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Ictalurus punctatus
Cassidy Brittain, Ryan Muskal & Sam Mendicino
Cassidy Brittain, Ryan Muskal & Sam Mendicino
Introduction
Introduction
In the early 1900s, a band of brave scientists dared to experiment with the natural order. These men and women refused to conform to society, and conducted experiments that most of us would see as unethical. In 1906, this brave conglomerate plotted to combine two of the most common organisms in human life: the cat and the fish. The resulting animal was aptly named the catfish.
No, none of that is true, but hopefully we have your attention now! While the catfish is not an amalgamation of different species, it is still an incredible specimen. Catfish comprise 12% of teleosts (a major subdivision of ray-finned fishes) and 6.3% of all vertebrate species (Liu, 2016). The best of all catfish species (not yet experimentally proven) is the channel catfish, a native to the Mississippi Basin. Channel catfish are considered excellent tableware, and are often kept in hatcheries and released in local ponds for recreational fishers. Catfish has now become so prominent in the Cape Fear River that a 2014 study found catfish to comprise 17% of overall catch.
Channel catfish taken by Sam Mendicino at Carolina Beach State Park
Fun fact: Catfish never stop growing, the larger ones tend to be the older ones. Channel catfish are about 12-24 inches long weighing about 2-7 pounds, on average. Many of them can grow larger than this with the record set at 52 inches long weighing 58 pounds. Generally, catfish can be distinguished from other fish by their scaleless, smooth bodies. Channel catfish color can range from an olive color to light blue with black freckles on the side. Their tail is forked, their body slender, their head broad and flat, and they have whisker around their mouth known as barbels. These barbels are used to help catfish locate food in dark or murky waters.
Taxonomy
Taxonomy
Kingdom: Animalia
Phylum: Chordata
Class: Teleostei
Order: Siluriformes
Family: Ictaluridae
Genus: Ictalurus
Species: Ictalurus punctatus
Common name: channel catfish, channel cat, fiddler, blue cat, lake catfish, willow catfish, spotted cat, Great Lakes catfish, lady cat
The idea that catfish sting is a common myth about its species. Instead they have whisker-like organs around their mouth called barbels (circled on image). These are loaded with taste buds and olfactory sensors assist in locating food especially in darker waters. They are also scaleless and have taste buds all over their body! Since they have poor vision the enhancement of other senses is crucial.
Communication to predators is also common with catfish. The channel catfish produces sound through the use of stridulation with their bony parts of their pectoral fin and girdle. The sudden loud noise is used as an avoidance tactic as well as alerting other catfish that a predator is in the area.
Circled: barbels on a catfish
Niche and Habitat
Niche and Habitat
The channel catfish is considered to be an omnivore that feeds both on living and dead matter. Smaller catfish tend to stick to aquatic insects as their meal while larger ones will also eat terrestrial insects, small crustaceans, seeds, birds, spiders, crayfish, spiders and plant matter such as wild fruits, weed seeds and anything that falls into the streams and rivers from hanging branches. In addition to all these, channel catfish are known to eat crappies, bluegills, minnows, shad, eels and sunfish depending on their availability.
