Trichomycteridae is a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

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 commonly known as pencil catfishes or parasitic catfishes. This family includes the candiru fish (''Vandellia cirrhosa''), feared by some people for its alleged habit of entering into the

urethra The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra con ...

of humans. They are one of the few parasitic

chordates A chordate () is an animal of the phylum Chordata (). All chordates possess, at some point during their larval or adult stages, five synapomorphies, or primary physical characteristics, that distinguish them from all the other taxa. These five ...

. Another species is the life monsefuano (''Trichomycterus punctulatus'') which was important to the

Moche culture The Moche civilization (; alternatively, the Mochica culture or the Early, Pre- or Proto-Chimú) flourished in northern Peru with its capital near present-day Moche, Trujillo, Peru from about 100 to 700 AD during the Regional Development Epoch. ...

and still an important part of

Peruvian cuisine Peruvian cuisine reflects local practices and ingredients including influences mainly from the indigenous population, including the Inca, and cuisines brought by immigrants from Europe (Spanish cuisine, Italian cuisine); Asia (Japanese cuisine an ...

.Fondazioneslowfood
Life monsefuano.
Retrieved 28 April 2017. This family is prohibited from being imported into various parts of the United States.

Taxonomy

The Trichomycteridae comprise about 42

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 ...

and 286

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 ...

described. It is the second-most diverse family of the superfamily

Loricarioidea Loricarioidea is a superfamily of catfishes ( order Siluriformes). It contains the six families Trichomycteridae, Nematogenyiidae, Callichthyidae, Scoloplacidae, Astroblepidae, and Loricariidae. Some schemes also include Amphiliidae. This superf ...

. Numerous species still remain undescribed. The

monophyly 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 grou ...

of Trichomycteridae is well-supported. The family is divided into eight subfamilies. The only subfamily that is 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 ...

is the largest one, Trichomycterinae. A large

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

within Trichomycteridae is also suggested that includes the subfamilies Tridentinae, Stegophilinae, Vandelliinae, Sarcoglanidinae and Glanapteryginae (the so-called TSVSG clade); this large clade in turn forms a larger monophyletic group with the two genera ''

Ituglanis ''Ituglanis'' is a genus of small freshwater fish in the family Trichomycteridae native to South America. Their greatest diversity seems to occur in the Amazon River basin.Datovo, A. & Landim, M.I. (2005)''Ituglanis macunaima'', a new catfish fr ...

'' and '' Scleronema''. The latter two genera are not classified in any of the subfamilies. The basal subfamilies

Copionodontinae The Copionodontinae are a subfamily of catfishes (order Siluriformes) of the family Trichomycteridae Trichomycteridae is a family of catfishes commonly known as pencil catfishes or parasitic catfishes. This family includes the candiru fish ...

and

Trichogeninae ''Trichogenes'' is a genus of pencil catfishes. It is currently the only genus within the subfamily ''Trichogeninae''. A third species was described in 2020 from archival material of unknown origin. The wild distribution of the new species, ' ...

are

sister A sister is a woman or a girl who shares one or more parents with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to refer to ...

groups to each other, and together they form a clade that is sister to the rest of the Trichomycteridae. Subfamilies and genera include:

Distribution

Trichomycteridae has the greatest distribution of any catfish family. It is widely distributed throughout the

Neotropics The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropics, tropical Ecoregion#Terrestrial, terrestrial ecoregions of the Americas and the entire South American temperat ...

. These fish originate from freshwater in

Costa Rica Costa Rica (, ; ; literally "Rich Coast"), officially the Republic of Costa Rica ( es, República de Costa Rica), is a country in the Central American region of North America, bordered by Nicaragua to the north, the Caribbean Sea to the no ...

Panama Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Cos ...

, and throughout

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 ...

. The family extends from Panama southward to

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

and

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

Description

The bodies of these fish are normally naked and elongated. The chin barbels are usually absent, nasal

barbel Barbel may refer to: *Barbel (anatomy), a whisker-like organ near the mouth found in some fish (notably catfish, loaches and cyprinids) and turtles *Barbel (fish), a common name for certain species of fish **''Barbus barbus'', a species of cyprinid ...

s are usually present, and there are usually two pairs of maxillary barbels. Most of these fish have no

adipose 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 s ...

, and some also lack

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

s. Many trichomycterids are small enough to be considered "miniatiurized" (do not exceed SL). Miniaturization occurs in many of the trichomycterid subfamilies, including Trichomycterinae, Glanapteryginae, Vandelliinae (in ''Paravandellia''), Tridentinae, and Sarcoglanidinae. Miniaturization has probably occurred four times in trichomycterid evolution, as the Glanapteryginae and Sarcoglanidinae are closely related and may have a single miniaturized ancestor.

Ecology

Though the family is commonly known as "parasitic catfishes", Trichomycteridae may actually include the widest range of trophic adaptations within any single catfish family. Only the two subfamilies Vandelliinae and Stegophilinae and Tridensimilis of Tridentinae are considered to be

parasitic 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 c ...

fishes, including the infamous '' candirú'' or vampire catfish, feared by some people for its habit of entering into the

of humans. Apart from the free-living, generalized predators of small invertebrates, trophic modes represented by trichomycterids include the

hematophagy Hematophagy (sometimes spelled haematophagy or hematophagia) is the practice by certain animals of feeding on blood (from the Greek words αἷμα ' "blood" and φαγεῖν ' "to eat"). Since blood is a fluid tissue rich in nutritious pro ...

(feeding on blood) in Vandelliinae, the

lepidophagy Lepidophagy is a specialised feeding behaviour in fish that involves eating the scales of other fish. Lepidophagy is widespread, having evolved independently in at least five freshwater families and seven marine families. A related feeding behavi ...

(scales) and

mucophagy Mucophagy (literally "mucus feeding") is defined as the act of feeding on mucus of fishes or invertebrates. Also, it may refer to consumption of mucus or dried mucus in primates. There are mucophagous parasites, such as some types of sea lice tha ...

(mucus) in some Stegophilinae and

necrophagy Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding be ...

(carrion) in others, and partial algivory (algae) in Copiondontinae. Trichomycteridae include species that are active swimmers (Copionodontinae and Trichogeninae), torrent dwellers (Trichomycterinae), litter leaf dwellers (''Ituglanis''), and sand dwellers (Glanapteryginae and Sarcoglanidinae). Species may be restricted to elevations above 4000 m (13000 ft) in the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

, Andean lakes, off-shore coastal islands, lowland species known only from large rapids, leaflitter puddles, and the bottom of torrential rivers. Trichomycterids are one of the most successful groups to occupy cave habitats; it contains 12

hypogean Hypogeal, hypogean, hypogeic and hypogeous (; ) are biological terms describing an organism's activity below the soil surface. In botany, a seed is described as showing hypogeal germination when the cotyledons of the germinating seed remain n ...

species. Such species include ''Ituglanis bambui'', ''I. epikarsticus'', ''I. passensis'', ''I. ramiroi'', and ''Silvinichthys bortayro''. Six of the hypogean species are of the genus ''

Trichomycterus ''Trichomycterus'' is a genus of fish in the family Trichomycteridae, the largest genus of its family with over 170 species currently described. This genus is native to freshwater habitats in Central and South America. These fish are generally sm ...

'': ''Trichomycterus chaberti'', ''T. itacarambiensis'', ''T. santanderensis'', ''T. spelaeus'', and ''T. uisae''.

References

{{Taxonbar, from=Q134551 Catfish families Fish of South America Taxa named by Pieter Bleeker