Monotypic fish genera

The Pacific barreleye fish (Macropinna) is a genus of ray-finned fish belonging to Opisthoproctidae, the barreleye family. It contains one species, M. microstoma. It is recognized for a highly unusual transparent, fluid-filled shield on its head, through which the lenses of its eyes can be seen. It was originally believed that the tubular eyes of this fish were fixed in place, offering only tunnel vision above its head. However, in 2008, scientists discovered that its eyes were able to rotate both up and forward with its transparent dome. This feature allows for M. microstoma to observe prey w

right|thumb|Brosme for sale at the fish market in Bergen, Norway, in 2012 The cusk (Brosme brosme) is a North Atlantic cod-like fish in the ling family Lotidae. It is the only species in the genus Brosme. Its other common names include European cusk, tusk, torsk, brosmius and moonfish.

Disymphia molitorella (mud carp or dace) is a species of ray-finned fish in a monospecific genus found mainly in southern China and Vietnam.

Theraps is a genus of cichlid fish that includes only a single species, the Arroya cichlid (Theraps irregularis) from fast-flowing rivers and streams in the Usumacinta and Polochic basins of southern Mexico and Guatemala. It is a medium-sized cichlid, up to in standard length.

Eremophilus is a monospecific genus of freshwater ray-finned fish belonging to the family Trichomycteridae, the pencil and parasitic catfishes, the only species in the genus is Eremophilus mutisii. This fish grows to about 30 centimetres (12 in) and originates from the Bogotá River basin, which is a tributary of the Magdalena River. It has probably been introduced to Ubaté, Chiquinquirá, and Tundama valleys, Colombia.

REDIRECT Haplotaxodon microlepis

species of fish

Konosirus punctatus is a species of fish in the family Dorosomatidae. It is the only member of the monotypic genus Konosirus. Its common names include dotted gizzard shad and konoshiro gizzard shad. It is native to the northwestern Pacific Ocean, where it occurs along the Asian coastline.

Hypsophrys is a monospecific genus of freshwater ray-finned fish belonging to the family Cichlidae, the cichlids. The only species in this genus is Hypsophrys unimaculatus, the moga, butterfly cichlid, macaw cichlid, parrot cichlid or Nicaragua cichlid, a fish found on the Atlantic slope of Central America.

thumb|right|240px|Haplophryne mollis female anglerfish with atrophied males attached

Velifer is an Indo-Pacific genus of ray-finned fishes in the family Veliferidae. It is monotypic, being represented by the single species Velifer hypselopterus, the sailfin velifer. This species grows to a length of total length and is of minor importance in commercial fisheries.

Metavelifer is a genus of fishes in the family Veliferidae. It is monotypic, being represented by the single species Metavelifer multiradiatus, commonly known as the spinyfin velifer. It grows to a length of TL and is found in the Indian and Pacific Oceans. left|thumb|1913 illustration

REDIRECT Gnathochromis permaxillaris

Monopenchelys acuta, the redface moray or redface eel, is a species of saltwater eel, the only member of the genus Monopenchelys of the Muraenidae (Moray eel) family. It is found in the Atlantic, the eastern Pacific, and the western Indian Ocean. Its length is up to .

Speonectes tiomanensis is a species of stone loach that is endemic to Malaysia and only known from a cave on Tioman Island. This fish reaches a length of SL. This species is the only known member of its genus, but it was formerly included in Sundoreonectes. It is the only cavefish known from Malaysia.

REDIRECT Boxlip mullet

Orthroleucos is a monospecific genus of freshwater ray-finned fish belonging to the family Leuciscidae, which includes the daces, Eurasian minnows and related species. The only species in the genus is Orthroleucos atropatenus, also known as the Azerbaijani spring roach or Shirvan roachling. This species is endemic to Azerbaijan.

Astyanacinus is a monospecific genus of freshwater ray-finned fish belonging to the family Acestrorhamphidae, the American characins. The only species in the genus is Astyanacinus moorii which is found in the Upper Paraguay River basin in Bolivia and Brazil. The specific name honours the English botanist Spencer Moore who collected the holotype.

Gosztonyia is a monospecific genus of marine ray-finned fish belonging to the family Zoarcidae, the eelpouts. The only species in the genus is Gosztonyia antarctica which is known only from the Bellingshausen Sea of Antarctica.

REDIRECT Japanese gissu

Dinichthys (from , 'terrible' and 'fish') is an extinct monospecific genus of large marine arthrodire placoderm from the Late Devonian (Famennian stage) measuring around long. Fossils were recovered from the Ohio Shale Formation along the Olentangy River in Delaware County, Ohio.

Neoeucirrhichthys maydelli, the Goalpara loach, is a species of loach found in Assam, India, and possibly in Bangladesh. It is the only member of its genus.

