishes are popular for sportfishing. The red-ear (Lepomis microlophus) has been stocked into largemouth bass ponds, to add variety to fishing. It grows slightly larger than bluegills, but is not prolific enough to be stocked alone with largemouth bass. Both white crappie and black crappie (Pomoxis annularis and P. nigromaculatus) are both sport-fish that grow well in large reservoirs, more than 20 ha (50 acres), with largemouth bass, bluegill and red-ear. Crappie compete with these species for food and space, and all species may become stunted in smaller farm ponds.

Entrepreneurs who are considering propagating largemouth bass and sunfish for commercial purposes must take into account the existing competition with state and national hatcheries. Some states prohibit farming of sportfish for commercial food purposes. However, there are limited possibilities for private investors, probably the best being operations of fee-fishing managed lakes, which appeal to urban citizens. Fishing rights can be leased by the day or annually, or charging by weight of fish which are caught.

Largemouth Bass Culture

2007-01-27T21:25:00.000-08:00

Largemouth Bass, Micropterus salmoides

Largemouth bass are freshwater bass which belong to the family Centrarchidae.

Two subspecies:
1. Northern strain
2. Florida strain (Rook.org)

Scientists and anglers had already recognized by 1932 that largemouth bass in peninsular Florida grew to a larger size and had different coloration than their northern counterparts. These differences, as well as other physical characteristics, were used to classify Florida largemouth bass as a distinct subspecies in 1949. Although each is recognized as a unique biological unit, the two subspecies (Florida bass [Micropterus salmoides floridanus] and northern bass [Micropterus salmoides salmoides]) freely interbreed. Florida bass have been widely introduced throughout the nation because of their potential for producing trophy-size fish. However, native populations of this subspecies are unique only to the central and southern portions of the Florida peninsula. As a result, they represent a natural resource that is both biologically unique and economically valuable.(Black Bass Genetics in Florida)

Closely related species that are cultured:
1. Smallmouth bass (M. dolomieui)

2. Spotted bass (M. punctulatus)
(Texas State)

Largemouth bass live in warm, slow moving waters around rich vegetative soft bottoms. Smallmouth bass are a related game species found in faster, cooler water that may require less vegetative cover. Largemouth bass, Smallmouth bass and Spotted bass are known collectively as the Black bass.

Intensive Largemouth Bass Culture Commercial Production
North Carolina is one of the few states which permit commercial culture of bass. It is the only state on the East Coast that specifically permits licensed fish farmers to culture food-size Largemouth bass.

The Largemouth bass market is small. Currently live sales go to Asian-Americans in the northeastern US. Live haulers pick up live largemouth bass at the farm, and may pay up to $6 per lb, in cash. These fish must be at least 1.5 lbs, excellent physical condition and disease-free to bring this price. High price and ready market has resulted in recent interest in intensive commercial production of largemouth bass.

Dr. James Tidwell and others at Kentucky State University conducted research which demonstrate largemouth bass can be stocked at high rates, up to 5,000 per acre. Fed a high-protein pelleted feed, and grown to market size in a reasonable period of time (from 6” fingerlings to 1.5 lb fish in 12-18 months).
(Kentucky State University)

Problems with intensive production of Largemouth bass:
1. Cannibalism (well graded fish at stocking, additional grading may be required before fish are finished out).
2. Bird predation Compared with other species, birds are one of the greatest predators.
3. Unknown nutritional requirements.
4. No approved disease treatments.
5. Other problems yet to be determined (Very little intensive culture experience to go on at this point). (Purdue.edu)

Bass-Bream Culture in Farm Ponds
Farm ponds are most often hill ponds (also known as watershed ponds [Watershed or embankment ponds, are formed by constructing a dam to collect stream or surface runoff] NC State Fisheries). Excavated ponds are also sometimes constructed in low areas in the coastal plain for the same purpose.

Most farm ponds are located in the upper coastal plain and the piedmont in NC. They are used for many and varied purposes on farms throughout the U.S.A., including:
1. Irrigation
2. Livestock watering
3. Flood control
4. Erosion control

For reasons #3 and #4 above, many of these ponds have been constructed with large (up to 75% of cost) subsidies from the Soil Conservation Service since the 1930’s. More than 100,000 have been constructed in NC alone (NC has 60,000 farms, and most have at least 1 farm pond on the property).

