Actinopterygii (ray-finned fishes) > Polypteriformes
(Bichirs) > Polypteridae
Etymology: Erpetoichthys: Greek, erpeton = creeping thing + Greek, ichthys = fish (Ref. 45335); calabaricus: Named after the locality where the fish was taken: Old Calabar (Ref. 42916).
Environment / Climate / Range
Freshwater; brackish; demersal; pH range: 6.0 - 8.0; dH range: 5 - 19; depth range 0 - ? m (Ref. 557). Tropical; 22°C - 28°C (Ref. 1672)
Length at first maturity / Size / Weight / Age
Maturity: Lm 31.4  range ? - ? cm
Max length : 37.0 cm SL male/unsexed; (Ref. 81628)
Morphology | Morphometrics
(total): 7 - 13;
soft rays: 9 - 14;
Vertebrae: 110 - 113. Diagnosis: The dorsal fin is composed of a series of well-separated spines each supporting one or several articulated rays and a membrane (Ref. 42791). Erpetoichthys calabaricus is distinguished from all Polypterus species by its very elongated, anguilliform body and the absence of ventral fin and subopercle (Ref. 2835, 42768, 81263).
Africa: coastal species, inhabiting river estuaries from Ouémé River in Benin to Sanaga River in Cameroon (Ref. 53784, 81628). Also reported from the Chiloango River (Ref. 1878, 2835, 3188, 42870, 43033, 81263), but this record needs confirmation and needs to be supported by additional material evidence (Ref. 53784, 81628).
Found in slow flowing rivers and standing waters (Ref. 557). Apparently restricted to reedy habitats (Ref. 42768). It moves snake-wise over the bottom, but it can also side-wind quite rapidly through the water (Ref. 42873). Feeds at night on worms, crustaceans and insects (Ref. 7020). Able to breathe air and thus can tolerate low oxygen concentrations. Larvae have external gills and resemble salamander larvae (Ref. 557). The maximum size of 90 cm TL (Ref. 3188) is probably erroneous; the largest size in collections is 37 cm (Ref. 78138).
Parallel swimming courtship; female deposits few eggs between anal fins of male, where they are fertilized and then scattered in vegetation where they immediately stick to substrate. This procedure is repeated many times. Eggs are 2.1-2.6 mm in diameter. Larvae hatch after 70 hours but remain attached to vegetation; 22 days after hatching the yolk sac is absorbed and larvae start feeding.
Britz, R., 2007. Polypteridae. p. 168-173. In M.L.J. Stiassny, G.G. Teugels and C.D. Hopkins (eds.) The fresh and brackish water fishes of Lower Guinea, West-Central Africa. Volume I. Collection Faune et Flore tropicales 42. Institut de Recherche pour le Développement, Paris, France, Muséum National d’Histoire Naturelle, Paris, France, and Musée Royal de l’Afrique Centrale, Tervuren, Belgium. 800 pp. (Ref. 81628)
IUCN Red List Status (Ref. 96402)
CITES (Ref. 94142)
Threat to humans
Fisheries: of no interest; aquarium: commercial
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 1.0001 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00132 (0.00060 - 0.00289), b=2.99 (2.79 - 3.19), based on LWR estimates for this Family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.3 ±0.40 se; Based on food items.
Resilience (Ref. 69278
): Low, minimum population doubling time 4.5 - 14 years (tmax=20; Fec < 1,000).
Vulnerability (Ref. 59153
): Moderate vulnerability (35 of 100) .