The Trichomycterinae 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 six

genera 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 nomenclat ...

, '' Bullockia'', '' Hatcheria'', '' Rhizosomichthys'', and '' Eremophilus'', all

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 ...

, '' Silvinichthys'' with two

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 ...

, and '' Trichomycterus'', with over 100 species. The former five genera are diagnosed by putatively

apomorphic In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

characters, whereas ''Trichomycterus'' is defined by the lack of those specializations and is likely not

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 ...

. This subfamily has historically served as much of a wastebasket for trichomycterids that lack the specializations of the other subfamilies. Species of Trichomycterinae dwell in headwaters and small, cold clear water streams running over stony beds. Due to the patchy distribution of their habitats, trichomycterines generally have restricted geographic distributions, thus display a high level of

endemism Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

References

Trichomycteridae Fish of South America Ray-finned fish subfamilies {{Trichomycteridae-stub