Actinopteri (ray-finned fishes) > Siluriformes
(Catfishes) > Trichomycteridae
(Pencil or parasitic catfishes) > Trichogeninae
Etymology: Trichogenes: Greek, thrix = hair + Greek, genes, genesis = birth, race (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
Freshwater; demersal; depth range - m (Ref. ), usually - m (Ref. ). Tropical; 20°C - 24°C (Ref. 13614)
South America: coastal streams between Rio de Janeiro and São Paulo States, Southeastern Brazil. Due to restricted distribution, specialized habitat, and differentiated populations, the vulnerable (VU B1+2bc) status in the IUCN List is proposed (Ref. 50917).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 14.0 cm SL male/unsexed; (Ref. 50917); 10.6 cm SL (female)
Found in streams in the Atlantic forest; backwaters with no flow to 0.44 meter per second water flow. Dwells mostly in pools beneath small waterfalls in steep hill streams flowing over rocky and sandy substrates. Density varies from 3 to 25 individuals per square meter. At densities of 18 to 25 individuals per square meter, fish aggregates in loose groups of up to 30 individuals; largest ones tend to be solitary and territorial. Nektonic, active both during daytime and at night; juveniles and small adults of up to 9 cm TL are more active at daytime, whereas larger ones are active mostly at night. Uses visual, tactile, and chemo-sensory orientation to feed on bottom-dwelling aquatic and terrestrial arthropods 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. Forages mostly by scanning the bottom, the barbels touching the substrate, but visual oriented drift feeding is also employed by individuals up to 5 cm TL. While foraging may bury into sand or plant debris and sifts through opercular openings and mouth. Reproduces at the onset of rainy season (austral summer). Mature oocytes about 0.2 cm diameter; pterigyolarvae range 1-1.5 cm TL. Spotted color pattern differs consistently between stream populations, an indication of genetic differentiation (Ref. 50917).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Burgess, W.E., 1989. An atlas of freshwater and marine catfishes. A preliminary survey of the Siluriformes. T.F.H. Publications, Inc., Neptune City, New Jersey (USA). 784 p. (Ref. 6868)
IUCN Red List Status (Ref. 124695)
Threat to humans
Fisheries: subsistence fisheries
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.7500 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00389 (0.00180 - 0.00842), b=3.12 (2.94 - 3.30), in cm total length, based on all LWR estimates for this body shape (Ref. 93245
Trophic level (Ref. 69278
): 3.4 ±0.46 se; based on food items.
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .