Catfish is a collective name for a large group of fish which can be found all over the world in marine and freshwater environments. The fish occupies a number of ecological niches, from invasive pest to farmed fish species to popular fish tank pet. They are also eaten and fished for sport, providing a dense white meat which can sometimes be very flavorful, especially if taken from clean water. The flesh is very sturdy, and stands up well to frying and grilling, two popular preparations in the Southern United States.
Most members of the catfish families have distinctive barbels or whiskers which lend the fish its name. The whiskers range from long and dragging to quite short, and are positioned on either side of the large round mouth, which is carried low in the face of the fish. Additionally, catfish do not have scales, although some have bony plates which can be mistaken for single scales. They have forked tails and broad fan like fins which are usually located forward on the body.
Catfish are bottom dwelling fish, and prefer gravelly environments. They are omnivorous, and as a result are often viewed as pests when they are introduced. These fish can be disruptive to environments where they are not native, uprooting aquatic plants and established fish species. Several European nations introduced them to their waterways and have been dismayed by the result of increased competition with native species.
Catfish can get quite large, with some captured specimens being bigger than their captors. Some people find the snub face of the fish somewhat endearing, while other fishermen say that the fish is rather ugly, and some parts of the world have extensive folklore surrounding the catfish. In any case, it is one of the most profitably farmed fish in the United States, with a huge aquaculture market for the fish taking off in the 1980s. Most available for commercial sale is farmed, although anglers do go after the fish for sport and dinner in lakes and streams all over the world.
These fish are also sold to be kept in fish tanks, where they keep the sides of the tank along with the floor gravel clean. When selecting fish for this purpose, consumers should be aware that they will eat smaller fish, and that they can grow substantially in size. Many species will quickly outgrow small fish tanks. In addition, sharp gravel can damage the mouth or lower body of the catfish.