The scientific name for catfish is Siluriformes, and they are a diverse group of ray-finned fish found all throughout the world. Catfish are of the bottom-feeding variety of fish and can be found in coastal regions and freshwater habitats.
Catfish belonging to the Siluriformes order have barbels on the sides of the mouth that resemble a cat's whiskers. There are more than 3,000 different species of catfish throughout the world, but it is possible that the number could be as high as 4,500. Most catfish live in freshwater environments, but some have actually adapted to living in shallow saltwater environments or caves. Catfish can be as short as .4 inches in length or as long as 106 inches, depending on what region or area of the world in which the catfish is found.