Catfish 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 three largest species alive, the Mekong giant catfish from Southeast Asia, the wels catfish of Eurasia, and the piraíba of South America, to detritivores, and even to a tiny parasitic species commonly called the candiru, Vandellia cirrhosa. Neither the armour-plated types nor the naked types have scales. Despite their name, not all catfish have prominent barbels or "whiskers". 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. Many catfish are nocturnal, but others are crepuscular or diurnal.
The hillstream loaches or river loaches are a family, the Balitoridae, of small fish from South, Southeast and East Asia. The family includes about 202 species. They are sometimes sold as "lizardfish" or "flossensaugers". Many of the species are popular for aquaria, species in the genus Sewellia are most commonly sold in the aquaria trade. They have a number of similarities with the Cobitidae, their sibling family of "loaches", such as multiple barbels around the mouth. They should not be confused with the loricariids, which look similar but are a family of catfish.
Callichthyidae is a family of catfishes, called armored catfishes due to the two rows of bony plates along the lengths of their bodies. It contains some of the most popular freshwater aquarium fish, such as many species in the genus Corydoras.
The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about 7,000,000 km2 (2,700,000 sq mi), or about 35.5 percent of the South American continent. It is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname, and Venezuela, as well as the territory of French Guiana.
The Claroteidae are a family of catfish found in Africa. This family was separated from Bagridae. However, the monophyly of the family is sometimes contested.
Loricariidae is the largest family of catfish, with over 90 genera and just over 680 species. Loricariids originate from freshwater habitats of Costa Rica, Panama, and tropical and subtropical South America. These fish are noted for the bony plates covering their bodies and their suckermouths. Several genera are sold as "plecos", notably the suckermouth catfish, Hypostomus plecostomus, and are popular as aquarium fish.
The walking catfish is a species of freshwater airbreathing catfish native to Southeast Asia. It is named for its ability to "walk" and wiggle across dry land, to find food or suitable environments. While it does not truly walk as most bipeds or quadrupeds do, it can use its pectoral fins to keep it upright as it makes a wiggling motion with snakelike movements to traverse land. This fish normally lives in slow-moving and often stagnant waters in ponds, swamps, streams, and rivers, as well as in flooded rice paddies, or temporary pools that may dry up. When this happens, its "walking" skill allows the fish to move to other aquatic environments. Considerable taxonomic confusion surrounds this species and it has frequently been confused with other close relatives. One main distinction between the walking catfish and the native North American ictalurid catfish with which it sometimes is confused, is that the walking catfish lacks an adipose fin. It can survive 18 hours out of water.
Trichomycteridae is a family of catfishes commonly known as pencil catfishes or parasitic catfishes. This family includes the candiru fish, feared by some people for its alleged habit of entering into the urethra of humans. They are one of the few parasitic chordates. Another species is the life monsefuano which was important to the Moche culture and still an important part of Peruvian cuisine.
The Pimelodidae, commonly known as the long-whiskered catfishes, are a family of catfishes.
The Aspredinidae are a small South American family of catfishes also known as the banjo catfishes, with about 43 species.
The Ariidae or ariid catfish are a family of catfish that mainly live in marine waters with many freshwater and brackish water species. They are found worldwide in tropical to warm temperate zones. The family includes about 143 species.
The Bagridae are a family of catfish that are native to Africa (Bagrus) and Asia from Japan to Borneo. It includes about 245 species. These fish are commonly known as naked catfishes or bagrid catfishes.
Sisoridae is a family of catfishes. These Asian catfishes live in fast-moving waters and often have adaptations that allow them to adhere to objects in their habitats. The family includes about 235 species.
Horabagrus is a genus of catfish in the family Horabagridae endemic to rivers in the Western Ghats in Kerala and Karnataka, India. H. brachysoma is an important food fish and members of this genus can be found in the aquarium trade.
The Hypostominae are a subfamily of catfishes of the family Loricariidae. Most members are restricted to tropical and subtropical South America, but there are also several species in southern Central America. Hypostomus plecostomus, which is popular in the aquarium trade, has been introduced to several regions far from its native range.
Ancistrini is a tribe of catfishes of the family Loricariidae. Most are restricted to tropical and subtropical South America, but there are also several genus in southern Central America.
Doumea is a genus of loach catfishes native to Africa.
Congoglanis is a genus of loach catfishes found in the Congo River system of Africa. This genus is considered the sister group of all other species in the subfamily Doumeinae.
Amphiliinae is one of three subfamilies of the loach catfish family Amphiliidae, it consists of two genera, Amphilius and Paramphilius and is endemic to the Afrotropics. There are currently 29 species classified as members of the Amphiliinae, some of which are traded as part of the aquarium trade. They are small catfish measuring between 95mm and 195mm.
is one of three subfamilies of the loach catfish family Amphiliidae, it consists of five genera endemic to the Afrotropics which contain a total of 28 currently recognised species. They are small catfish measuring between 20mm and 80mm.
