Ictalurus punctatus

Ictalurus punctatus
(Channel catfish)

General Information
Identification
Habitat and Geography
Adaptation
Nutrition
History and Reproduction
Interaction With Others
Interesting Facts
Links and Bibliography
Author

General Information

The Ictalurus punctatus, or more commonly called the channel catfish, is a very unique and interesting species. Depending on where you are, some might call the Ictalurus punctatus by any of these names as well: channel catfish, spotted catfish, spotted cat, lake catfish, Great Lakes catfish, northern catfish or fiddler. Here is how the Ictalurus punctatus got its name.

Domain - Eukarya
The organism was placed into this Domain because it is a multi-cellular organism.

Kingdom - Animalia
The organism was placed into this Kingdom because it is responsive to the environment, typically consumes its food, develop fixed body parts and normally develop as an embryo.

Phylum - Chordata
The organism was placed into this Phylum because is a vertebrate and at some stage in its life has a notochord.

Class - Actinopterygii
The organism was placed into this Class because the organism has ray-fins, not the typical fleshy lobed fins.

Order - Siluriformes
The organism was placed into this Order because of the prominent barbels (whiskers) it has.

Family - Ictaluridae
The organism was place into this Family because it lives in North America.

Genus - Ictalurus
The organism was placed into this Genus because it has a forked-tail.

Species - Ictalurus punctatus
The organism was given this scientific name because it of the Genus it belongs to and punctatus means "spotted" in Latin. That s why this catfish is sometimes called the "spotted cat," but more commonly just called the channel catfish.

Identification

    There are many different species of fish that look similar to the Ictalurus punctatus, but here are a few ways to identify the species from other species. This is a reminder though that these ways might not always be correct and you should consult an expert for official clarification.
        1.) The Ictalurus punctatus does not have scales. It has a thick tough skin instead of scales.
        2.) Most are colored blue to olive green on their backs, whitish bellies and silvery sides.
        3.) Along with being those colors, it will have black dots, possibly different sizes. This is the only species in the family to have      these spots. The spots are located on the sides of the fish.
        4.) The caudal (tail) fin is deeply-forked.
These are just some of the ways to identify a channel catfish, below is an illustration of the forked-tail and black spots.

Habitat and Geography

As mentioned above, Ictalurus punctatus is a bottom dwelling organism. Channel catfish are mainly found in rivers, but are also in lakes and occasionally ponds. This species can be found throughout the contiguous United States and some parts of Canada.
That covers the where in general they live, but where do they specifically congregate? This is a very interesting question because they are bottom dwellers, but do not have a specific bottom needed to live on. Typically they stick with rocky or weedy bottoms, but can also be found on sand and muddy ones. They prefer clear slow-moving water, but can be found in almost any condition. Seeing as they have no specific living area they can be found throughout the water systems, the only thing they need is water deep enough to cover them and enough to allow them to move fully so they do not suffocate. Now to challenge what was just stated above, channel catfish are more likely to be found in certain areas as pointed out above, but it also depends on the time of day and the time of year as well. During the cold months, channel catfish are more likely to be found in the middle of the river or body of water they are dwelling in, but during the warm months they are likely to be found in the shallows during the night to feed, but deeper during the day to rest.
The image shows a channel catfish "resting" during the daytime hours.

Adaptation

The channel catfish is adapting to something new every day that it is alive. Whether it be the weather changing, the water being polluted or just the swimmer or boater, this fish must adapt all the time. With the swimmer and boater most of the time the channel catfish just needs to move to adapt to the new situation in its environment. Channel catfish are a very resistant fish, they can survive in waters that most fish would not be capable of surviving in. The channel catfish are still affected by the pollution, but it does not seem to as fatal to them as many other species of fish. Pollution could be typical pollutants or things such as pH change, oxygen level, nitrogen level, etc. One of the more astonishing adaptation that most freshwater fish go through is the change in water temperature. During winter it can get as cold as 32°F (or colder in some cases) or even as high as 75°F (or higher in some cases), which results in a temperature difference of around 45°F (more or less depending on temperatures). Even in the Great Lakes the channel catfish have adapted to eat a new organism that was not native to the area called the Zebra mussel (Dreissena polymorpha). The channel catfish is one of the first recorded native organisms that consumes the Zebra mussels in North America.

Nutrition

Channel catfish are known for eating anything and everything. They eat live prey or just scavenge around for whatever is available. They are technically omnivores, but more often then not they consume other living organisms. The typical food for channel catfish is Whitebass crayfish, mussels, clams, small fish, insects and wild vegetation. Channel catfish are what we Bluegill would call "garbage disposals" because they eat almost anything they come across. They have even been known to eat a bar soap when used as bait. This fish will eat anything, to both sides is a picture of a smaller fish that the channel catfish can consume. The sizes of the fish pictured are getting to be the maximum size an average size channel catfish would be able to eat seeing as they are only two to four pounds on average.