Farm ponds once served another important function on farms in the Southeastern US: Production of fish as food for the farm family.

Homer Swingle (Auburn University, Alabama) conducted extensive research on the use of farm ponds as a source of high-quality fish protein for farmers in the South, beginning in the 1930’s. Swingle’s work laid the foundation for further research on farm-pond fish culture that continues to the present day.

Many states provide largemouth bass and bream fingerlings free of charge to farmers for farm-pond stocking. Many states, including North Carolina have discontinued this practice.

Largemouth bass and bream of various species are produced by private hatcheries for sale to individuals for private lake or ponds. It is a lucrative business, and there are several suppliers of Largemouth bass, bluegill, red-ear, hybrid bluegill, etc. in NC, including graduates of the BCC aquaculture program. (Southeast Pond Stocking of Pender County, specializes in largemouth bass, bluegill, shellcracker, channel catfish, grass carp, hybrid striped bass, koi, fathead minnows, hybrid bluegill, tilapia, black crappie, F1 hybrid largemouth bass) (NC State Agriculture) Currently only 3-4 active gamefish hatcheries exist in North Carolina and Southeast Pond Stocking, is run by BCC graduates Kevin Patterson and Rick Stuckman.

Most suppliers purchase fingerlings from private hatcheries and provide stocking services for private pond and lake owners. (A list of services, seponds.com)

Largemouth bass become carnivorous when they become adults, and having a preference for smaller fish, so ponds and lakes must be stocked with a suitable forage species to support Largemouth bass populations.

Debate continues over
1. Largemouth bass stocking rate.
2. Forage species stocking rate.
3. The best forage species to use.

Commercially, the most common forage species for Largemouth bass is the Bluegill (Lepomis macrochirus).
Bluegill image based on Michigan Science Art

Recommended stocking in North Carolina:

Unfertilized ponds:
a. 350/acre 1-2” bluegill stocked in Oct-Nov
b. 150/acre 1-2” red-ear sunfish stocked in Oct-Nov
c. (optional) 50/acre 2-4” channel catfish stocked in Oct-Nov
d. 50/acre 2-4” LMB stocked the following June

Fertilized (or fed) ponds:
a. 700/acre 1-2” bluegill stocked in Oct-Nov
b. 300/acre 1-2” red-ear sunfish stocked in Oct-Nov
c. (optional) 50/acre 2-4” channel catfish stocked in Oct-Nov
d. 100/acre 2-4” LMB stocked the following June

Many people avoid stocking catfish because catfish may upset the bass-bream “balance”. Some scientific evidence exists for this.

The preferred stocking strategy for ponds and small lakes (described above) in NC is because,

1. Bluegill and red-ear have traditionally shown to be an excellent forage species for bass.

2. Bluegill itself is an excellent foodfish for people. Some people prefer bluegill over bass.

3. Largemouth bass do a good job of keeping sunfish populations in check, preventing overpopulation and stunting.

The greatest problem in Largemouth bass/sunfish ponds is overfishing of bass, and/or underfishing sunfish, resulting in overpopulating the pond with sunfish. The sunfish then may become stunted, too small to be eaten by people, while bass population is reduced in number and larger, which are seldom caught by anglers.

To maintain the pond's “balance” a farm pond should be harvested on a regular schedule by angling :

Depending on productivity:

1. 10-40 lbs/acre of bass should be harvested each year.
2. 40-160 lbs/acre of sunfish should be harvested each year.

Use the lowest figures for unfertilized ponds constructed in soils of low fertility. Use the highest figures only for well-managed fertilized ponds built on highly productive agricultural land, or fed ponds. If a pond owner can’t eat 160 lbs of bream from his pond each year, give them away or bury them!

Stocking alternative forage species:

1. Red-ear sunfish (Lepomis microlophus) – has a lower reproductive rate than bluegill, so may be less likely to overpopulate or become “stunted”.

Red-ear sunfish (Lepomis microlophus), an alternative forage species for Largemouth bass.
Red-ear sunfish image based on Texas Parks and Wildlife
2. A 70:30 mix of bluegill and red-ear (as recommended by NC Cooperative Extension).

