Trichomycterus
Encyclopedia
Trichomycterus is a genus of catfish
es, the largest genus in the family Trichomycteridae
with over 100 species currently described.
. Although known to contain many species, Trichomycterus is poorly known with many of the known species based on brief descriptions. Many species have been described recently and many more are waiting to be described.
Some authors have tentatively defined putative monophyletic
assemblages within the genus Trichomycterus based on the possession of unique morphological features. The T. brasiliensis species-complex includes T. brasiliensis, T. iheringi, T. maracaya, T. mimonha, T. potschi, T. vermiculatus, and several undescribed species apparently endemic to the main river basins draining the Brazil
ian Shield. However, an assemblage of species from south and southeastern Brazil is also supported that includes T. guaraquessaba, T. iheringi, T. nigricans, T. davisi, T. stawiarski, T. castroi, T. triguttatum, T. immaculatus, T. itatiayae, T. mirissumba, T. zonatus, T. naipi, T. taboba, T. papilliferus, T. mboycy, and T. plumbeus. T. aguarague, T. alterus, T. boylei, T. ramosus, and T. belensis also form a diagnosable species assemblage.
and Central America
from Costa Rica
in the north to Patagonia
in the south, and from lowland Atlantic rainforest in the east to Andean
streams in the west. A number of species of Trichomycterus are known from various mid- to high-elevation localities in western Argentina
; in these upland regions the species of Trichomycterus are among the few, or sometimes only, fishes occupying water bodies at middle to higher elevations. About 60 nominal species are endemic to the river basins draining the Andes and hills of the Guianan Shield, and about 30 species are endemic to river basins draining the Brazil
ian Shield.
Despite the broad distribution of the genus, most species have limited distributions, and usually are restricted to only one river. Wide-ranging species are most likely complexes of species that are difficult to differentiate, such as the T. brasiliensis species-complex. Trichomycterus gorgona, from a small stream on Gorgona Island
located west of the Pacific coast of Colombia
, is the first known trichomycterid to be endemic to an offshore island.
Six hypogean species are in the genus Trichomycterus: Trichomycterus chaberti, T. itacarambiensis, T. santanderensis, T. spelaeus, and T. uisae.
. Species differ from one another primarily in body proportions, fin ray counts, and colouration.
Catfish
Catfishes 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 heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...
es, the largest genus in the family Trichomycteridae
Trichomycteridae
Trichomycteridae is a family of catfishes commonly known as the pencil or parasitic catfishes. This family includes the infamous candiru fish, feared by some people for its alleged habit of entering into the urethra of humans....
with over 100 species currently described.
Taxonomy
This genus is defined by the lack of specializations found in other trichomycterids and is certainly polyphyleticPolyphyly
A polyphyletic group is one whose members' last common ancestor is not a member of the group.For example, the group consisting of warm-blooded animals is polyphyletic, because it contains both mammals and birds, but the most recent common ancestor of mammals and birds was cold-blooded...
. Although known to contain many species, Trichomycterus is poorly known with many of the known species based on brief descriptions. Many species have been described recently and many more are waiting to be described.
Some authors have tentatively defined putative monophyletic
Monophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
assemblages within the genus Trichomycterus based on the possession of unique morphological features. The T. brasiliensis species-complex includes T. brasiliensis, T. iheringi, T. maracaya, T. mimonha, T. potschi, T. vermiculatus, and several undescribed species apparently endemic to the main river basins draining the Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
ian Shield. However, an assemblage of species from south and southeastern Brazil is also supported that includes T. guaraquessaba, T. iheringi, T. nigricans, T. davisi, T. stawiarski, T. castroi, T. triguttatum, T. immaculatus, T. itatiayae, T. mirissumba, T. zonatus, T. naipi, T. taboba, T. papilliferus, T. mboycy, and T. plumbeus. T. aguarague, T. alterus, T. boylei, T. ramosus, and T. belensis also form a diagnosable species assemblage.
Distribution and habitat
Species of Trichomycterus inhabit a diversity of habitats throughout SouthSouth America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
and Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
from Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
in the north to Patagonia
Patagonia
Patagonia is a region located in Argentina and Chile, integrating the southernmost section of the Andes mountains to the southwest towards the Pacific ocean and from the east of the cordillera to the valleys it follows south through Colorado River towards Carmen de Patagones in the Atlantic Ocean...
in the south, and from lowland Atlantic rainforest in the east to Andean
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
streams in the west. A number of species of Trichomycterus are known from various mid- to high-elevation localities in western Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
; in these upland regions the species of Trichomycterus are among the few, or sometimes only, fishes occupying water bodies at middle to higher elevations. About 60 nominal species are endemic to the river basins draining the Andes and hills of the Guianan Shield, and about 30 species are endemic to river basins draining the Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
ian Shield.
Despite the broad distribution of the genus, most species have limited distributions, and usually are restricted to only one river. Wide-ranging species are most likely complexes of species that are difficult to differentiate, such as the T. brasiliensis species-complex. Trichomycterus gorgona, from a small stream on Gorgona Island
Gorgona, Colombia
Gorgona is a Colombian island in the Pacific Ocean situated about 50 km off the Colombian Pacific coast and part of the municipality of Guapi in the Department of Cauca. The island is about 9 km long and 2.5 km wide, with a maximum height of 338 m ; with an area of 10 square miles...
located west of the Pacific coast of Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, is the first known trichomycterid to be endemic to an offshore island.
Six hypogean species are in the genus Trichomycterus: Trichomycterus chaberti, T. itacarambiensis, T. santanderensis, T. spelaeus, and T. uisae.
Description
These fish are generally small, usually about 50–150 millimetres (2–6 in) SLFish measurement
Fish measurement refers to the measuring of the length of individual fish and of various parts of their anatomy. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.-Overall length:...
. Species differ from one another primarily in body proportions, fin ray counts, and colouration.
Species
Species list according to Ferraris, 2007; newer species with references.
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Trichomycterus guaraquessaba Trichomycterus guaraquessaba is a species of catfish belonging to the family Trichomycteridae. It is presently only known from Rio Bracinho, a small isolated river in Paraná state, Brazil.This is an elongate catfish up to around 90 mm standard length... Trichomycterus iheringi Trichomycterus iheringi is a species of catfish belonging to the family Trichomycteridae. It is restricted to a small area of coastal Brazil in São Paulo and Paraná states, centred on Santos.This is an elongate catfish up to around 140 mm standard length... Trichomycterus laucaensis Trichomycterus laucaensis is a species of fish in the Trichomycteridae family. It is endemic to Chile.-Source:* World Conservation Monitoring Centre 1996. . Downloaded on 5 August 2007.... |
Trichomycterus rivulatus Trichomycterus rivulatus is a species of fish in the Trichomycteridae family. It is endemic to the Lake Titicaca basin.-Source:* World Conservation Monitoring Centre 1996. . Downloaded on 5 August 2007.... Trichomycterus trefauti Trichomycterus trefauti is a species of catfish. It is presently only known from the upper basin of the São Francisco River in Minas Gerais state, Brazil.... |