''Lithogenes'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 not ...

. It is the only genus within the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Lithogeneinae.

Taxonomy

''Lithogenes'' is the only genus within the subfamily Lithogeneinae. This genus and subfamily, the most basal group in Loricariidae, is the sister group 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 named. U ...

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 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 ...

'' Provenzano,

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 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 ...

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 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 ...

& Provenzano, 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 ''Gyrinocheilus' ...

. 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 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 th ...

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

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

, 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