3. Hybrid bluegill – usually a cross between male bluegill and female green sunfish. Very popular with pond and lake owners, but not recommended, because:

a. Hybrids are 90% male, have a very low reproductive rate, and may not provide adequate forage for the bass.

b. The hybrids back-cross and revert back to a fish that most resembles green sunfish after 1-2 generations. Green sunfish rapidly overpopulate the pond and become stunted, useless as a foodfish for people.

Many other stocking and management strategies in other states and other regions of the US, depending on:

1. Climate
2. Soil fertility
3. Watershed chartacteristics
4. Other environmental factors.

Each state has developed its own recreational fishing pond management strategies and recommendations. Consult your local Cooperative Extension office for recommendations in your area.

References: Largemouth Bass, Texas State Parks and Wildlife

Notes from BCC with modifications and additions, January 28, 2006

Largemouth Bass, Micropterus salmoides

2007-01-27T18:33:00.000-08:00

Largemouth Bass, Micropterus salmoides

Image based on (Texas State Wildlife)

Physical Description and Taxonomy
Micropterus, from the Greek, "small fin" salmoides, from the Latin, salmo, "trout"; hence "trout-like" Common name from large mouth, the line of which extends back past the eye. Other common names include: Bigmouth Bass, Bigmouth Trout, Black Bass, Bucketmouth Bass, Green Bass, Green Trout, Hawg, Hog, Lineside, Lake Bass, Openmouth Bass, Oswego Bass, Slough Bass, Welshman

Taxonomy:
Kingdom Animalia
Phylum Chordata, animals with a spinal chord
Subphylum Vertebrata, animals with a backbone
Superclass Osteichthyes, bony fishes
Class Actinopterygii, ray-finned and spiny rayed fishes
Subclass Neopterygii
Infraclass Teleostei
Superorder Acanthopterygii,
Order Perciformes, perch-like fishes
Suborder Percoidei
Family Centrarchidae, sunfish
Genus Micropterus, black bass, largemouth bass (Rook.org)

Largemouth bass grow 4 to 6 inches (10 to 15 cm) during their first year, 8 to 12 inches (20 to 30 cm) in two years, 16 inches (40 cm) in three years. They are usually green with dark blotches that form a horizontal stripe along the middle of the fish on either side. The underside ranges in color from light green to almost white. They have a nearly divided dorsal fin with the anterior portion containing nine spines and the posterior portion containing 12 to 13 soft rays. Their upper jaw reaches far beyond the rear margin of the eye. (Texas State Parks and Wildlife)
Micropterus salmoides has a large mouth, a notch between the two dorsal fins, and a dark stripe along the side of the body (Bailey et al., 2004). This black band is seemingly made up of small oval shapes to a closer eye. Coloration is variable, but is usually a darkish green on the back and sides, fading to an off-white on the belly. The anterior dorsal fin has nine to eleven spines while the posterior dorsal fin has twelve to fourteen rays (Boschung et al., 2004). The average weight of M. salmoides is one kilogram; however, certain individuals have reached weights of over ten kilograms. Males usually do not surpass 40 cm, while females can reach up to 56 cm in length. (Bailey, Latta, and Smith, 2004; Boschung, Mayden, and Tomelleri, 2004) (University of Michigan)

Range/Habitat
Largemouth bass were originally distributed throughout most of what is now the United States east of the Rockies, including many rivers and lakes in Texas, with limited populations in southeastern Canada and northeastern Mexico. Because of its importance as a game fish, the species has been introduced into many other areas worldwide, including nearly all of Mexico and south into Central and South America. Largemouth bass seek protective cover such as logs, rock ledges, vegetation, and man-made structures. They prefer clear quiet water, but will survive quite well in a variety of habitats. (Texas State Parks and Wildlife)
Micropterus salmoides is native to eastern North America and historically ranged from southern Canada to northern Mexico, and from the Atlantic coast to the central region of the United States. Since the beginning of the twentieth century largemouth bass have been introduced successfully all over the world. (Carlander, 1977; Hubbs, 1964; Page and Burr, 1991) Largemouth bass prefer quiet, clear waters with abundant vegetation (Iguchi and Matsuura, 2004). More specifically, they prefer shallow water that is usually no deeper than 2.5 meters, but they sometimes occupy deeper regions. Abundant vegetation is important because it allows bass to hide from their prey and provides protection against predators.
Several countries report adverse ecological impact after introduction.(University of Michigan and fishbase.org)

