Monotypic Actinopterygii genera

thumb|Salamanderfish observed in habitat, 2023 Lepidogalaxias salamandroides is a species of small freshwater fish of Western Australia. It is the only member of the family Lepidogalaxiidae and genus Lepidogalaxias. Common names for this fish include salamanderfish and Shannon mudminnow. Although it is not a lungfish, it resembles lungfish in several respects, including its ability to survive dry seasons by burrowing into the sand. It is on the IUCN Red List as Endangered.

The myaka (Myaka myaka) is a critically endangered species of cichlid endemic to Lake Barombi Mbo in western Cameroon. It prefers open, deeper waters where it feeds on phytoplankton and small insects, only venturing into shallower waters to spawn. This species can reach a length of SL. It is currently the only known species in the genus Myaka, but it is very close to Sarotherodon. The myaka is threatened because of pollution and sedimentation due to human activities. It is potentially also threatened by large emissions of carbon dioxide (CO2) from the lake's bottom (compare Lake Nyos), althoug

Anomalochromis is a genus of fish in the family Cichlidae, containing the single species Anomalochromis thomasi, the African butterfly cichlid. It is a small cichlid growing to a length of . The natural habitat of A. thomasi is Sierra Leone, Liberia, and Guinea, mainly in smaller streams. The fish are typically found in slightly acidic, oxygen-rich water with other West African cichlid genera such as Hemichromis and Pelvicachromis.

The golden otocinclus (Macrotocinclus affinis, formerly Otocinclus affinis) is one of the smallest known suckermouth catfish, often called a 'dwarf oto'. Endemic to Southeast Brazil, this herbivorous, rheophilic, bottom-feeder only grows to around in length. The close relatives of this small fish are often used for the purpose of controlling algae in small home aquariums, under the name Otocinclus affinis. In reality, they belong to the species O. vittatus, O. vestitus and O. macrospilus and O. huaorani. The real M. affinis is not present in the aquarium hobby.

Agonus is a monospecific genus of ray-finned fish belonging to the subfamily Agoninae in the family Agonidae. Its only species is Agonus cataphractus, commonly known as the hooknose, pogge or armed bullhead. This is a demersal fish found in the coastal waters of the northeastern Atlantic Ocean.

Aristochromis christyi is a species of fish in the family Cichlidae, which is endemic to Lake Malawi in Africa. It is the only known member of its genus.

Archocentrus is a genus of cichlid fish from Central America. It currently contains a single species, the flier cichlid (Archocentrus centrarchus), which is found in stagnant and slow-moving freshwater habitats such as lakes, ponds, ditches, swamps and rivers in Honduras, Nicaragua and Costa Rica. It is up to long and feeds on invertebrates and detritus.

Amarsipus is the sole genus in the bagless glassfish family, Amarsipidae. It contains the single species Amarsipus carlsbergi, the amarsipa, which is a small and slender fish that lives in equatorial parts of the Indian and Pacific Oceans. It is found at depths from . It reaches in standard length. Molecular phylogenetic analysis has placed this family in the order Scombriformes within Pelagiaria; however, relationships between many pelagiarian lineages are poorly resolved and the nearest relatives of Amarsipidae remain unclear.

Salangichthys microdon is a species of icefish found in Japan, Korea and the Russian Far East. With the recent removal of S. ishikawae to the genus Neosalangichthys this species is the only remaining member of the genus Salangichthys. This species grows to a total length of . Despite its small size, it is considered a food fish and caught in commercial fisheries.

Cyema is a monospecific genus of marine ray-finned fish belonging to the monotypic family Cyematidae. The only species in the genus is Cyema atrum, the arrow eel, bobtail eel, bobtail snipe eel or deepwater eel. This species has circumglobal distribution.

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.

Eumecichthys fiski, the unicorn crestfish or unicornfish, is a very rare, little-known species of crestfish in the family Lophotidae, and the only member of the genus Eumecichthys. It likely has a worldwide distribution, having been first discovered offshore of Kalk Bay, South Africa, and subsequently reported from the Sea of Japan, southwest Florida, Clarion Island off Mexico, Hawaii, and India. Reports from the Bering Sea are likely erroneous. It is found in the bathypelagic zone, at depths around 1,000 m (3,300 ft).

