Sisoridae

Genera ''), the largest member of the family The subfamily placement is based on ''Eschmeyer's Catalog of Fishes'': • Subfamily Sisorinae Bleeker, 1858 • Ayarnangra Roberts, 2001 • Bagarius Bleeker, 1853 • Caelatoglanis Ng & Kottelat, 2005 • Conta Hora, 1950 • Erethistes Müller & Troschel, 1849 • Erethistoides Hora, 1950 • Gagata Bleeker, 1858 • Glyptothorax Blyth, 1860 • Gogangra Roberts, 2001 • Nangra Day, 1877 • Pseudolaguvia Misra, 1976 • Sisor Hamilton, 1822 • Subfamily Glyptosterninae Gill, 1861 • Barbeuchiloglanis Li, Dao & Zhou, 2022 • Chimarrichthys Sauvage, 1874 • Creteuchiloglanis W. Zhou, X. Li & A. W. Thomson, 2011 • Exostoma Blyth, 1860 • Glaridoglanis Norman, 1925 • Glyptosternon McClelland, 1842 • Myersglanis Hora & Silas, 1952 • Oreoglanis Smith, 1933 • Parachiloglanis X. W. Wu, M. J. He & X. L. Chu, 1981 • Pareuchiloglanis Pellegrin, 1936 • Pseudecheneis Blyth, 1860 • Pseudexostoma Chu, 1979 • Sineuchiloglanis Li, Dao & Zhou, 2022 • Tremeuchiloglanis Li, Dao & Zhou, 2022 Systematics '' are unusually flattened as an adaptation for fast-flowing steams The family Sisoridae is recognized as a natural, monophyletic group based on morphological and molecular evidence. Evidence from a 2007 molecular analysis supports polyphyly of Pareuchiloglanis. Glaridoglanis might be a basal member of the tribe Glyptosternina. Pseudecheneis may be placed in the tribe Glyptosternina, but its sister-group relationship between it and the monophyletic glyptosternoids cannot be rejected. In the past, certain members of the Sisorinae were placed in their own family, Erethistidae, because they were thought to be closely related to the neotropical Aspredinidae than to the remaining sisorids due to a number of morphological characters. However, phylogenetic analyses have reaffirmed that the species classified in the Erethistidae are actually placed within the Sisorinae. ==Distribution==

Sisorids inhabit freshwater and originate from southern Asia, from Turkey and Syria to South China and Borneo, primarily in the Oriental region. Glyptosterninae is distributed from the Caucasus to China. Most glyptosternine genera are found in China, with the exception of Myersglanis. Sisorids are mostly small forms inhabit mountain streams. ==Fossil record and biogeography==

The oldest known sisorid fossil is B. bagarius found in Sumatra and India of the Pliocene. ==Description==

Most of these fish have four pairs of barbels and a large adipose fin. The maximum size is 2 metres. Some genera have a pectoral girdle with a long coracoid process that extends well beyond the base of the pectoral fin; this structure can be felt through the skin in all genera and is visible externally in all genera except Pseudolaguvia. This was previously used to differentiate sisorids from erethistids when they were considered distinct families. They differ from amblycipitids 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). They have nostrils close together, separated by a nasal barbel, which differs from akysids which have widely separated nostrils on each side of the head with a barbel on the posterior nostril. Some possess a thoracic 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. ==References==