How Fish Smell and Breathe

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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.
Sense of Smell
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Sense of Smell
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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.

Sense of Smell


Additional images of Koi Nares
Sense of Smell
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Labels on nares (nostrils) and barbel which are also involved with scent.

Sense of Smell
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Sense of Smell
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Sense of Smell
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Sense of Smell
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Sense of Smell
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Sense of Smell
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Sense of Smell
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This weekend I also worked on "How Fish Breathe," and doing an overview on the gills.
Sense of Smell
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Aquaculture - Koi Diet

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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.

Dehydrated Baby Shrimp for Koi

After reading, I visted Wal-Mart and purchased some floating pellets and dehydrated "Baby Shrimp" specially formulated for Koi and Goldfish.
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Southeastern Plankton Monitoring Network (SEPMN)

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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.
Phytoplankton

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:
Phytoplankton
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...
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Fish Brain

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

Fish Brain
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Fish Brain

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 and Gastropod Project
Mollusk / Gastropod Project at Brunswick Community College

Mollusk and Gastropod Project
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Mollusk / Gastropod Project


My fish aquarium
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.
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Nitzschia sp.

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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
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Hybrid Striped Bass - White Grub and Yellow Grub

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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.

Hybrid Striped Bass
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of snail eggs on driftwood

(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.
Hybrid Striped Bass
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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).
Hybrid Striped Bass
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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...

Snail
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Ceratium furca - Dinoflagellate

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Ceratium furca
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.
Fish Kill
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
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Koi - show fish

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Koi

Images enlarge to full resolution.
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.
Koi

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.
Koi

Koi

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

Koi

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.
Koi

Koi

Koi

Koi
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Diatoms in Atlantic Ocean

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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.
Plankton
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
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