Temperature Requirements
Growing: 55-80 F / 10 – 32°C; 47°N - 26°N (fishbase.org)
Spawning: 60-65 F (Purdue.edu

Feed/Diet
Fry feed primarily on zooplankton, aquatic insects and insect larvae. At about two inches in length they become active predators. Adults feed almost exclusively on other fish and large invertebrates such as crayfish and frogs. Larger fish prey upon smaller bass. Sunfish are the food of choice for most adult largemouth bass. Sometimes cannibalistic. (Olsen and Young, 2003, Texas State Parks and Wildlife, University of Michigan, fishbase.org)

Commercial Production
The production, rearing and stocking of largemouth bass (Micropterus salmoides) represents a large economic asset in the aquaculture industry of the midwestern U.S., requiring extensive information on the biology of this species.
(Calstate.edu Comparison of Experimental Growth Rates of Pond-Raised Largemouth Bass, Micropterus salmoides, Fed Natural and Artificial Foods)
Size: 1.0 - 2.5 lbs for food and 4-8 inches for fingerlings
Feed requirements: Protein: 40% diets are normally fed from fingerlings to adults after fingerlings have been trained to accept commercial diets.
Fat: 8-10%. Ponds for spawning and grow-out to food fish size. Small fingerlings are normally removed from ponds and trained to accept commercial diets using flow through systems. (Purdue.edu)

Spawning Requirements
In Texas spawning begins in the spring when water temperatures reach about 60°F. This could occur as early as February or as late as May, depending one where one is in the state. Males build the nests in two to eight feet of water. Largemouth bass prefer to nest in quieter, more vegetated water than other black bass, but will use any substrate besides soft mud, including submerged logs. As in Guadalupe bass, once the female has laid eggs in the nest (2,000 to 43,000) she is chased away by the male who then guards the precious eggs. The young, called fry, hatch in five to ten days. Fry remain in a group or "school" near the nest and under the male's watch for several days after hatching. Their lifespan is on average 16 years. (Texas State Parks and Wildlife)

Natural Enemies
Larval and juvenile largemouth bass are prey species of yellow perch, walleye, northern pike, and muskellunge. As adults, largemouth bass can usually escape most predators. The primary predators on adult largemouth bass are humans. (Paulson and Hatch, 2002) Preyed upon by herons, bitterns, and kingfishers (Ref. 1998). Excellent food fish (Ref. 1998). (University of Michigan and fishbase.org)

References: Largemouth Bass

Which Fish Do Fast Food Restaurants Use?

2007-01-27T13:46:00.000-08:00

McDonalds' Fish Filet Sandwich
The Filet-O-Fish is a fish sandwich sold by McDonald's since 1963. It contains a breaded fish patty made from Pollock or Hoki.
Source, 1 and 2

Alaska pollock is commonly used in the fast food industry, for example the fish filet at both McDonald's and Burger King are also made from Alaska pollock.
The Alaskan pollock is said to be "the largest remaining source of palatable fish in the world." Atlantic pollock is largely considered to be a white fish, although it is a fairly strongly flavored one. Alaska pollock has a much milder taste, whiter color and lower oil content. (Pollock, Wikipedia)

Rainbow Trout, Salmo gairdneri

2007-01-27T10:47:00.000-08:00

Rainbow Trout, Salmo gairdneri (=Oncorhynchus mykiss)
(Salmon Trout, Steelhead Trout, or Coastal Rainbow Trout)

