''Lithogenes'' 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 ...

of South American

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, ...

of the family

Loricariidae The Loricariidae is the largest family of catfish (order Siluriformes), with 92 genera and just over 680 species. Loricariids originate from freshwater habitats of Costa Rica, Panama, and tropical and subtropical South America. These fish are n ...

. It is the only genus within the subfamily Lithogeneinae.

Taxonomy

''Lithogenes'' is the only genus within the subfamily Lithogeneinae. This genus and subfamily, the most

basal Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''. Science * Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure * Basal (medicine), a minimal level that is nec ...

group in Loricariidae, is the

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to the rest of the family. Relative to an

undescribed species In taxonomy, an undescribed taxon is a taxon (for example, a species) that has been discovered, but not yet formally described and named. The various Nomenclature Codes specify the requirements for a new taxon to be validly described and name ...

of Lithogeneinae, ''L. valencia'' has sister group relationship to ''L. villosus''.

Species

The three recognized species in this genus are: * ''

Lithogenes valencia ''Lithogenes valencia'' is a species of Loricariidae, armored catfish found in Venezuela. This species reaches a length of . References

*Schaefer, S.A. and F. Provenzano, 2008. The Lithogeninae (Siluriformes, Loricariidae): anatomy, interre ...

Provenzano Provenzano is an Italian surname. It may refer to: *Anthony Provenzano (1917–1988), New York mobster * Bernardo Provenzano (1933–2016), member of the Sicilian Mafia *Carmen Provenzano (1942–2005), Canadian politician * Chris Provenzano, Ameri ...

Schaefer Schaefer is an alternative spelling and cognate for the German word ''schäfer'', meaning 'shepherd', which itself descends from the Old High German '' scāphare''. Variants "Shaefer", "Schäfer" (a standardized spelling in many German-speaking ...

, Baskin & Royero-Leon, 2003 * ''

Lithogenes villosus ''Lithogenes villosus'' is a species of armored catfish Armoured catfish may refer to: *Family Loricariidae: The armoured suckermouth catfish, also known as suckermouth catfish, armoured catfish or simply 'plecs' or 'plecos' *Family Callichthy ...

Eigenmann Eigenmann is a surname. Notable persons with that surname include: * Andi Eigenmann (born 1990), Filipino actress * Carl H. Eigenmann (1863–1927), German–American ichthyologist, husband of Rosa Eigenmann * Eduardo de Mesa Eigenmann, birth name ...

, 1909 * ''

Lithogenes wahari ''Lithogenes wahari'' is a species of armored catfish Armoured catfish may refer to: *Family Loricariidae: The armoured suckermouth catfish, also known as suckermouth catfish, armoured catfish or simply 'plecs' or 'plecos' *Family Callichthyidae ...

, 2008

Appearance and anatomy

As members of the family Loricariidae, all ''Lithogenes'' species have a

suckermouth In fish, a suckermouth is a ventrally-oriented (inferior) mouth adapted for grazing on algae and small organisms that grow on submerged objects. All Loricariidae possess a suckermouth as do the cypriniform algae eaters of the genus '' Gyrinocheilu ...

. However, unlike most loricariids, species of the genus ''Lithogenes'' possess armor plating only on the latter half of the body. Their eyes are small and their bodies flattened.

Distribution and habitat

''L. villosus'' originates from the

Essequibo River The Essequibo River (Spanish: ''Río Esequibo'' originally called by Alonso de Ojeda ''Río Dulce'') is the largest river in Guyana, and the largest river between the Orinoco and Amazon. Rising in the Acarai Mountains near the Brazil–Guyana b ...

drainage of the

Guiana Shield The Guiana Shield (french: Plateau des Guyanes, Bouclier guyanais; nl, Hoogland van Guyana, Guianaschild; pt, Planalto das Guianas, Escudo das Guianas; es, Escudo guayanés) is one of the three cratons of the South American Plate. It is a ...

. An undescribed species of ''Lithogenes'' is known from the

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers , with 76.3 percent of it in Venezuela and the remainder in Colombia. It is the fourth largest river in the wo ...

basin of the Guiana Shield. ''L. valencia'' has only been known from six specimens collected in the 1970s from tributaries of the Lake Valencia in northern

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in ...

; however, this area has since been polluted and this species possibly is now extinct. ''L. villosus'' lives in habitats dominated by

rapid Rapids are sections of a river where the river bed has a relatively steep gradient, causing an increase in water velocity and turbulence. Rapids are hydrological features between a ''run'' (a smoothly flowing part of a stream) and a ''cascade ...

s over

bedrock In geology, bedrock is solid rock that lies under loose material ( regolith) within the crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface material. An exposed portion of be ...

, and ''L. valencia'' likely does, as well.

References

{{Taxonbar, from1=Q11761947, from2=Q147404 Loricariidae Fish of South America Catfish genera Taxa named by Carl H. Eigenmann Freshwater fish genera