The warrior catfish (Aceroichthys dioctes) is a species of catfish in the family Ariidae. It was described by Patricia J. Kailola in 2000, originally under the genus Arius. It inhabits marine and freshwaters in New Guinea and Australia. It reaches a standard length of , and a maximum weight of .

REDIRECT Lithoxus lithoides

Brevidens is a monospecific genus of freshwater ray-finned fish belonging to the family Anostomidae, the toothed headstanders. The only species in this genus is Brevidens striatus, a fish found in tropical South America.

Stenolicmus is a monospecific genus of freshwater ray-finned fish belonging to the family Trichomycteridae and the subfamily Sarcoglanidinae, the psammmophilic catfishes, the only species in the genus is Stenolicmus sarmientoi, a species endemic to Bolivia where it is found in the upper Apere River basin. This species grows to a length of NG.

Parachaetodon is a monotypic genus of butterflyfishes, the only species being the sixspine butterflyfish (Parachaetodon ocellatus), which is also known as the ocellate butterflyfish or eyespot butterflyfish. is a species of butterflyfish native to tropical reefs of the eastern Indian Ocean and the western Pacific Ocean.

Stellantia siderea is a species of armored catfish known only from the upper Orinoco basin in Amazonas state, Venezuela. It is the only member of the monospecific genus Stellantia, which forms a tribe with its also monotypic sister genus Colossimystax.

REDIRECT Ophiogobius jenynsi

Roeboexodon is a monospecific genus of freshwater ray-finned fish belonging to the family Characidae, within the subfamily Exodontinae, the toothy or lepidiphagous characins. The only species in this genus is Roeboexodon guyanensis, a species which is found in South America where it occurs in clear water rivers with sandy bottoms in Brazil, French Guiana and Suriname. This lepidophagous species has a maximum standard length of .

Zungaropsis is a genus of catfish (order Siluriformes) in the family Pimelodidae. It is a monotypic genus, containing only the single species Zungaropsis multimaculatus, and is considered to be closely related to the genus Zungaro. In 2003, Zungaropsis was considered as a genus inquirendum of the Pimelodidae.

Bleekeriella leptaspis, the triangular shield catfish, boofhead catfish, freshwater forked tailed catfish, salmon catfish, or lesser salmon catfish, is a monospecific genus of catfish in the family Ariidae. It was described by Pieter Bleeker in 1862, originally under the genus Hexanematichthys. It inhabits marine, brackish and freshwaters in Australia and New Guinea, at a maximum known depth of . It reaches a maximum standard length of .

Kyataphisa is a monospecific genus of sea catfish in the subfamily Ariinae. Its only species, K. nenga (commonly known as kata) is found in the Arabian Sea, the Bay of Bengal and the Pacific Ocean off Thailand. It is found in marine as well as brackish waters, and reaches a maximum length of .

The Taiwanese barbel moray, Cirrimaxilla formosa, is a species of moray eel in the family Muraenidae, and the only member of the genus Cirrimaxilla. It was described by Hong Ming Chen and K. T. Shao in 1995. It is found only in Pingtung County, Taiwan. The holotype, a female, measures a total length of .

Cinetodus is a genus of sea catfishes (order Siluriformes) of the family Ariidae. This species originates from brackish and fresh waters of Irian Jaya, southern New Guinea and northern Australia.

Heminodus is a genus of marine ray-finned fish belonging to the subfamily Peristediinae, the armoured gurnards or armored sea robins. It is currently considered to be a monotypic genus, its only species being Heminodus philippinus.

Colossimystax pectegenitor is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the main channel of the Orinoco near the mouth of the Ventuari River, as well as in the Casiquiare canal. The species is usually found in areas with flowing water near large rocky outcrops. It reaches SL. It is the only member of the monospecific genus Colossimystax, which forms a tribe with its also monotypic sister genus Stellantia.

Malayochela is a monospecific genus of freshwater ray-finned fish belonging to the family Danionidae, the danios or danionins. The only species in the genus is Malayochela maassi, a fish found in Peninsular Malaysia, Sumatra and Kalimantan

Pherallodus is an Indo-Pacific genus of clingfishes from the family Gobiesocidae. The only recognized species in this genus is Pherallodus indicus, described by M. C. W. Weber in 1913 as Crepidogaster indicus, but as this was preoccupied it was later moved to Lepadichthys.

Neosalangichthys ishikawae, the Ishikawa icefish, is a species of Salangidae that is endemic to marine waters near the coast in northern Honshu, Japan. Originally placed in the genus Salangichthys, the species was assigned in 2012 to the monotypic genus Neosalangichthys. Adults stay in relatively shallow open marine waters, but larve and immatures typically stay off beaches, often in the surf zone, in waters that range from marine to brackish. Unlike the more widespread S. microdon with which it often occurs, N. ishikawae does not occur in fresh water.

Gephyromochlus is a monospecific genus of driftwood catfish in the family Auchenipteridae. It is found in the coastal rivers of the Guianas in South America. Its only species is Gephyromochlus leopardus.

