''Pareiorhina'' 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 armored catfishes native to

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

where they are only found in

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

. These

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 two individuals of the appropriate s ...

are known to occur at altitudes above 650 metres (2100 ft) in various rivers of the Grande,

Paraíba do Sul The Paraíba do Sul (), or simply termed Paraíba, is a river in southeast Brazil. It flows west to northeast from its farthest source at the source of the river Paraitinga to the sea near Campos dos Goytacazes. The river receives its name when ...

, São Francisco and Tietê River basins. This genus was first erected by Gosline in 1947 as a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus to include ''Rhinelepis rudolphi''. It was not until 2003 that a second species, ''P. carrancas'', was described. The third species, ''P. brachyrhyncha'' was described in 2005. ''Pareiorhina'' forms a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

subunit with ''

Neoplecostomus ''Neoplecostomus'' is a genus of fish in the family Loricariidae native to South America. ''Neoplecostomus'' can be distinguished from all other loricariids by a modified shield of small plates on the abdomen with posteriorly directed odontodes ...

'' within the subfamily

Neoplecostominae Neoplecostominae is a subfamily of South American catfishes of the family Loricariidae. Species of this subfamily live in high-mountain and swift-flowing river habitats. Taxonomy This subfamily is the most basal clade in Loricariidae with the ...

Species

There are currently 7 recognized species in this genus: * ''

Pareiorhina brachyrhyncha ''Pareiorhina brachyrhyncha'' is a species of armored catfish endemic to Brazil where it is known from stony piedmont tributaries of the left bank of Rio Paraíba do Sul, in the State of São Paulo, southeastern Brazil. These streams belong to t ...

'' Chamon, Aranda & Buckup, 2005 * ''

Pareiorhina carrancas ''Pareiorhina carrancas'' is a species of armored catfish endemic to Brazil. It was discovered in the Debaixo da Serra, a headwater stream with clear, cold and moderate to fast flowing water of the Rio Grande basin in the State of Minas Gerais ...

'' Bockmann & A. C. Ribeiro, 2003 * ''

Pareiorhina cepta ''Pareiorhina cepta'' is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the São Francisco River basin in the state of Minas Gerais in Brazil. It is known to occur alongside the species ''Astyana ...

'' Roxo, G. S. C. Silva, Mehanna & C. de Oliveira, 2012 * ''

Pareiorhina hyptiorhachis ''Pareiorhina hyptiorhachis'' is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the basins of the Pomba River and the Paraíba do Sul in Brazil. It is typically found in small streams with modera ...

'' G. S. C. Silva, Roxo & C. de Oliveira, 2013 * ''

Pareiorhina pelicicei ''Pareiorhina pelicicei'' is a species of cascudinho (catfish) endemic to Brazil where it is known from Córrego Tamborete, in Rio Grande basin in the State of Minas Gerais of southeastern Brazil Brazil ( pt, Brasil; ), officially the F ...

'' Azevedo-Santos & Roxo, 2015 * '' Pareiorhina rosai'' G. S. C. Silva, Roxo & Oyakawa, 2016 Silva, G.S.C., Roxo, F.F. & Oyakawa, O.T. (2016): Description of a new species of ''Pareiorhina'' (Siluriformes: Loricariidae) from the rio São Francisco basin, Brazil. ''Zootaxa, 4107 (3): 381-391.'' * '' Pareiorhina rudolphi'' ( A. Miranda-Ribeiro, 1911)

Description

Pareiorhina hyptiorhachis holotype - ZooKeys-315-065-g001-bottom

''Pareiorhina'' species all have lateral borders of the head without developed bristles, a naked abdomen, dorsal plates meeting along the mid-dorsal line between the dorsal and

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

s, no adipose fin, ventral plates covering the midventral line, and the dorsal portion of body behind dorsal fin flatenned (flat caudal peduncle with a rectangular

cross section Cross section may refer to: * Cross section (geometry) ** Cross-sectional views in architecture & engineering 3D *Cross section (geology) * Cross section (electronics) * Radar cross section, measure of detectability * Cross section (physics) **Abs ...

). In ''P. carrancas'' and ''P. rudolphi'', the teeth are simple, while in ''P. brachyrhyncha'', the teeth have a minute lateral cusp at the base of the main cusp. ''P. brachyrhyncha'' and ''P. carrancas'' are unique in lacking an adipose fin and azygous plates; in loricariids without an adipose fin, it is usually replaced by a series of azygous plates that form a ridge. However, these two species lack both the fin and the ridge. These species range from about 4.1–4.5 centimetres (1.6–1.8 in) in length.

References

{{Taxonbar, from=Q5018534 Loricariidae Fish of South America Catfish genera Taxa named by William Alonzo Gosline III Freshwater fish genera