Physical Description and Taxonomy
Class: Osteichthyes
Order: Salmoniformes
Family: Salmonidae
Genus: Oncorhynchus
Species: mykiss
In 1992 the steelhead trout, Salmo gairdneri (the species named in memory of Meredith Gairdner, a 19th-century naturalist) was reclassified in the genus Oncorhynchus ("hooked nose"), and mykiss (a Siberian word for the species). There are two races, both native to Western North America. The common name of the freshwater O.m. is rainbow trout, a colorful game fish that has been transplanted worldwide. The sea-run, or anadromous rainbow trout is called steelhead, a word that entered the common nomenclature in the early 1880s.
Unlike salmon, steelhead can spawn several times, although the hydropower dams on the Columbia River system have interfered with that pattern, and the species has been classed as threatened under the Endangered Species Act. On December 12, 2000, biologists for the Yakama Indian Nation released the first of 110 revived and rehabilitated kelts—as between-spawning steelhead are called—into the Yakama and Columbia Rivers. All were wearing identification tags, clipped fins, and inch-long cylindrical radio transmitters in their throats, for tracking, DNA testing, and genetic research. Record-class steelhead can attain a length of up to 45 inches, and a weight of more than 40 pounds. (Lewis-Clark.org)
In 1989 both the genus name and specific name of the rainbow trout were changed (see Smith and Stearley 1989). Thousands of publications cite Salmo gairdneri as the name of the rainbow trout; now we call it Oncorhynchus mykiss. The genus name was changed from Salmo to Oncorhynchus partly based on fossil evidence because the Pacific trouts were thought to be more closely related to the Pacific salmon than to the Atlantic salmon [the name carrier or type of Salmo]. Pacific trout and salmon are now classified as Oncorhynchus. The species name gairdneri was changed to mykiss when it was thought that mykiss from Kamchatka, Russia, was the same as gairdneri; since mykiss was described first, that name had priority for use over gairdneri. (Fishbase.org)

Native Range/Habitat
Steelhead is a name given to rainbow trout which live in the Great lakes. Rainbow trout are native to the Pacific Ocean along North America and to rivers and other fresh waters of North America west of the Rocky Mountains. They are a popular game fish, and for this reason have been introduced all over the United States.

Temperature Requirements
Great lakes steelhead are usually found in waters less than 35 feet deep at temperatures of 58-62 degrees F. They are often found near stream outlets, especially in spring and early summer.

Feed/Diet
In the lake-dwelling part of their life cycle, they wander along the shoals eating plankton, minnows, surface and bottom insects and other aquatic life. Although they feed primarily in mid-depths, they do take surface insects, including fly fishermen's flies. Larger rainbows will eat other small fish if available.

Commercial Production
Steelhead are valiant fighters and their flesh is outstanding no matter how it is cooked. An unbeatable combination that makes them one of the most popular North American sport fish. (Michigan.gov)
The production of rainbow trout has grown exponentially since the 1950s, especially in Europe and more recently in Chile. This is primarily due to increased inland production in countries such as France, Italy, Denmark, Germany and Spain to supply the domestic markets, and mariculture in cages in Norway and Chile for the export market. Chile is currently the largest producer. Other major producing countries include Norway, France, Italy, Spain, Denmark, USA, Germany, Iran and the UK.
There are many outputs from rainbow trout culture, which include food products sold in supermarkets and other retail outlets, live fish for the restocking of rivers and lakes for recreational put-and-take game fisheries (especially in the USA, Europe and Japan), and products from hatcheries whose eggs and juveniles are sold to other farms.
Products for human consumption come as fresh, smoked, whole, filleted, canned, and frozen trout that are eaten steamed, fried, broiled, boiled, or micro-waved and baked. Trout processing wastes can be used for fish meal production or as fertiliser. The fresh fish market is large because the flesh is soft and delicate, white to pink in colour with a mild flavour. Food market fish size can be reached in 9 months but 'pan-sized' fish, generally 280-400 g, are harvested after 12-18 months. However, optimal harvest size varies globally: in the USA trout are harvested at 450-600 g; in Europe at 1-2 kg; in Canada, Chile, Norway, Sweden and Finland at 3-5 kg (from marine cages). Preferences in meat colour also vary globally with USA preferring white meat, but Europe and other parts of the world preferring pink meat generated from pigment supplements in aquafeed.
Strict guidelines are in place for the regulation of rainbow trout for consumption with respect to food safety. Hygiene and safe transportation of fresh fish are of paramount importance, to ensure that fish are uncontaminated by bacteria, in accordance with food agency directives.
Status and trends
The rainbow trout farming industry has been developing for several hundred years, and many aspects are highly efficient, using well-established systems. However, current research and development is continually attempting to increase production efficiency and sales by increasing rearing densities, improving recirculation technology, developing genetically superior strains of fish for improved growth, controlling maturation and gender, improving diets, reducing phosphorous concentrations of effluents, and developing better marketing. One method that has been developed is a genetically modified hormone that is effective in reducing production costs. However, problems may lie ahead as public opinion towards genetically-modified products continues to be negative. As production continues to rise research is needed to keep costs to a minimum so the industry can move forward. (FAO.ORG)