Eleutherochir is a monotypic genus of dragonets native to the Indian Ocean and the western Pacific Ocean.

REDIRECT Hexanematichthys sagor

Nedystoma is a monospecific genus of sea catfishes endemic to the island of New Guinea where they are found in fresh and brackish waters in both the Indonesian portion and in Papua New Guinea. There is currently only one described species in this genus.

Allips concolor is a species of eel in the family Ophichthidae. The only member of its genus, it is found in the eastern Indian Ocean in shallow waters around Thailand and Australia.

Nemapteryx is a genus of sea catfishes found mostly in coastal marine and brackish waters from South Asia to Australia. There is currently only one described species in this genus.

Ctenoscopelus is a monotypic genus of lanternfish, family Myctophidae. The sole species is Ctenoscopelus phengodes, the bright lanternfish. It occurs in the Atlantic, Indian, and Pacific Oceans on the southern hemisphere. It can grow to standard length.

REDIRECT Transparent goby

Cunningtonia longiventralis is a species of cichlid endemic to Lake Tanganyika in East Africa where it is found near rocky shores. It eats floating plankton. This species reaches a length of TL. It can also be found in the aquarium trade. it is the only known member of its genus. The generic name honours the British zoologist and anthropologist William Alfred Cunnington (1877-1958), the leader of the expedition to Lake Tanganyika during which type was collected.

REDIRECT Distocyclus conirostris

Ophthalmolebias ilheusensis is a killifish from the family Rivulidae which is endemic to Brazil where it is only known from river floodplains near Ilhéus in Bahia. Fishbase has this as the only species in the genus Opthamolebias with the other five species which other authorities classify as being within that genus placed in Simpsonichthys. The genus Ophthalmolebias was initially considered a subgenus of Simpsonichthys, but has been elevated to full genus status.

Minyclupeoides dentibranchialus is an extremely small fish () found only in the Mekong Basin in Cambodia. It is the only species in its genus.

Synaptolaemus is a monospecific genus of freshwater ray-finned fish belonging to the family Anostomidae, the toothed headstanders. The only species in the genus is Synaptolaemus latofasciatus, a species found in South America.

Pararasbora is a monospecific genus of freshwater ray-finned fish belonging to the family Xenocyprididae, the East Asian minnows or sharpbellies. The only species in the genus is Pararasbora moltrechti, '''Moltrecht's minnow'. This species is endemic to Taiwan. It was formerly considered to be a species in the genus Aphyocypris''. The Endemic Species Research Institute under the Council of Agriculture of the Executive Yuan in Taiwan has listed this species as a "precious and rare species" among other endemic freshwater species.

Lipolagus ochotensis, the eared blacksmelt, is a species of deep-sea smelt found in the Pacific Ocean down to depths of . This species grows to a length of .

Platytropius is a genus of schilbid catfishes native to Asia. All species are now considered to be extinct.

Ladigesia is monospecific genus of freshwater ray-finned fish belonging to the family Alestidae, the African tetras. The only species in the genus is Ladigesia roloffi, the Sierra Leone dwarf characin, is a species that is found in Sierra Leone and Liberia, Africa. The fish was named in honor of German aquarist Erhard Roloff (1903–1980), who collected the type specimen. They are a social species generally living in schools at mid depths and surface level fresh water. It lives for five years. Ninety-seven percent of their natural habitat has been lost.

Xenophthalmichthys danae is a species of pencil smelt found in deep waters to . This species has been found in the western Pacific Ocean and the Atlantic Ocean and is suspected to be circumtropical. This species grows to a length of SL.

Lethotremus is a monospecific genus of marine ray-finned fish belonging to the family Cyclopteridae, the lumpfishes or lumpsuckers. This genus is found in the northern Pacific Ocean. Following a 2017 taxonomic review by Lee et al., the species Lethotremus awae was reclassified as a species of Eumicrotremus, leaving the genus monotypic with Lethotremus muticus as its only species. Also known as the docked snailfish (a somewhat misleading name as this species is not one of the true snailfish in the family Liparidae), is a species of lumpfish native to the Northeast Pacific. It is known from the

thumb | right | alt=Adults of Ossubtus xinguense: GEA 1973, (a) male, 202.7 mm SL; (b) female, 168.5 mm SL. Brazil, Rio Xingu, Volta Grande. | Adults of Ossubtus xinguense: GEA 1973, (a) male, 202.7 mm SL; (b) female, 168.5 mm SL. Brazil, Rio Xingu, Volta Grande. Ossubtus is a genus of fish in the family Serrasalmidae. It contains a single species, Ossubtus xinguense, the parrot pacu or eaglebeak pacu, The species is endemic to rapids in the Xingu River basin in the Brazilian Amazon. This vulnerable species is primarily a herbivore.