The Stegophilinae are a

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 ...

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, ...

es (order Siluriformes) of the family Trichomycteridae. It includes 12 genera: '' Acanthopoma'', '' Apomatoceros'', '' Haemomaster'', '' Henonemus'', '' Homodiaetus'', '' Megalocentor'', ''

Ochmacanthus ''Ochmacanthus'' is a genus of pencil catfishes native to South America. These species are distributed in South America. ''O. alternus'' and ''O. orinoco'' originate from the Rio Negro and Orinoco River basins of Brazil and Venezuela. ''O. batra ...

'', '' Parastegophilus'', '' Pareiodon'', '' Pseudostegophilus'', '' Schultzichthys'', and '' Stegophilus''. 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 ...

group within the Stegophilinae is supported by two characteristics of the

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

, including ''Acanthopoma'', ''Henonemus'', ''Megalocentor'', ''Pareiodon'', ''Parastegophilus'', and ''Pseudostegophilus''. ''Acanthopoma'' and ''Henonemus'' have a

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 t ...

relationship. The Stegophilinae are widely distributed in the main

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 ...

n river basins, including the

Amazon Amazon most often refers to: * Amazons, a tribe of female warriors in Greek mythology * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon River, in South America * Amazon (company), an American multinational technology c ...

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 wor ...

, São Francisco, Paraná-

Paraguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...

, and those of southern

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 ...

. Eight of the genera are distributed in

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 ...

. Stegophilines are sometimes considered

candirú Candiru (''Vandellia cirrhosa''), also known as cañero, toothpick fish, or vampire fish, is a species of parasitic freshwater catfish in the family Trichomycteridae native to the Amazon Basin where it is found in the countries of Bolivia, Bra ...

, so are considered

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

s or semiparasites, because of their peculiar habit of feeding on

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...

mucus Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It is ...

, or skin of other fishes.

References

{{Taxonbar, from=Q7606706 Trichomycteridae Fish of South America Fish subfamilies Taxa named by Albert Günther