Teleostei (teleosts) >
Osteoglossiformes (Bony tongues) >
Mormyridae (Elephantfishes)
Etymology: Marcusenius: Becasue of J. Marcusen, author of "Zur Phauna des Schwarzen Meeres", 1867; ichthyologist.
More on author: Fowler.
Environment: milieu / climate zone / depth range / distribution range
Ecology
Freshwater; demersal. Tropical
Africa: coastal rivers draining into the Indian Ocean, ranging between tropical sections of the Limpopo River in the north and the Kosi River system in the south, including the Pongolo River which is the type river (Ref. 75962, 95448).
Size / Weight / Age
Maturity: Lm ? range ? - ? cm
Short description
Identification keys | Morphology | Morphometrics
Dorsal spines (total): 0; Dorsal soft rays (total): 20 - 23; Anal spines: 0; Anal soft rays: 26 - 28; Vertebrae: 42 - 43. Diagnosis: Marcusenius pongolensis can be distinguished from its congeners by the following characters: a more slender body, elongated, smaller body depth, 19.1-26.0% of standard length; distance from dorsal fin origin to end of caudal peduncle 37.1-39.8% of standard length; distance from anal fin origin to end of caudal peduncle 40.8-42.2% of standard length; and length of anal fin 19.5-21.9% of standard length; all shorter and non-overlapping with Marcusenius krameri, M. caudisquamatus and M. lucombesi (Ref. 95448). Total vertebrae ranges between 42-43 vs. 44 in other species; posterior total gill rakers 13-14 vs. 15 and 17 in M. caudisquamatus and M. krameri, respectively; lateral line scales 70-73; scales around caudal peduncle 16-17; dorsal fin rays 20-23; anal fin rays 26-28 (Ref. 95448). Electric organ discharge (EOD) lacking a weak head-negative pre-potential, in females and juveniles Ndur of short duration, no striking sexual dimorphism in EOD waveform present, but longer EOD duration and statistically significant increase with standard length in males (Ref. 75962).
During the day Marcusenius pongolensis is often encountered below undercut river banks, especially in dense network of tree roots; places where there is a countercurrent seem to be especially attractive; in Swaziland it has been observed high up in river systems with rapid water flow and rocky substrate in Swaziland (Ref. 75962).
Life cycle and mating behavior
Maturities | Reproduction | Spawnings | Egg(s) | Fecundities | Larvae
Kramer, B., P. Skelton, H. van der Bank and M. Wink, 2007. Allopatric differentiation in the Marcusenius macrolepidotus species complex in southern and eastern Africa: the resurrection of M. pongolensis and M. angolensis, and the description of two new species (Mormyridae, Teleostei). J. Nat. Hist. 41(9-12):647-708. (Ref. 75962)
IUCN Red List Status (Ref. 130435)
Threat to humans
Harmless
Human uses
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Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00562 (0.00251 - 0.01261), b=3.05 (2.85 - 3.25), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
Trophic level (Ref.
69278): 3.1 ±0.4 se; based on size and trophs of closest relatives
Resilience (Ref.
120179): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref.
59153): Low vulnerability (18 of 100).