Boulengeromyrus is a monospecific genus of freshwater ray-finned fish belonging to the family Mormyridae, the elephantfishes. The only species in the genus is '''Knoepffler's elephantfish (Boulengeromyrus knoepffleri'''). It occurs only in the Ivindo River and the Ntem River basins of Gabon and Cameroon. It reaches a maximum length of about .

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

Lipogenys gillii, the blackfin tapirfish, is a species of spiny eel in the family Notacanthidae, the only member of its genus. It is a benthic deep-sea fish occurring along the eastern coast of North America and in the southwestern Pacific near Australia at depths from 400 to 2,000 m.

Genyomyrus is a monospecific genus of freshwater fish belonging to the family Mormyridae, the elephantfishes. The only species in the genus is Genyomyrus donnyi which is endemic to the Congo River. It reaches a length of about .

Chonerhinos is a monotypic genus of pufferfish, family Tetraodontidae. The only species is Chonerhinos naritus, the bronze pufferfish or yellow pufferfish. It is native to Southeast Asia, where it is mainly found in estuarine and coastal habitats. This species grows to a length of TL, but otherwise it generally resembles the smaller and more strictly freshwater Auriglobus pufferfish. This predatory species feeds on other fish, crustaceans (both crabs and shrimp) and snails.

Canthophrys is a genus of freshwater fish in the loach family, Cobitidae. It contains the sole species Canthophrys gongota, the gongota loach, which is found in South Asia.

REDIRECT Tubemouth

Novaculichthys taeniourus, also known as the rockmover wrasse, carpet wrasse, dragon wrasse, bar-cheeked wrasse, olive-scribbled wrasse or reindeer wrasse, is a species of wrasse mainly found in coral reefs and lagoons in the Indo-Pacific region. These include habitats in the Gulf of California to Panama; tropical Pacific Ocean islands including Hawaii; the Philippines, Indonesia and Australia; and the Indian Ocean to the east coast of Africa. The common name, "rockmover wrasse", comes from their behavior of upending small stones and reef fragments in search of prey. This species is the only k

Alepidomus evermanni is a freshwater species of silverside endemic to western Cuba. This species grows to in standard length. It is the only known member of its genus. This species was described as Atherina evermanni by Carl H. Eigenmann in 1903 with a type locality of San Cristobal, Cuba. The specific name honours the American ichthyologist Barton Warren Evermann (1853-1932).

Arctogadus glacialis, known also with ambiguous common names Arctic cod and polar cod, is an Arctic species of fish in the cod family Gadidae, related to the true cod (genus Gadus). Arctogadus glacialis is found in icy water. They grow to about 30 cm long, and are favorite food of narwhals and other arctic whales.

Isischthys is a monospecific genus of freshwater ray-finned fish belonging to the family Mormyridae, the elephantfishes. The only species in the genus is Isichthys henryi. It occurs in coastal river basins in West Africa, ranging as far southeast as the Kouilou-Niari River in Middle Africa. It reaches a length of about .

Leptagoniates is a monospecific genus of ray-finned fish belonging to the family Characidae. It contains the single species Leptagoniates steindachneri, which is found in the Amazon River basin in Ecuador and Peru.

Anostomoides is a monospecific genus of freshwater ray-finned fishes belonging to the family Anostomidae, the toothed headstanders. These fishes are found in South America.

Neomyxus leuciscus, the acute-jawed mullet, is a species of mullet found in the tropical west and central Pacific Ocean. It is the only species in the genus Neomyxus.

Jayaramichthys leptonotacanthus is a species of sea catfish in the family Ariidae. It was described by Pieter Bleeker in 1849. It is known from tropical brackish and marine waters in the western Pacific. It reaches a maximum total length of . It is the only species in the genus Jayaramichthys.

thumb | 220x124px | right Hemisalanx brachyrostralis is a species of icefish endemic to the Yangtze basin, China. It is the only known species in the genus Hemisalanx, after Hemisalanx prognathus was moved to genus Salanx. In a study of the five freshwater icefish species in the Yangtze, it was a relatively low-density species, being much less frequent than Neosalanx taihuensis and N. oligodontis, but more than Protosalanx hyalocranius and N. tangkahkeii. H. brachyrostralis reaches up to in total length.