Channel catfish typically live in moderate flowing streams but are also the most abundant in large lakes, ponds, reservoirs and some muddy waters. They prefer waters with sand, gravel, or rubble at the bottom. These catfish are considered freshwater fish but they can also thrive in brackish waters. Channel catfish tend to favor clear water streams but are known to do well in muddy waters too. During the daytime they can be found in deep holes where there is protection of rocks and logs. The young channel catfish will typically feed in shallow riffle areas and the older ones will feed deeper into the water directly downstream from the sandbars. The adult catfish tend to remain sedentary almost never moving from one area to another while the younger ones move about much more, especially when feeding
Shaded orange areas: native range of channel catfish in the United states
Diamonds: individual specimens that were introduced
Channel catfish are native in the southern Canadian Prairie Provinces to the Gulf States, east to the Appalachian Mountains and west of the Rocky Mountains. However, these catfish have been introduced to other parts of the United States outside its' native range for sport fishing. Due to its tolerance to extreme environmental conditions, high fecundity and resistance to disease, the channel catfish has been very successful in establishing itself in the areas it has been introduced. The channel catfish has been introduced to more than 32 countries around the world including, China, Russia, Japan, Italy and Brazil for recreational fisheries and aquaculture. Since its' introductions to areas outside its' native range, channel catfish can be found almost everywhere in the United States
A terrified graduate student about to dissect a channel catfish, photo taken by Dr. Amy Taylor
Evolutionary History
Evolutionary History
Catfish have grown to utilize the extremely productive benthic zones of the lakes and rivers that they inhabit. Channel catfish are also known to venture into brackish waters, although they tend to thrive mainly in freshwater. The channel catfish has an especially keen sense of olfaction, with olfactory receptors found all over the body and the barbs. The barbs are the string like features that give the catfish the classic "mustache" look. In fact, channel catfish have such an acute sense of olfaction -or smell- that they are sensitive to chemical cues as small as amino acids at a concentration of one part per million in the water they live in (eol). Another pronounced evolutionary adaptation that makes the channel catfish unique and successful in its environment is a derived sense of hearing. Catfish are noted to have a "Weberian apparatus," a specialized morphological feature connecting the swim bladder to the ear (Lechner, 2011). This apparatus allows the catfish to amplify vibrations that the swim bladder picks up.
Both of these adaptations aid in channel catfish communication and food recognition. The abundance of olfactory receptors may aid catfish in a low light environment to sense chemical cues within their environment, and even to recognize pheromones from other channel catfish in the surrounding area (Jamzadeh, 1992). Their sense of hearing also plays a role in courtship (Copeia, 1997), and catfish are also known to create loud and sudden sounds in an attempt to intimidate and discourage pray (eol).
Conservation
Conservation
The channel catfish is neither endangered or federally listed. Currently, Ictalurus punctatus, is of least concern and low conservation status which does not require any additional management, protection, research action or monitoring. This species of catfish is popular for their recreational fishing and are managed by state recreational fishing regulations though size limits and creel limits. There are many channel catfish farms that exist in the United States that are used to introduce these fish into areas for recreational fishing.
In some areas where it has be introduced, the channel catfish is a threat to the native species that live there. Since catfish are opportunistic feeders they can negatively impact indigenous species. Soon they may outcompete other fish for habitat and food.
razorback sucker (Xyrauchen texanus): critically endangered
Humpback chub (Gila cypha): endangered
Yaqui catfish (Ictalurus pricei) : endangered
Environmental Impacts
Environmental Impacts
In some areas the channel catfish is an invasive species. They are thought to have negative impacts on biodiversity in areas where it has been introduced, threatening many small and large endangered species of fish due to their predation on juveniles and resource overlap between adults and subadults. Channel catfish are a prolific predator all around the upper basin of the Colorado River. In the Gila River, along the Colorado River in California, the channel catfish is a major predator of the razorback sucker (Xyrauchen texanus) which is critically endangered. Due to the presence of channel catfish in the Gila River efforts to re-establish the razorback sucker have failed. In addition to threatening the populations of razorback suckers, the channel catfish feeds on the spawn of M. americana, Alosa sapidissima (Atlantic shad), A. aestivalis(blueback herring) and A. pseudoharengus (alewife) and preys on Callinectes sapidus (blue crab) and Morone americana (white perch) in the James River threatening their populations as well. Channel catfish are also known to hybridize with the Yaqui catfish (Ictalurus pricei) in Mexico, which is threatened, and the native headwater cat (I. lupus) in New Mexico. This is just a very short list of the possible organisms that invasive channel catfish affect.
