Actinopterygii (ray-finned fishes) > Osteoglossiformes
(Bony tongues) > Mormyridae
Etymology: Gnathonemus: Greek, gnathos = jaw + Greek, nema = filament (Ref. 45335).
Environment / Climate / Range
Freshwater; demersal; potamodromous (Ref. 10608); depth range 27 - 45 m (Ref. 9606). Tropical, preferred ?
Length at first maturity / Size / Weight / Age
Maturity: Lm ?, range 10 - ? cm
Max length : 36.0 cm TL male/unsexed; (Ref. 52331)
Africa: Victoria Nile (Ref. 1880), Lake Kyoga (Ref. 4903), Lake Victoria basin (Ref. 34290), Middle Akagera River system (Ref. 46152), Malagarazi River (Ref. 54847, 98755), Lake Tanganyika (Ref. 45485).
In Lake Kyoga abundant among or near water lilies (Ref. 49805) and in Lake Victoria it occurs in shallow, inshore waters over sandy and rocky shores (Ref. 4903, 97924), seasonally over muddy bottoms adjacent to papyrus swamps or deep water near rocky islands (Ref. 9606, 97924). Feeds on bottom and in marginal vegetation; insectivorous (chironomid larvae, Povilla, Odonata larvae), but arthropods, oligochaetes and fish eggs are also eaten (Ref. 12526). Uses sensitive pointed addition to chin for testing holes in mud, papyrus roots and between stones to locate underwater insects (Ref. 36900). Rotates body to almost vertical position, searches substrate and grabs prey into mouth; produces weak electric organ discharge for navigation and to warn off other organisms (Ref. 97924). Oviparous (Ref. 205). Breeds twice a year during the rainy seasons, and migrates up rivers to spawn (Ref. 10608).
Gosse, J.-P., 1984. Mormyridae. p. 63-122. In J. Daget, J.-P. Gosse and D.F.E. Thys van den Audenaerde (eds.) Check-list of the freshwater fishes of Africa (CLOFFA). ORSTOM, Paris and MRAC, Tervuren. Vol. 1. (Ref. 3203)
IUCN Red List Status (Ref. 96402)
CITES (Ref. 94142)
Threat to humans
Fisheries: of no interest
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5625 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01318 (0.00609 - 0.02852), b=2.84 (2.66 - 3.02), based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.2 ±0.3 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
): Medium, minimum population doubling time 1.4 - 4.4 years (Fec = 502).
Vulnerability (Ref. 59153
): Low to moderate vulnerability (29 of 100) .