Barnardichthys fulvomarginata, the lemon sole, is a species of sole endemic to the coasts of South Africa. This species is the only known member of its genus.

species of fish

Dolicholagus longirostris, the longsnout blacksmelt, is a species of deep-sea smelt found circumglobally in deep waters of the tropics and subtropics. It is found at depths of . This species grows to a length of .

Aphyocheirodon is a monospecific genus of freshwater ray-finned fish belonging to the family Cheirodontinae.

Abyssoberyx is a genus of pricklefish containing the single species Abyssoberyx levisquamosus. It is found in the northeast Atlantic Ocean at depths from , and in the Mariana Trench up to . This species grows to a length of SL.

REDIRECT Pseudambassis lala

Apistops is a monotypic genus of wasp scorpionfishes belonging to the subfamily Apistinae in the family Scorpaenidae, the scorpionfishes and their relatives. Its only species is the short-armed waspfish (Apistops caloundra), also known as the shortfinned waspfish or shortspine waspfish. This species is found in the Indian and Pacific waters from Papua New Guinea, the Arafura Sea and northwest Australia. It is a demersal fish found on the inshore area of the continental shelf at depths between . This species grows to a length of SL.

Apocryptes bato is a species of mudskipper native to India, Bangladesh and Myanmar where it can be found in tropical rivers, estuaries and coastal waters of the Indian Ocean. This species can reach a length of TL. It is of minor importance to local commercial fisheries. It is currently the only known member of its genus.

Amblystilbe is a monospecific genus of freshwater ray-finned fish belonging to the family Characidae. The only species in the genus is Amblystilbe howesi, a characin, which is found in the western Amazon basin in Bolivia, Brazil and Peru. This fish has a maximum standard length of .

Holoshesthes is a monospecific genus of freshwater ray-finned fish belonging to the family Characidae. The only species in this genus is Holoshesthes pequira, a characin, found in South America.

Melanolagus bericoides (the bigscale deep-sea smelt) is a species of deep-sea smelt, found in oceans such as the Atlantic, Indian, and Pacific. It is widely distributed in tropical and subtropical oceans to a depth of , and the species grows to a length of . Its original name is Scopelus bericoides Borodin 1929 and it belongs to the family Melanolagus Kobyliansky, 1986.

Cheimerius is a monospecific genus of marine ray-finned fish belonging to the family Sparidae, the seabreams and porgies. The only species in the genus is Cheimerius nufar, the santer seabream, santer or soldier, of the Indian Ocean.

Opisthoproctus soleatus is an argentiniform species of fish referred to as the barreleye, being the type genus and species of the family Opisthoproctidae. The species lives in most tropical seas, but is more common in the eastern Atlantic, from western Ireland to Mauritania and from Sierra Leone to Angola, and also in the South China Sea. O. soleatus can grow to a standard length of and usually live from about deep.

Bovitrigla is a monotypic genus of marine ray-finned fishes belonging to the family Triglidae, the gurnards and sea robins, one of two genera belonging to the subfamily Pterygotriglinae. Its only species, Bovitrigla acanthomoplate, is found in the western Pacific Ocean.

Iluocoetes is a monospecific genus of marine ray-finned fish belonging to the family Zoarcidae, the eelpouts. The only species in the genus is Iluocoetes fimbriatus. This species is found off southern South America, off Chile and Argentina, in the southeastern Pacific and southwestern Atlantic Oceans.

Planiloricaria is a monospecific genus of freshwater ray-finned fish belonging to the family Loricariidae, the suckermouth armored catfishes, and the subfamily Loricariinae, the mailed catfishes. The only species in the genus is Planiloricaria cryptodon.

Pholidophorus (from , 'horny scale' and , 'to bear') is an extinct genus of stem-teleost fish. Numerous species were assigned to this genus in the past, but only the type species Pholidophorus latiusculus, from the Late Triassic of Europe, is considered to be a valid member of the genus today.