The channel catfish is built to be an invasive species. They already have a very broad range in which they are abundant and sometimes invasive in. Channel catfish have not only shown to be invasive in their native range but also well beyond it. Being highly adaptable to different environments and tolerating, even benefiting from, mutilation, cultivation, fire and browsing pressure allows this fish to be as successful as we've seen. In addition, this species of catfish tend to live long, grow fast, have high genetic variability and have a high reproductive potential which from an evolutionary standpoint allows them to also be so abundant in areas. This invasiveness can result in many adverse affects not only on individual species but the ecosystem as well. Invasive channel catfish may alter trophic levels, change/alter habitat, increase vulnerability to invasions, damage ecosystem service, change the gene pool, modify natural benthic communities and much more. One of the biggest concerns, as mentioned in the paragraph above, is threat or loss of endangered and/or native species. Not only are we at risk of losing species that are threatened and endangered but we are also at risk of reducing biodiversity in areas where invasive channel catfish are taking over. Although the channel catfish is a popular sport fish and regulated in 31 states in the United States, we need to consider the long term, negative effects of having them everywhere in our waters.
Friends or Foes?
Friends or Foes?
Catfish have a primarily predator or prey relationship in the ecosystem. They are either feeding on species like aquatic larvae, insects, crayfish, and snakes or avoiding predation from larger fish such as flathead catfish. However, these intimidating species can coexist with others! Some mussel species use the catfish as a host for their larvae. These larvae are stored in their gills where they then fall to the bottom of the water to grow. Channel catfish and humans have a close and relatively mutualistic relationship with one another. The large catfish population provides humans with recreational and commercial fishing. It serves as a fresh catch food source for restaurants in many areas. This allows humans to keep the catfish population in balance as well as introduce them in new areas as needed.
When juvenile, channel catfish are more susceptible to predators such as yellow perch, pelicans, and herons. Depending upon the body of water that the channel fish are introduced will affect what types of predators they encounter. Aquatic and terrestrial species hunt catfish. In shallow waters animals such as alligators, raccoons, snakes, otters, and others will try to catch a catfish for dinner. The adult catfish's large size as well as their presence of spines reduces predation. As channel catfish mature their diets evolve becoming increasingly piscivorious. They compete with bluegill and large mouth bass when food sources have dwindled. However, can coexist if resources are plentiful. When introduced in non-native areas they will then compete with that body of waters top predators for resources possibly altering direct and indirect relationships present. It is possible in some areas for catfish to outgrow all of their predators except for humans!
Channel Catfish in the Tar River Fishing North Carolina Monster Fish Challenge
How to identify different species of catfish
Albino Channel catfish
Web Resources for Audience to Explore
Web Resources for Audience to Explore
- https://www.ncwildlife.org/Learning/Species/Fish/Channel-Catfish#5215593-overview : info about channel catfish fishery
- https://www.catfishedge.com/channel-catfish-tips/ : tips for fishing catfish!
- https://fishchoice.com/buying-guide/channel-catfish : seafood profile, biology & habitat, science & management, conservation, sustainability and suppliers
- https://www.nature.com/articles/ncomms11757 : article The channel catfish genome sequence provides insights into the evolution of scale formation in teleosts
- https://thefishsite.com/articles/cultured-aquatic-species-channel-catfish : how to farm a channel catfish
- https://www.cabi.org/isc/datasheet/79127 : just a TON of info about channel catfish including a complete list of everywhere in the world they have been introduced and where they are invasive
Resources
Resources
- https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=163998#null
- https://www.cabi.org/isc/datasheet/79127
- https://thefishsite.com/articles/channel-catfish-life-history-and-biology
- https://www.fws.gov/fisheries/freshwater-fish-of-america/channel_catfish.html
- https://www.iucnredlist.org/species/202680/18236665
- https://www.catfishedge.com/catfish-species-basics/
- https://forum.americanexpedition.us/channel-catfish-facts-info-and-photos
- https://www.nature.com/articles/ncomms11757
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3075255/
- https://www.jstor.org/stable/1447295?seq=1#page_scan_tab_contents
- https://link.springer.com/chapter/10.1007/978-1-4757-9655-1_61
- https://eol.org/pages/204762/articles
- https://www.jstor.org/stable/4608557?seq=1#page_scan_tab_contents
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