''Trichogenes longipinnis'' (the long-finned cambeva), is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

catfish Catfish (or catfishes; order (biology), order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Catfish are common name, named for their prominent barbel (anatomy), barbels, which resemble a cat's whiskers, though not ...

(

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Siluriformes) of the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Trichomycteridae Trichomycteridae is a family of catfishes 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 of ...

. ''T. longipinnis'' is

endemic Endemism is the state of a species being found only 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 foun ...

to coastal streams in the

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

forest between

Rio de Janeiro Rio de Janeiro, or simply Rio, is the capital of the Rio de Janeiro (state), state of Rio de Janeiro. It is the List of cities in Brazil by population, second-most-populous city in Brazil (after São Paulo) and the Largest cities in the America ...

and

São Paulo São Paulo (; ; Portuguese for 'Paul the Apostle, Saint Paul') is the capital of the São Paulo (state), state of São Paulo, as well as the List of cities in Brazil by population, most populous city in Brazil, the List of largest cities in the ...

States in southeastern

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

Description

The spotted colour pattern differs consistently between stream populations, indicating genetic differentiation. This fish grows to about 14 cm (5.5 in)

standard length Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

(SL) in males and 10.6 cm (4.2 in) SL in females.

Ecology

This catfish dwells in pools beneath small waterfalls in steep hill streams flowing over rocky and sandy substrates. The density of these fish varies from three to 25 individuals/m². At densities of 18 to 25 individualsm², these fish aggregate in loose groups of up to 30 individuals. However, the largest ones tend to be solitary and territorial. Unlike most trichomycterids which are bottom-dwelling and nocturnal, ''T. longipinnis'' is

nekton Nekton or necton (from the ) is any aquatic organism that can actively and persistently propel itself through a water column (i.e. swimming) without touching the bottom. Nektons generally have powerful tails and appendages (e.g. fins, pleopods, ...

ic and active both during daytime and at night, with juvenile and small adults being more active at daytime than large adults. This catfish uses visual, tactile, and chemosensory orientation to feed on bottom-dwelling aquatic and terrestrial

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s in the water column or on the surface. Their diet includes immature aquatic insects,

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s, adult terrestrial winged insects, whole or fragmented, and

carrion Carrion (), also known as a carcass, is the decaying flesh of dead animals. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...

. These fish forage mostly by scanning the bottom, the barbels touching the substrate, but visually oriented drift feeding is also used by smaller fish. While foraging, it may bury into sand or plant debris and sift through with its gill openings and mouth. This species reproduces at the onset of rainy season. ''T. longipinnis'' is restricted to steep hill stream stretches, and is absent in streams on gently sloping terrain dominated by ''

Astyanax In Greek mythology, Astyanax (; ''Astyánax'', "lord of the city") was the son of Hector, the crown prince of Troy, and of his wife, Princess Andromache of Cilician Thebe."Astyanax". ''Oxford Classical Dictionary''. Oxford, 1949, p. 101 (''s.v. ...

'' characids. The catfish possibly developed, or retained, its characid-like role (diurnal, nektonic, and insectivorous) in separately with this more widespread tetra.

Conservation

Due to restricted distribution, specialized habitat, and differentiated populations, the vulnerable (VU B1+2bc) status in the IUCN List is proposed. However, this species is not yet listed on the IUCN Red List.

References

{{Taxonbar, from=Q3764313 Trichomycteridae Pencil catfish of Brazil Endemic fish of Brazil Fauna of the Atlantic Forest Taxa named by Heraldo Antonio Britski Taxa named by Hernán Ortega Fish described in 1983