Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic; pH range: 3.0 - 6.0. Tropical
South America: main stem of Amazon River, lower Negro River basin in Brazil.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 56.0 cm TL male/unsexed; (Ref. 39524); max. published weight: 250.00 g (Ref. 52797)
Morphology | Morphometrics
soft rays: 195 - 312. Body and head of living specimens uniformly black or very dark purple-brown with no humeral spot or patch; juveniles undergo striking pigmentation change from uniformly black by day to very pale with two distinct vertical saddle-like markings at night; dorsal margin of head well rounded (very convex) in adults (Ref. 52797).
Inhabits blackwater rivers and their seasonally inundated floodplain lakes and forests (Ref. 52797). Feeds on invertebrates (Ref. 52797).
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. 125652)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82804
= 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
): 3.2 ±0.42 se; based on food items.
Fishing Vulnerability (Ref. 59153
): Moderate vulnerability (42 of 100).