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.
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.
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 Doradidae are a family of catfishes also known as thorny catfishes, raphael catfishes or talking catfishes. These fish are native to South America, primarily the Amazon basin and the Guianas.
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.
The loach catfishes are a family, Amphiliidae, of catfishes. They are widespread in tropical Africa, but are most common in streams at high elevations; most species are able to cling to rocks in fast-flowing streams. The 13 genera contain 68 species.
Hemiancistrus is a genus of suckermouth armored catfishes. These species are native to South America. The taxonomy of this genus is complex and unclear, and major work has to be done. Many of these fish are popular aquarium fish.
Horabagrus brachysoma or the sun catfish is a species of catfish endemic to rivers in the Western Ghats of India. It is known as Günther's catfish or yellow catfish. It is also known as Manjakoori in its native range. It is also known by a host of other names, such as bullseye catfish, golden red tail catfish and solar catfish.
Horabagrus nigricollaris is a species of catfish endemic to India. It is also known as the "Black collared catfish". It is found only in the Chalakudy River in Kerala, India. This species is an inhabitant of hill streams.
Farlowella is a genus of fish in the family Loricariidae native to South America. This genus is broadly distributed in Amazon, Orinoco, Paraná and coastal rivers of the Guyana Shield. It is absent from the Pacific slope of the Andes and from the coastal rivers of the Brazilian Shield. Many of these species are kept in aquariums. This genus has a unique body shape that resembles a thin stick of wood. The body is slender and elongate, often with a pronounced rostrum and a brownish color with two lateral dark stripes beginning at the tip of the rostrum, passing over the eyes and ending at the tail, which are periodically interrupted on the caudal peduncle.
Mystus is a genus of fish in the family Bagridae native to Asia. Phylogenetic relationships within this genus are poorly understood, though it has been suggested that there are two major lineages.
Olyra is a genus of catfishes of the family Bagridae. This genus occurs throughout South Asia and western Indochina, from India to western Thailand.
Pseudobagrus is a genus of bagrid catfishes that inhabit streams and rivers throughout East Asia. About half of these species occur in China.
Pseudomystus is a genus of catfishes of the family Bagridae.
Liobagrus is a genus of catfishes of the family Amblycipitidae. Liobagrus fishes are distributed in the Yangtze River basin, Taiwan, Japan, and the Korea Peninsula. The adipose fin of these fishes is a confluent with the caudal fin. The nostrils are far apart, unlike those found in Amblyceps. Most Liobagrus species grow to about 100 millimetres (3.94 in) SL.
Pseudeutropius is a genus of catfishes conventionally placed in the family Schilbeidae but recent work has suggested it be placed in the newer family Horabagridae, the genus is native to Asia.
Horabagridae is a proposed family of catfishes containing three genera, Horabagrus, Platytropius and Pseudeutropius. Horobagrus has been more usually assigned to the family Bagridae and sometimes it has been suggested it is closer to the Schilbeidae which is where the other two genera have been more conventionally placed.
