Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Gymnotiformes
(Knifefishes) > Sternopygidae
Etymology: Sternopygus: Greek, sternon = sternon, + Greek, pyge = tail (Ref. 45335); branco: Specific epithet from the Portuguese word meaning white, referring to the characteristic pale color of freshly netted live specimens; noun in apposition.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical
South America: Amazon River, Brazil.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 49.2 cm TL male/unsexed; (Ref. 52797)
Morphology | Morphometrics
Occurs in the main channels of major rivers or side branches; not known to occur in seasonally inundated floodplain forests or in forest steams of the Amazon's terra firme. In the Tefé region, this species is caught with beach seines and trawl nets at depth up to 10 meters in areas with weak currents, such as in large eddies, sheltered bays or "paranás" (side-branches of the main river channels that wind their way through the whitewater "várzea" floodplain); occurs syntopically with Sternopygus macrurus in whitewater habitats, but never with Sternopygus atrabes. This species does not occur where currents near the substrate exceeded 0.1 m/sec. At daytime it is usually encountered near submerged structures such as fallen trees and driftwood, and at night it moves into shallower water and away from structures. Specimens are collected on both sand and mud bottoms. It does not live in groups as indicated by electrode surveys and its sporadic occurrence in nets. Sexually mature males were never encountered, but gravid females were found along the edge of whitewater floodplain areas and in paraná channels during the rising water months of January and February. Feeds mainly on autochthonous insect larvae which it encounters on the substrate; the presence of small pieces of wood in many of the stomachs indicate that it forages among organic detritus on the river bed rather than within rafts of floating meadows or marginal macrophytes (Ref. 55493).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Crampton, W.G.R., K.G. Hulen and J.S. Albert, 2004. Redescription of Sternopygus obtusirostris (Gymnotiformes: Sternopygidae) from the Amazon basin, with description of osteology, ecology and electric organ discharges. Ichthyol. Explor. Freshwat. 15(2):121-134. (Ref. 52797)
IUCN Red List Status (Ref. 115185)
CITES (Ref. 115941)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5020 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01000 (0.00244 - 0.04107), b=3.04 (2.81 - 3.27), in cm Total Length, based on all LWR estimates for this body shape (Ref. 93245
Trophic Level (Ref. 69278
): 2.6 ±0.27 se; Based on food items.
Resilience (Ref. 69278
Vulnerability (Ref. 59153
): Low to moderate vulnerability (25 of 100) .