Trichogenes longipinnis

Taxobox
name = "Trichogenes longipinnis"
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Siluriformes
familia = Trichomycteridae
subfamilia = Trichogeninae
subfamilia_authority = Isbrücker, 1986
genus = "Trichogenes"
genus_authority = Britski & Ortega, 1983
species = "T. longipinnis"
binomial = "Trichogenes longipinnis"
binomial_authority = Britski & Ortega, 1983

"Trichogenes longipinnis" is a species of catfish (order Siluriformes) of the family Trichomycteridae, and the only species of the subfamily Trichogeninae. [cite journal|url=http://silurus.acnatsci.org/ACSI/library/biblios/2007_Ferraris_Catfish_Checklist.pdf|title=Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types|first=Carl J., Jr.|last=Ferraris|journal=Zootaxa|volume=1418|pages=1–628|year=2007|format=PDF]

Distribution

"T. longipinnis" is endemic to coastal streams in the Atlantic forest between Rio de Janeiro and São Paulo States in southeastern Brazil.cite journal|title=Natural history of "Trichogenes longipinnis", a threatened trichomycterid catfish endemic to Atlantic forest streams in southeast Brazil|first=Ivan|last=Sazima|journal=Ichthyol. Explor. Freshwaters|volume=15|issue=1|pages=49–60|date=March 2004]

Description

The spotted colour pattern differs consistently between stream populations, indicating genetic differentiation. This fish grows to about 14 centimetres (5.5 in) SL in males and 10.6 cm (4.2 in) SL in females.FishBase species|genus=Trichogenes|species=longipinnis|year=2007|month=July]

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 3 to 25 individuals per square metre. At densities of 18 to 25 individuals per square meter, 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 nektonic 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 chemo-sensory orientation to feed on bottom-dwelling aquatic and terrestrial insects in the water column or on the surface. Diet includes immature aquatic insects, crustaceans, adult terrestrial winged insects whole or fragmented, as well as carrion. These fish forage mostly by scanning the bottom, the barbels touching the substrate, but visual oriented drift feeding is also employed by smaller individuals. 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" 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