Originally Posted by FishBrew
Catfish Names and Descriptions
In the world, there are over 2,200 species of catfish. The only continent they have not been found on is Antartica. This article will focus on the 5 most common caught in North America.
To be a "cat", it must have whiskers, technically called barbels. All North American catfish have 8 barbels around the mouth. No catfish has scales. Some species have overlapping plates, like protective shields, but no scales. One of the most common and easiest ways to identify catfish is counting the rays on its anal fin. The anal fin (not tail fin) is fairly long and located on the bottom of the fish between the belly and the tail. The environment a catfish is in can largely effect its color scheme. How darkly or lightly colored a catfish is can be affected by its age, the season, the spawn, the depth, and its diet.
Common "Cat" Names: blue, channel, humpback, fulton, silver, white, highfin, fork tail.
Blue catfish colors range from a slate-blue to dark gray along the back & sides with a pale white belly. The inexerienced angler can confuse the blue and channel cats. The blues anal fin has a straight outer edge with 30 or more rays.
Common "Cat" Names: blue, channel, fiddler, speckled, spotted, chucklehead, willow, fork tail. Some of these names are the result of channel cats being separated into different species until the 1940's.
Channel cats range from gray to silver to copper to brown with a white belly. The sides of the younger ones tend to be peppered with black spots. They have a deeply forked tail and the upper jaw extends well beyond the lower. The anal fin has a rounded outer edge and 24 to 29 rays.
Common "Cat" Names: yellow, shovelhead, mud, tabby, johnnie, Op, Opelousas, Mississippi, flatbelly.
Brute power and a noticeably wide, broad head are the trade marks of the flathead. Back and sides tend to be yellow-brown with some mottling. The belly can range from yellow to white. They have a fairly square tail and the lower jaw sticks out past the upper.
Common "Cat" Names: polliwog, paperskin, mud, creek, bull, greaser, slick.
There are six species of bullheads. The six include the flat, snail, spotted, black, yellow, and brown. Where available, the black, yellow, and brown typically are the ones to grow to keeper size and can be found in large numbers.
Black bullheads have rounded anal fin with 17 to 21 rays. Yellow bullheads have a straight outer edge anal fin with 24 to 27 rays along with white chin barbels. The brown bullhead has a distinct brownish mottling over its body.
Common "Cat" Names: Potomac.
Whites can be difficult to identify because they have similar features to several other species. Proportions are similar to brown bullheads, the color similar to a blue, the tail not quite as deeply forked as the channel, and when over 10 pounds their mottled colors can fade to look like a channel. The identifier is the 19 to 23 anal fin rays and white chin barbels.