The Kneriidae are a small family of freshwater gonorhynchiform fishes native to

sub-Saharan Africa Sub-Saharan Africa is the area and regions of the continent of Africa that lie south of the Sahara. These include Central Africa, East Africa, Southern Africa, and West Africa. Geopolitically, in addition to the list of sovereign states and ...

. The species in this family typically live in fast-flowing streams, often in highlands, and are small fish, no more than in length. The second subfamily Phractolaeminae contains only a single species, which typically inhabits stagnant or slow-moving waters and reaches up to in length. All Kneriidae have an elongated body shape. Some species are

sexually dimorphic Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

, with the male possessing a rosette on the

gill cover The operculum is a series of bones found in bony fish and Chimaera, chimaeras that serves as a facial support structure and a protective covering for the gills; it is also used for respiration and feeding. Anatomy The opercular series contain ...

s that is absent in the females. Other species are

neotenic Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny in modern humans is more signif ...

, retaining larval features into adulthood.

Classification

There are about 31 extant (living) species in four genera. Phractolaemidae is now regarded as a full family.

Genera

* ''

Cromeria ''Cromeria'' is a small genus of fish in the family Kneriidae found in fresh waters in the Sudan, Mali, and Guinea in the Nile and Niger Rivers of Africa. These reach a length of up to 4.4 cm. The currently recognized species are:Moritz, T., ...

'' Boulenger, 1901 * ''

Grasseichthys ''Grasseichthys gabonensis'' is an extremely small (around 2 cm) fish native to the Ivindo and Central Congo basins of Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 mi ...

Géry Géry () is a commune in the Meuse department in Grand Est in north-eastern France. See also *Communes of the Meuse department The following is a list of the 499 Communes of France, communes of the Meuse (department), Meuse Departments of ...

, 1964 * ''

Kneria ''Kneria'' is a genus of small fish in the family Kneriidae. All the species in this genus are restricted to Africa. Named in honor of Austrian ichthyologist Rudolf Kner (1810-1869) Species The following species are included in this genus: ...

Steindachner Franz Steindachner (11 November 1834 in Vienna – 10 December 1919 in Vienna) was an Austrian zoologist, ichthyologist, and herpetologist. He published over 200 papers on fishes and over 50 papers on reptiles and amphibians. Steindachner descri ...

, 1866 * ''

Parakneria ''Parakneria'' is a genus of fish in the family Kneriidae, with 15 species, all of which are restricted to Africa. Species There are 15 species: * ''Parakneria abbreviata'' (Jacques Pellegrin, Pellegrin, 1931) * ''Parakneria alytogrammus'' Pa ...

Poll Poll, polled, or polling may refer to: Forms of voting and counting * Poll, a formal election ** Election verification exit poll, a survey taken to verify election counts ** Polling, voting to make decisions or determine opinions ** Polling pla ...

, 1965 In addition, the family includes the genus '' Mahengichthys'' Davis, Arratia & Kaiser, 2013, which only is known from

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

remains and is closer to Kneriinae than

Phractolaemidae The hingemouth (''Phractolaemus ansorgii'') is a small freshwater fish that is found only in west central Africa, the sole member of the family Phractolaemidae of the family Kneriidae. The mouth can extend like a small trunk, thus the name, and ...

References

{{Authority control Taxa named by Albert Günther * Otocephala families de:Ohrenfische