History and Reproduction

Channel catfish reproduce like most fish by the female laying her unfertilized eggs outside of her body into a nest and the male comes along and releases his milt (sperm) onto the eggs to fertilize them. The unusual aspect is that the male builds the nest and after the male is done mating, he chases the female away from the nest. The male then watches over the nest until the eggs hatch. Once the eggs hatch, the male continues to watch over them until they absorb their entire yolk-sac and leave th nest in a massive school or "black cloud." After leaving the nest with the school of catfish fry, the young catfish are on their own until they reach mature age, which for channel catfish is more by size rather then age, and that size is approximately 12 inches. Once they reach their maturity to start mating, they will mate for the rest of their lives. The mating takes place during the month of July typically when the water is the warmest and give the young the highest chance to survive. Females lay from 3,000 eggs up to 30,000 eggs each year. Most channel catfish in the north tend to live about 8 years and start reproducing at around age 3, so over the course of their lifetime they could have approximately 150,000 eggs spawned.

The channel catfish does not have a very deep history on it yet because documentation of it did not begin until approximately 200 years ago. To this date there is still much to learn about the fish and many more interesting facts to discover about everything this organism does. Below is a phylogenetic tree of the species starting with its Order. It shows the most closely related organisms. A full phylogenetic tree has not been completed to date, so a small "family tree" is being used. If you trace the species back it will show that ray-finned fish, such as the sting-ray, etc. are more closely related to this organism then a human is. When a full phylogenetic tree becomes available, it will be placed along with the one already shown. The species is still slightly unique so all the classifications for it have not been determined as of yet.

Interaction With Others

This organism is one of the "top dogs" in the freshwater system in North America. Once the channel catfish has matured, it has no known natural predators. While it is growing up though it can be eaten by anything larger then it, although if the barbs on its fin stab you, it might hurt a little; it has drawn blood from me before. This organism will eat almost any other organism it comes into contact with so it is a very predacious organism and most tend to shy away from interacting with it. Humans tend to deal with this organism frequently, most of the time as a sport fish. This fish is also commercially fished for because it is a very tasty fish.

Interesting Facts

    I will start this section off with an interesting story rather than a fact. My brothers and I love to fish and while fishing for channel catfish one night off the end of our dock on Lake Winneconne, my oldest brother cast out his line and let it sit on the bottom like we typically do. After taunting the line he set his pole into a cement block so the tip was up in the air. Then he sat down and we continued fishing for a while with no luck. After about 30 minutes or so all-of-a-sudden his pole jerked forward pulling the cement block and his pole into the water. My brother then lunged from his chair to try and grab the pole before it fell into the water, but unfortunately missed and he lost his new pole. He had a few choice words for that fish, which we are pretty positive it was a large channel catfish because of the way it hit the line and it was what we were fishing for. All-in-all it was hilarious watching my brother get beat by a big cat.
    There are many interesting facts about catfish in general as well, like how they got to be called catfish. Imagine that it is because they share characteristics that cats have. They are nocturnal hunters in general just like cats are and also have whiskers. The whiskers on cats are used for balance and other such sense; the whiskers on catfish are used for aiding in maneuvering through deep water that is not very visible.
    Something else that confuses people about channel catfish is that once they grow up, they begin to lose their spots that make them easily identifiable. In the north it does not really cause for much confusion because there are typically only channel and flathead catfish, but in the south were there are blue catfish, people will often mistake an older channel cat as a blue cat. This is still slightly difficult to do though because blue catfish have a bluish color to them and channel catfish are black or olive greenish.

Links and Bibliography

Listed below are a few links that you can find useful information on or people to contact to find out more specific information.

www.procats.com
dnr.wi.gov
Your local DNR would be able to help as well.

References:

Duval, Michael C. Early Life History Of Channel Catfish (Ictalurus punctatus) In Navigation Pool 7 Of The Upper Mississippi River. La Crosse, WI. 1986.

Holtan, Paul. “Catfish.” Wisconsin Department of Natural Resources Bureau of Fisheries Management. 1998.

Larson, Tim, Ranthum, Richard G. “Fish Management Report 99.” Madison. Wisconsin Department of Natural Resources, 1977.

Meyer, Fred P., Sneed, Kermit E., Eschmeyer, Paul T., eds. The Status of Warmwater Fish Farming and Progress in Fish Farming Research.

Washington D.C. Bureau of Sports Fisheries and Wildlife, 1973.

U.S. Department of the Interior. The Status of Warmwater Fish Farming and Progress in Fish Farming Research.

Washington D. C. Bureau of Sports Fisheries and Wildlife, 1970.

Author

Kirk Gallant
University of Wisconsin - La Crosse
Biology Department

If you have any questions, comments, suggestions or found any errors, please email me at:
gallant.kirk@students.uwlax.edu