Catfish

Akysidae Amblycipitidae Amphiliidae Anchariidae Andinichthyidae 160 Ariidae Aspredinidae Astroblepidae Auchenipteridae Austroglanididae Bagridae Callichthyidae Cetopsidae Chacidae Clariidae Claroteidae Cranoglanididae Diplomystidae Doradidae Erethistidae Heptapteridae Hypsidoridae 160 Ictaluridae Lacantuniidae Loricariidae Malapteruridae Mochokidae Nematogenyiidae Pangasiidae Pimelodidae Plotosidae Pseudopimelodidae Schilbeidae Scoloplacidae Siluridae Sisoridae Trichomycteridae incertae sedis 160 160 Conorhynchos 160 160 Horabagrus 160 160 Phreatobius

Catfish order Siluriformes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores species that eat dead material on the bottom , and even to a tiny parasitic species commonly called the candiru, Vandellia cirrhosa. There are armour-plated types and also naked types, neither having scales. Despite their name, not all catfish have prominent barbels members of the Siluriformes order are defined by features of the skull and swimbladder. Catfish are of considerable commercial importance many of the larger species are farmed or fished for food. Many of the smaller species, particularly the genus Corydoras, are important in the aquarium hobby.

Extant catfish species live in inland or coastal waters of every continent except Antarctica. Catfish have inhabited all continents at one time or another. 1 Catfish are most diverse in tropical South America, Africa, and Asia. 2 More than half of all catfish species live in the Americas. They are the only ostariophysans that have entered freshwater habitats in Madagascar, Australia, and New Guinea.

They are found in freshwater environments of all kinds, though most inhabit shallow, running water. 3 Representatives of at least eight families are hypogean live underground with three families that are also troglobitic inhabiting caves . 4 5 One such species is Phreatobius cisternarum, known to live underground in phreatic habitats. 6 Numerous species from the families Ariidae and Plotosidae, and a few species from among the Aspredinidae and Bagridae, are found in salt water. 7

Most catfish are bottom feeders. In general, they are negatively buoyant, which means that they will usually sink rather than float due to a reduced gas bladder and a heavy, bony head. 3 Catfish have a variety of body shapes, though most have a cylindrical body with a flattened ventrum to allow for benthic feeding.

A flattened head allows for digging through the substrate as well as perhaps serving as a hydrofoil. Most have a mouth that can expand to a large size and contains no incisiform teeth catfish generally feed through suction or gulping rather than biting and cutting prey. 3 However, some families, notably Loricariidae and Astroblepidae, have a suckermouth that allows them to fasten themselves to objects in fast-moving water. Catfish also have a maxilla reduced to a support for barbels this means that they are unable to protrude their mouths as other fish such as carp.