Actinopterygii (ray-finned fishes) > Polypteriformes
(Bichirs) > Polypteridae
Etymology: Polypterus: Greek, poly = a lot of + Greek, pteron = wing, fin (Ref. 45335).
Environment / Climate / Range
Freshwater; demersal; pH range: 6.0 - 8.0; dH range: 5 - 19; potamodromous (Ref. 51243). Tropical; 25°C - 28°C (Ref. 2060)
Length at first maturity / Size / Weight / Age
Maturity: Lm ?, range 15 - 23 cm
Max length : 70.0 cm SL male/unsexed; (Ref. 3188); max. published weight: 207.00 g (Ref. 3013)
(total): 8 - 11;
Vertebrae: 53 - 59. Cylindrical body (Ref. 2835, Ref. 3036, Ref. 30488). Body depth 7.6 to 10.6 times in standard length; head length 5.75 to 7 times in standard length (Ref. 2835, Ref. 45628). Upper jaw slightly prominent or sometimes jaws are of equal length (Ref. 1989, Ref. 2756, Ref. 2835). Dorsal fin with 8-11 finlets, anterior separated from each other when folded (Ref. 42908). Number of branched dorsal and caudal rays: 15-19 (Ref. 367, Ref. 2835, Ref. 3069). Pectoral fin not reaching the first dorsal spine (Ref. 2756, Ref. 28714, Ref. 13851, Ref. 30488). Ganoid scales (Ref. 42904): 53-61 lateral line scales, 32-40 scales around body, 14-21 predorsal scales (Ref. 2835, Ref. 42908, Ref. 43745). Dorsal surface uniform olive-colored and ventral side white, without blotches or marbling (Ref. 367, Ref. 3036, Ref. 30488). Fins are gray-colored (Ref. 367). Young specimens have three dark longitudinal bands on the flanks, but these markings disappear at an early age (Ref. 2835, Ref. 13851, Ref. 31439).
Africa: Nile basin and West Africa, including Senegal, Gambia, Niger, Volta and Lake Chad basins (Ref. 2835) and Congo River basin (Ref. 3188). Previously, 2 subspecies were recognized: Polypterus senegalus meridionalis and Polypterus senegalus senegalus. Only the former occurs in the Congo River basin, from the upper Lualaba (Ref. 45434) downstream to Yangambi (Ref. 4910), in Democratic Republic of the Congo.
This species inhabits marginal swamps and freshwater lagoons (Ref. 3066) and it appears to favor sheltered inshore habitats (Ref. 3034); it inhabits the muddy regions at the sides of rivers and swampy waters, where it lies quiet or glides about with snake-like movements (Ref. 49805). During the hottest hours of the day, it comes to the surface just on the outer edge of the vegetation, and it goes back to the bottom when disturbed (Ref. 45962). It feeds on insects, crustaceans, mollusks, frogs and fishes (Ref. 4903, Ref. 28714). Polypterus senegalus senegalus is mainly insectivorous (Ref. 367). Longevity of Polypterus senegalus in captivity can be 34 years and more (Ref. 48954).
Larval fish 1.1-3.8 cm SL were found in papyrus root mat and juveniles up to 10 cm SL retaining external gills were found in fringing water hyacinth. Feeds mainly on fishes (Ref. 9695), insects, crustaceans, mollusks, frogs as well as on plant fragments and seeds.
In Polypterus senegalus courtship starts with a series of leaps from the surface by usually only one of the pair at a time, followed by a slow descent through the water. After a while the male stays very close to the female and at times the female will remain motionless in the water and the male will come up to her from behind and nudge her with sidewise movements of his head. The enlarged and swollen anal fin of the male is folded in a cup-like fashion and is used to brush the female (Ref. 42791). No nest is constructed, but the eggs are laid a few at a time throughout the thick vegetation (Ref. 42791). The larvae, which move about with the male parent in a dense school, are provided with accessory gills and appear very salamander-like (Ref. 42791).
Gosse, J.-P., 1990. Polypteridae. p. 79-87. In C. Lévêque, D. Paugy and G.G. Teugels (eds.) Faune des poissons d'eaux douces et saumâtres d'Afrique de l'Ouest. Tome 1. Coll. Faune Trop. n° XXVIII. Musée Royal de l'Afrique Centrale, Tervuren and Éditions de l'ORSTOM, Paris. 384 p. (Ref. 2835)
IUCN Red List Status (Ref. 96402)
CITES (Ref. 94142)
Threat to humans
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5002 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00537 (0.00310 - 0.00931), b=3.00 (2.84 - 3.16), based on LWR estimates for species & (Sub)Family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.5 ±0.2 se; Based on diet studies.
Resilience (Ref. 69278
): Very Low, minimum population doubling time more than 14 years (tmax=34; Fec < 1,000).
Vulnerability (Ref. 59153
): Moderate to high vulnerability (50 of 100) .