Actinopteri (ray-finned fishes) > Osteoglossiformes
(Bony tongues) > Mormyridae
Etymology: Hyperopisus: Greek, yper = over, up + Greek, pisos, -eos, ous = a wet place. More on author: Lacepède.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; brackish; demersal; potamodromous (Ref. 51243). Tropical; 22°C - 24°C (Ref. 12468)
Africa: all Sahelo-Sudanese river basins (Ref. 81274); including Senegal River, Gambia River, Niger River, Volta River, Ouémé River, Ogun River and Chad basin (Ref. 2915). Also in Nile River basin, up to Albert and Murchison Niles (Ref. 3203).
Length at first maturity / Size / Weight / Age
Maturity: Lm 33.0  range ? - ? cm
Max length : 51.0 cm SL male/unsexed; (Ref. 2915); max. published weight: 1.0 kg (Ref. 3799)
Morphology | Morphometrics
soft rays: 52 - 71. Spots on adults only; body depth 3.9-6.2x SL; head length 4.6-6.2x SL; head in 1.6-2.3x longer than wide; base of anal fin 4-7.7x longer than dorsal fin base; the pectoral 1.1-1.7x head length; ventral 2x shorter pectoral; caudal peduncle is 1.5-3.6x its length.
Inhabits both still and flowing waters, breeds in the flood season. Feeds on mollusks (Ref. 28714). Possesses electroreceptors over the entire head and on the ventral and dorsal regions of the body, but absent from the side and the caudal peduncle where the electric organ is located (Ref. 10011). Its electric organ discharge (EOD) is steroid-sensitive (Ref. 10763; 10764). Fecundity value of 18,924 eggs has been reported for this species (Ref. 10607).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Bigorne, R., 1990. Mormyridae. p. 122-184. In C. Lévêque, D. Paugy and G.G. Teugels (eds.) Faune des poissons d'eaux saumâtres d'Afrique de l'Ouest. tome 1. Faune Trop. 28. Musée Royal de l'Afrique Centrale, Tervuren, and ORSTOM, Paris. (Ref. 2915)
IUCN Red List Status (Ref. 123251)
CITES (Ref. 123416)
Threat to humans
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 1.0000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01175 (0.00687 - 0.02010), b=2.81 (2.66 - 2.96), in cm total length, based on LWR estimates for this species & (Sub)family-body (Ref. 93245
Trophic level (Ref. 69278
): 3.6 ±0.50 se; based on food items.
Resilience (Ref. 120179
): Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Moderate to high vulnerability (47 of 100) .