Spawning Requirements
Great Lakes steelhead enter their spawning streams from late October to early May. At the present most spawning occurs in the spring, although more steelhead are beginning to spawn in fall. Spawning takes place in a bed of fine gravel, usually in a riffle above a pool. Steelhead don't necessarily die after this; they may live to reproduce for as many as five successive years. Most rainbow trout return home to spawn in the stream in which they were born or planted.
Trout eggs hatch in four to seven weeks, depending on water temperature. Young trout may travel downstream to the lake in their first summer, or they may remain from one to three years in their home stream before migrating lakeward.
Individual growth varies greatly even within the same population. Most Great lakes steelhead reach sexual maturity at age three to five years, ahead of females. A mature 16-inch fish living in the Great lakes may continue to grow throughout its life and could reach 36 inches in length and up to 20 pounds in weight. However, average adult size for steelhead in 9 to 10 pounds while life expectancy in the Great Lakes is six to eight years.

Natural Enemies
Larger fish, fish-eating birds and mammals and sea lamprey are the steelhead's natural enemies. In turn, the steelhead finds itself competing with other salmon and trout, other predatory fishes and a variety of bottom feeders, for its food. It also competes with salmon and trout for spawning grounds. (Mich.gov)
There are a variety of diseases and parasites that can affect rainbow trout in aquaculture, which are summarised here. Prevention is the most important measure; good hatchery sanitation by restricting access, installing disinfectant footbaths and disinfecting equipment reduces the exposure of vulnerable fish to disease-causing agents.
In some cases antibiotics and other pharmaceuticals have been used in treatment but their inclusion in this table does not imply an FAO recommendation. (Cultured Aquatic Species Information Programme, Oncorhynchus mykiss)

References
Steelhead, Oncorhynchus mykiss, Michigan.gov

Brook Trout, Salvelinus fontinalis

2007-01-26T22:52:00.000-08:00

Brook Trout Salvelinus fontinalis
(Speckled trout)

Salvelinus fontinalis (Mitchill, 1814)
Taxonomy and Nomenclature
Taxonomic Hierarchy
Kingdom Animalia -- Animal, animals, animaux
Phylum Chordata -- chordates, cordado, cordés
Subphylum Vertebrata -- vertebrado, vertebrates, vertébrés
Superclass Osteichthyes -- bony fishes, osteíceto, peixe ósseo, poissons osseux
Class Actinopterygii -- poisson épineux, poissons à nageoires rayonnées, ray-finned fishes, spiny rayed fishes
Subclass Neopterygii -- neopterygians
Infraclass Teleostei
Superorder Protacanthopterygii
Order Salmoniformes -- salmons, saumons
Family Salmonidae -- salmonids, salmons, trouts, trouts and salmons, truchas y salmones, truites et saumons
Subfamily Salmoninae
Genus Salvelinus Richardson, 1836 -- chars
Species Salvelinus fontinalis (Mitchill, 1814) -- brook trout, charr, omble de fontaine, salter, sea trout, trucha de arroyo

Taxonomic Rank: Species
Synonym(s): Common Name(s): brook trout [English]
charr [English]
omble de fontaine [French]
salter [English]
sea trout [English]
trucha de arroyo [Spanish] (itis.gov)

