Teleostei (teleosts) > Osteoglossiformes
(Bony tongues) > Mormyridae
Etymology: Marcusenius: Becasue of J. Marcusen, author of "Zur Phauna des Schwarzen Meeres", 1867; ichthyologist.
More on author: Linnaeus.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; demersal; potamodromous (Ref. 51243). Tropical
Africa: Nile (delta to Bahr-el-Jebel), Niger (Lower Niger and Benoué) and Chad basins (Ref. 3203, 81274).Also reported from the Albert Nile and Aswa River (White Nile basin) in Uganda and from the upper Congo (Ref. 4903), but the latter seems outside the species distribution area and is questionable.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 33.0 cm SL male/unsexed; (Ref. 2915); max. published weight: 458.00 g (Ref. 2915)
Morphology | Morphometrics
soft rays: 30 - 37. Diagnosis: teeth small and conical (Ref. 4903, 81274), arranged in a single series confined to the middle of each jaw, 5-6 in both jaws (Ref. 4903). 16(-18) scales around caudal peduncle (Ref. 4903, 81274). Body depth 3.0-4.7 times in standard length; anal-fin base 0.7-0.9 times in dorsal-fin base (Ref. 81274). Head length 4-5.5 times in SL; upper head profile gently curved; snout 1/3-1/4 length of head; eye 1/2-2/3 length of snout; mouth small, a globular, fleshy swelling on the chin (Ref. 4903). Dorsal fin beginning slightly behind level of anal fin-origin (Ref. 2915, 81274), above the the 6th-9th anal fin ray (Ref. 4903) and comprising 25-31 rays (Ref. 2915, 4903, 81274). 70-92 lateral-line scales (Ref. 4903, 81274). Caudal-peduncle 2.0-3.4 times longer than deep (Ref. 2915, 4903, 81274). Caudal fin partly covered with small scales, its lobes pointed (Ref. 4903).
Coloration: silvery-grey, sometimes dark grey to blackish (Ref. 81274) or dark bluish-green dorsally (Ref. 4903).
Inhabits lakes, lagoons, reservoirs and (irrigation) canals; a bottom feeding insectivore; breeds during the flood season and enters the floodplain for this purpose (Ref. 28714). Shows three 'preferred' modes of intervals between electric organ discharges (inter-EOD) when at rest: 10-35 ms, 50-120 ms and 200-350 ms (Ref. 10833).
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. 126983)
Threat to humans
Fisheries: minor commercial
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82804
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01175 (0.00668 - 0.02065), b=2.85 (2.70 - 3.00), in cm total length, based on LWR estimates for this species & Genus-body shape (Ref. 93245
Trophic level (Ref. 69278
): 3.0 ±0.37 se; based on food items.
Resilience (Ref. 120179
): Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref. 59153
): Low to moderate vulnerability (30 of 100).