''Exostoma'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

sisorid catfish 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 ...

es native to

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 ...

. These species are distributed in the

Brahmaputra The Brahmaputra is a trans-boundary river which flows through Tibet, northeast India, and Bangladesh. It is also known as the Yarlung Tsangpo in Tibetan, the Siang/Dihang River in Arunachali, Luit in Assamese, and Jamuna River in Bangla. I ...

drainage of northeast

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 ...

, and east and south to the

Salween , ''Mae Nam Salawin'' ( , name_etymology = , image = Sweet_View_of_Salween_River_in_Tang_Yan_Township,_Shan_State,_Myanmar.jpg , image_size = , image_caption = Salween River in Shan State, Myanmar , map ...

drainages in

Burma Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...

. ''E. berdmorei'' is found in the Sittang and Salween drainages in Burma. ''E. labiatum'' is known from the Brahmaputra drainage in northeast India, but has also been recorded in the Salween drainage in Burma, the Ayeyarwady drainage in China, and the Brahmaputra drainage in

Tibet Tibet (; ''Böd''; ) is a region in East Asia, covering much of the Tibetan Plateau and spanning about . It is the traditional homeland of the Tibetan people. Also resident on the plateau are some other ethnic groups such as Monpa people, ...

and Burma. ''E. stuarti'' is from the Ayeyarwady River of Burma and India; however, it has not been collected since its original discovery. ''E. labiatum'' is found in mountain rapids. In a 2007 checklist of sisorid and erethistid catfishes, Thomson lists ''E. stuarti'' and ''E. vinciguerrae'' as valid species. In a 2007 checklist of catfishes, Ferraris lists these two species as species inquerendae, noting that these species are either treated as valid or as

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are al ...

s of ''E. labiatum''.

Species

These are the currently recognized species in this genus: * ''

Exostoma barakensis ''Exostoma barakensis'' is a species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which a ...

'' Vishwanath & Joyshree, 2007 * ''

Exostoma berdmorei ''Exostoma berdmorei'' is a species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which an ...

Blyth Blyth may refer to: People * Blyth (surname) * Blythe (given name) Places Australia * Blyth, South Australia, a small town Canada * Blyth, Ontario, a village United Kingdom * Blyth, Northumberland, a town ** Blyth Valley (UK Parliament ...

, 1860 * ''

Exostoma effrenum ''Exostoma effrenum'' is a species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any ...

'' H. H. Ng & Vidthayanon, 2014 Ng, H.H. & Vidthayanon, C. (2014): A review of the glyptosternine catfish genus ''Exostoma'' Blyth 1860 from Thailand, with descriptions of two new species (Teleostei: Siluriformes). ''Zootaxa, 3869 (4): 420–434.'' * ''

Exostoma labiatum ''Exostoma labiatum'', the Burmese bat catfish, is a species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group ...

'' ( McClelland, 1842) (Burmese Bat Catfish) * ''

Exostoma laticaudata ''Exostoma laticaudata'' is a species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which ...

'' Arunkumar, 2020Arunkumar L. Exostoma laticaudata, a new glyptosternine catfish (Teleostei: Sisoridae) from Manipur, Northeastern India. Species, 2020, 21(68), 293-305 * ''

Exostoma peregrinator ''Exostoma peregrinator'' is a species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which ...

'' H. H. Ng & Vidthayanon, 2014 * ''

Exostoma sawmteai ''Exostoma sawmteai'' is a species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any ...

'' Lalramliana, Lalronunga, Lalnuntluanga & H. H. Ng, 2015 Lalramliana, Lalronunga, S., Lalnuntluanga & Ng, H.H. (2015): ''Exostoma sawmteai'', a new sisorid catfish from northeast India (Teleostei: Sisoridae). ''Ichthyological Exploration of Freshwaters, 26 (1): 59-64.'' * ''

Exostoma stuarti ''Exostoma stuarti'' is a species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any ...

'' (

Hora Hora may refer to: Companies * Hora (company), a Romanian manufacturer of stringed musical instruments People * Hora (surname) * Hora (musician), member of the Japanese duo Schwarz Stein * Hora people, an indigenous people of Bolivia Places * ...

, 1923) * ''

Exostoma tenuicaudata ''Exostoma tenuicaudata'' is a species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which ...

Tamang The Tamang (; Devanagari: तामाङ; ''tāmāṅ'') are an Tibeto-Burmese ethnic group of Nepal. In Nepal Tamang/Moormi people constitute 5.6% of the Nepalese population at over 1.3 million in 2001, increasing to 1,539,830 as of the 2011 ...

, Sinha & Gurumayum, 2015 Tamang, L., Sinha, B. & Gurumayum, S.D. (2015): ''Exostoma tenuicaudata'', a new species of glyptosternine catfish (Siluriformes: Sisoridae) from the upper Brahmaputra drainage, northeastern India. ''Zootaxa, 4048 (3): 441–445.'' * '' Exostoma vinciguerrae''

Regan The family name Regan, along with its cognates O'Regan, O Regan, Reagan, and O'Reagan, is an Anglicized form of the Irish surname Ó Riagáin or Ó Ríogáin, from Ua Riagáin. The meaning is likely to have originated in ancient Gaelic ''ri' ...

, 1905

Description

''Exostoma'' is distinguished by having a continuous groove behind the lips (post-labial groove), the

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they ar ...

openings not extending onto the underside (venter),

homodont In anatomy, a heterodont (from Greek, meaning 'different teeth') is an animal which possesses more than a single tooth morphology. In vertebrates, heterodont pertains to animals where teeth are differentiated into different forms. For example ...

dentition of oar-shaped, distally flattened teeth in both jaws, the tooth patches separated in upper jaw, and 10–11 branched pectoral rays. The head is depressed with a broadly rounded snout. The body is elongate and flattened ventrally to the

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two e ...

s. The eyes are minute, dorsally located, and under the skin (subcutaneous). The lips are thick, fleshy, and papillated. The teeth are small to large, moveable, oar-shaped, flattened distally and directed posteriorly in distinct patches. ''E. stuarti'' is recorded to grow to 5.6 centimetres (2.2 in) SL. ''E. berdmorei'' and ''E. labiatum'' grow to about 10–11 cm (3.94–4.33 in) TL.

References

{{Taxonbar, from=Q5420691 Sisoridae Fish of South Asia Fish of Myanmar Fish of China Fish of India Freshwater fish genera Catfish genera Taxa named by Edward Blyth