Physical Description
The brook trout's body is elongate with an average length of 38.1-50.8 cm, is only slightly laterally compressed; the body has its greatest depth at or in front of the origin of the dorsal fin (Scott and Crossman, 1985). Another physical characteristic of the brook trout is an adipose fin and a caudal fin that is slightly forked (Hubbs and Lagler, 1949). Brook trout have 10-14 principle dorsal rays, 9-13 principle anal rays, 8-10 pelvic rays, and 11-14 pectoral rays (Scott and Crossman, 1985). The brook trout also has a large terminal mouth with breeding males developing a hook or kype on the front of the lower jaw (Scott and Crossman, 1985).
The coloration of the brook trout is very distinct and can be spectacular. The back of the brook trout is dark olive-green to dark brown, sometimes almost black, the sides are lighter and become silvery white ventrally (Scott and Crossman, 1985). On the back and top of the head there are wormy cream colored wavy lines known as vermiculations which break up into spots on the side (Scott and Crossman, 1985). In addition to the pale spots on the side there are smaller more discrete red spots with bluish halos (Scott and Crossman 1985). The fins of the brook trout are also distinct; the dorsal fin has heavy black wavy lines, the caudal fin has black lines, the anal, pelvic and pectoral fins have white edges followed by black and then reddish coloration (Scott and Crossman, 1985). (Hubbs and Lagler, 1949; Scott and Crossman, 1985)Some key physical features: ectothermic ; heterothermic ; bilateral symmetry. (umich.edu)

Native Range and Habitat
Brook trout are found as far south as Georgia in the Appalachian mountain range and extend north all the way to Hudson Bay. From the east coast their native range extends westward to eastern Manitoba and the Great Lakes (Willers, 1991). The fish has been introduced, very successfully in some areas, into many parts of the world including western North America, South America, New Zealand, Asia, and many parts of Europe (umich.edu)
The brook trout is native to small streams, creeks, lakes, and spring ponds. Some brook trout are anadromous. Though commonly considered a trout, the brook trout is actually a char, along with lake trout, bull trout, Dolly Varden and the Arctic char. It is native to a wide area of eastern North America, including most of Canada from the Hudson Bay basin east, the Great Lakes–Saint Lawrence system, and the Mississippi River drainage in the United States as far south as northern Georgia. (Wikipedia)

Temperature Requirement
Brook trout require cool, clear, spring-fed streams and pools. They can be found under cover of rocks, logs, and undercut banks and have been described as stationary. Larger brook trout often inhabit deep pools moving to shallow water only to feed. They prefer temperatures from 57–60 degrees F. (Michigan.gov)

Feed/Diet
Brook trout have been described as voracious feeders with the potential to consume large numbers of zooplankton, crustaceans, worms, fish, terrestrial insects, and aquatic insects. Ephemeroptera, Trichoptera, and Diptera often make up a large component of their diet. However, they will often feed on whatever is most readily available.
Brook trout are avidly sought after by sport anglers, for food as well as for the sport. They can be caught by using various bait and lures including worms, crickets, grasshoppers, wet and dry flies, spoons, and spinners. (Michigan.gov)

Commercial Production
The potential for commercial production of brook trout Salvelinus fontinalis, however, is constrained by the lack of published protocols for producing the sex-reversed males required to create monosex female stocks. Immersion and immersion plus feeding treatments with 17α-methyltestosterone (MT) and 17α-methyldihydrotestosterone (MDHT) were applied to genotypically female gynogenetic brook trout to induce phenotypic sex reversal. The fry were exposed to a 6-h immersion in a solution of MT or MDHT on day 10 following completion of hatch and/or to a steroid-treated diet for 60 d beginning at first feeding. Immersion dosages were 0.5 or 1.0 mg/L, and feeding dosages were 1.0 or 2.0 mg/kg of feed for MT and 0.5 or 1.0 mg/kg for MDHT. Phenotypic sex of the fish was determined 19 or 22 months after first feeding. Control gynogenetic fish were 100% phenotypic females. Treatments with MT had minimal effect: most fish remained female, with only a low incidence of phenotypic males (1-3% in four of the treatments), intersex fish, or sterile fish. In contrast. a substantial number of phenotypic males were observed in several of the MDHT treatments, with the highest proportion (45%) occurring in the 0.5 mg/L immersion plus 0.5 mg/kg feeding treatment. Sperm was obtained from 29 males from five MDHT treatment groups and one MT treatment group examined at maturity (22 months) and was used in progeny tests of these males. The progeny were 100% female, confirming the male parents to be genotypically female. These protocols may be used to create sex-reversed brook trout males for the production of monosex female progeny, although additional trials are ongoing to test similar MDHT immersion dosages applied once or multiple times, with or without feeding treatments, to identify protocols with increased efficacy. (cat.inist.fr)
The brook trout is very popular with anglers, particularly fly fishermen. Today, many anglers practice catch-and-release tactics to preserve remaining brook trout populations, and organizations such as Trout Unlimited have been in the forefront of efforts to institute air and water quality standards sufficient to protect the brook trout. Revenues derived from the sale of fishing licenses have been used to restore many sections of creeks and streams to brook trout habitat. Brook trout are also commercially raised in large numbers for food production, being sold for human consumption in both fresh and smoked forms. Because of its dependence on pure water and a variety of aquatic and insect life forms, the brook trout is also used for scientific experimentation in assessing the effects of pollution. (Wikipedia)