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

Aulorhynchus is a monospecific genus of marine ray-finned fish belonging to the family Aulorhynchidae. Its only species is the tube-snout (Aulorhynchus flavidus) which is found off the western coast of North America.

Ioichthys kashkini is a species of barreleye known only from the Arabian Sea where it has been recovered from a depth of . It is also distributed more broadly across the western Indian ocean.

Insperanos is a monospecific genus of freshwater ray-finned fish belonging to the family Anostomidae, the toothed headstanders. The only species in this genus is Insperanos nattereri, which is found in the Rio Negro, Aleixo Lake, and the central Amazon basin in Brazil. It is the only member of the genus Insperanos. Prior to 2021, it was classified in the large genus Leporinus, but was moved to its own monotypic genus in 2021 after a phylogenetic analysis found it to represent an evolutionarily basal member of the subfamily. It is thought to be a relatively ancient genus, having diverged from t

Rhinosternarchus is a monospecific genus of freshwater ray-finned fish belonging to the family Sternopygidae, the glass knifefishes. The only species in the genus is Rhinosternarchus goajira. This fish is found in the Lake Maracaibo basin in Colombia and Venezuela. Until 2021, it was placed in the genus Eigenmannia, but phylogenetic studies found it to be a distinct lineage most closely related to Archolaemus.

Plesioptopoma curvidens is a species of armored catfish native to Brazil, where it is known to occur in the Rio Paraopeba, a tributary of the Rio São Francisco. It is the only species in the genus Plesioptopoma. This species reaches a maximum length of (SL).

Ophthalmolepis lineolata, the southern Maori wrasse, is a species of wrasse endemic to the Indian Ocean coastal waters of Australia. This species has been found at a minimum depth of . This species grows to in total length. This species is the only known member of its genus.

Ectodus descampsii is a species of cichlid fish endemic to Lake Tanganyika in East Africa where it prefers areas with substrates of coarse sand. It feeds on micro-organisms, algae and diatoms. This species reaches a length of TL. It is also found in the aquarium trade. It is currently the only known member of its genus. The specific name honours Capitaine Georges Descamps (1855-1938), a Belgian officer in the anti-slavery movement at Lake Tanganyika.

Gymnoscyphus ascitus is a small species of clingfish found in the Caribbean Sea (documented off of Cuba (Jardines del Rey archipelago), Cozumel and St. Vincent) at depths of . This species is the only known member of the genus Gymnoscyphus.

Aulonocranus dewindti is a species of cichlid endemic to Lake Tanganyika and some rivers which flow into it.

Chilochromis duponti is a species of cichlid endemic to riverine habitats in the Chiloango River basin of Cabinda Province of Angola and the Democratic Republic of the Congo, the Kouilou-Niari River and lower Loeme River in the Republic of Congo, and the Nyanga basin and upper Ngounie River which is part of the Ogooué system in Gabon. The main part of its diet is aquatic vegetation, largely algae, but small amounts of invertebrates are eaten. It is spawns on to the substrate. This species reaches a length of SL. It is the only currently known member of its genus. The specific name honours Édou

Prosomyleus is a monospecific genus of freshwater ray-finned fish belonging to the family Serrasalmidae, the pacus, piranhas and related species. The only species in this genus is Prosomyleus rhomboidalis, which is a medium to large omnivorous fish from South America, where it is found in the Amazon River basin, as well as the north and the eastern Guiana Shield rivers. It can grow to a length of .

Alcockia is a genus in the cusk-eel family. It contains only the single species Alcockia rostrata, which is found in the Indian and western Pacific Oceans, at depths of from . This species grows to a length of SL. The generic name Alcockia honours Alfred William Alcock (1859-1933) who was the surgeon-naturalist aboard the R.I.M.S. Investigator.

REDIRECT Black-spotted parrotfish

Astatheros macracanthus, the blackthroat cichlid, is a species of cichlid freshwater fish from southern Mexico and northern Central America. It is the only recognized species in the genus Astatheros, but it was originally described in Heros, then for a long period included in Cichlasoma and until 2008 it was typically included in Amphilophus. Several other species have also been placed in Astatheros in the past, but they are now generally placed in Cribroheros. This blackthroat cichlid is omnivorous and reaches up to in standard length.