Erethistidae are a family of

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) 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 ...

es that originate from southern

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

. It includes about 45 species.

Taxonomy

This family includes species previously placed in

Sisoridae 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. Taxonomy The family Sisoridae is recog ...

. They were removed because they were thought to be more closely related to the neotropical

Aspredinidae The Aspredinidae are a small South American family of catfishes (order Siluriformes) also known as the banjo catfishes, with about 43 species. Distribution Aspredinids are found throughout the major tropical rivers of South America (e.g., Magda ...

than to the remaining sisorids due to a number of morphological characters. However, it has been suggested that the erethistid catfishes be included back into Sisoridae and some genera are included in that family by some authorities.

Distribution

Erethistids are found on the

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

n subcontinent eastwards to western

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...

and northern Malay Peninsula.

Description

Many of the members of this family are small, cryptically colored fishes with tuberculate skin. Erethistids are distinguished from sisorids by having a

pectoral girdle The shoulder girdle or pectoral girdle is the set of bones in the appendicular skeleton which connects to the arm on each side. In humans it consists of the clavicle and scapula; in those species with three bones in the shoulder, it consists of ...

with a long

coracoid A coracoid (from Greek κόραξ, ''koraks'', raven) is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (marsupials and placentals). In therian mammals (including humans), a coracoid process is prese ...

process that extends well beyond the base of the

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

; this structure can be felt through the skin in all genera and is visible externally in all genera except '' Pseudolaguvia''. Erethistids differ from amblicipitids in that they lack a cuplike fold of skin in front of the pectoral fin (vs. possessing the cuplike fold), and have a dorsal fin with a strong spine and no thick covering of skin (vs. a weak spine with a thick covering of skin). Erethistids have nostrils close together, separated by a nasal

barbel Barbel may refer to: *Barbel (anatomy), a whisker-like organ near the mouth found in some fish (notably catfish, loaches and cyprinids) and turtles *Barbel (fish), a common name for certain species of fish **''Barbus barbus'', a species of cyprinid ...

, which differs from akysids which have widely separated nostrils on each side of the head, with a barbel on the posterior nostril. Some erethistids possess a

thoracic The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the crea ...

adhesive apparatus formed by longitudinal skin folds densely covered with unculi that appears to be an adaptation to life in fast flowing waters; this closely resembles a similar structure in the sisorid ''

Glyptothorax ''Glyptothorax'' is a genus of catfishes order Siluriformes of the family Sisoridae. It is the most species-rich and widely distributed genus in the family with new species being discovered on a regular basis. These species are distributed in the ...

''.

References

{{Taxonbar, from=Q141902 Catfish families Fish of South Asia Taxa named by Pieter Bleeker