Spawning Requirements
Brook trout spawn in the fall within sand and gravel areas where upwelling groundwater occurs. Lake-dwelling fish spawn in tributary streams or along the shoreline. Spawning takes place from late September to November during daytime, by contrast with night-time spawning lake trout. As spawning season approaches the colors of brook trout are greatly intensified, especially in males whose flanks and belly become orange-red with a black stripe along each side. Aggregations of spawning brook trout can often be observed in small tributaries and along lake shorelines, with solitary females seen digging and remaining within the perimeter of shallow nests, and numerous males looking for an opportunity to dart into these nests to fertilize eggs deposited by the resident female. Brook trout "redds" or nests are often found in large aggregations.
Surviving brook trout eggs hatch from February to April, still buried within their gravel spawning beds. Young brook trout grow faster than lake trout because small brook trout are able to live in warmer nearshore and tributary areas that produce abundant insect larvae and other small crustaceans. Larger brook trout are able to feed upon small fish and crayfish, though these fish are also restricted to cold, deepwater habitats during warm mid-summer conditions. Although brook trout are relatively acid-tolerant and can withstand pH conditions as low as 5.0, many brook trout populations in the southwestern Adirondacks and Catskills have been eliminated or greatly reduced due to decades of acid rain deposition. Brook trout have also been eliminated from suitable coldwater habitats within lakes and streams due to predation and competition with non-native smallmouth bass and brown trout. (Cornell.edu)
Brook trout spawn in late summer or autumn depending on the latitude and temperature (Scott and Crossman, 1985). The type of area required for brook trout spawning is one that offers loose, clean gravel in shallow riffles or shoreline area with an excellent supply of upwelling, oxygen-rich water (LaConte, 1997). Mature fish have been known to travel many miles upstream to reach adequate spawning grounds (Scott and Crossman, 1985). Females are able to detect upwelling springs or other areas of ground-water flow, which make for excellent spawning grounds. Brook trout reach maturity on an average at the age of two and spawn every year, although their size at first maturity depends on growth rate and the productivity of thier habitat (Everhart, 1961). Males often outnumber females at the spawning site, but only rarely is more than one male able to fertilize the eggs in a particular redd (Scott and Crossman, 1985; Blanchfield et al., 2003). The females clear away debris and silt with rapid fanning of her caudal fin while on her side, creating a redd (Scott and Crossman, 1985). The redd is where the eggs will be deposited and fertilized after the males compete for spawning right to the female (Scott and Crossman, 1985). The redd actually resembles a pit that is 4-12 inches in depth (Everhart, 1961). To gain the spawning right of the female the males compete for position by nipping and displaying themselves to the competitor males (Mills, 1971). When spawning is actually taking place the male takes a position to hold the female against the bottom of the redd and both of the fish vibrate intensely while eggs and milt are simultaneously discharged (Scott and Crossman, 1985). Very shortly after this exchange takes place the female works to cover the fertilized eggs with gravel by digging slightly upstream and letting the current carry the gravel down to fill the redd (Everhart, 1961). The eggs are initially adhesive to prevent them from washing away so they are able to incubate within the gravel (Scott and Crossman, 1985). The total time of incubation depends on factors such as temperature and oxygen (Scott and Crossman, 1985). After hatch the fry remain in the gravel until the yolk sac is absorbed then the fry swim up out of the gravel to begin the next stage of their life (Scott and Crossman, 1985). (Blanchfield, Ridgway, and Wilson, 2003; Everhart, 1961; LaConte, 1997; Mills, 1971; Scott and Crossman, 1985 (umich.edu)