The West African bichir or retropinnis bichir (''Polypterus retropinnis''), is a freshwater fish in the family

Polypteridae Bichirs and the reedfish comprise Polypteridae , a family of archaic ray-finned fishes and the only family in the order Polypteriformes .Helfman GS, Collette BB, Facey DE, Bowen BW. 2009. The Diversity of Fishes. West Sussex, UK: Blackwell Pub ...

, is found in the central

Congo River basin The Congo River, formerly also known as the Zaire River, is the second-longest river in Africa, shorter only than the Nile, as well as the third-largest river in the world list of rivers by discharge, by discharge volume, following the Amazon Ri ...

and

Ogooué River The Ogooué (or Ogowe), also known as the Nazareth River, some long, is the principal river of Gabon in west-central Africa and the fourth largest river in Africa by volume of discharge, trailing only the Congo, Kasai and Niger. Its watershed ...

in Africa. It is a long, slender fish that grows to a maximum length of about .

Description

Bichir Bichirs and the reedfish comprise Polypteridae , a family (biology), family of archaic Actinopterygii, ray-finned fishes and the only family in the order (biology), order Polypteriformes .Helfman GS, Collette BB, Facey DE, Bowen BW. 2009. The D ...

s are primitive fish which have a jaw structure that resembles that of

tetrapod A tetrapod (; from Ancient Greek :wiktionary:τετρα-#Ancient Greek, τετρα- ''(tetra-)'' 'four' and :wiktionary:πούς#Ancient Greek, πούς ''(poús)'' 'foot') is any four-Limb (anatomy), limbed vertebrate animal of the clade Tetr ...

s rather than

bony fishes Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes (cartila ...

; they also have rudimentary lungs and two slit-like spiracles used for exhalation, and can breathe air when there is insufficient

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

in the water. The West African bichir has an elongated cylindrical body with a maximum length of . It can be distinguished from other members of the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

by having jaws that are about the same length, and in living specimens, having creamy-white irises speckled with black. The

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

consists of 7 to 9 separate finlets each topped with a sharp spine. The pectoral fin is fleshy and has 30 to 32 soft rays and the anal fin has 12 to 15 spines. The dorsal surface and flanks are olive brown with irregular markings of darker brown and the ventral surface is whitish or pale beige. The dorsal and caudal fins are pale beige with dark marks in rows, and black blotches at the base of the spines. The pectoral fins have distinctive black blotches at the base and rows of tiny black spots on the webbing. The pelvic and anal fins are whitish.

Distribution

The West African bichir is a freshwater fish native to tropical West Africa. Its range includes the basins of the

and the

Congo River The Congo River, formerly also known as the Zaire River, is the second-longest river in Africa, shorter only than the Nile, as well as the third-largest river in the world list of rivers by discharge, by discharge volume, following the Amazon Ri ...

, and possibly the Cross River basin in Cameroon. Its typical habitat is swamps and floodplains.

Behaviour

This species is

territorial A territory is an area of land, sea, or space, belonging or connected to a particular country, person, or animal. In international politics, a territory is usually a geographic area which has not been granted the powers of self-government, ...

, with territory holders threatening intruders. The attacker starts the encounter by raising its dorsal fin spines and emitting staccato thumping sounds; both fish may continue by biting at each other, or one may submit and flee, emitting drawn-out moans.

Use in aquaria

''P. retropinnis'' is sometimes kept in aquaria. It will feed on small to medium-sized vertebrates and invertebrates, eating anything it can fit into its mouth.

References

{{Taxonbar, from=Q2747052 Polypteridae Freshwater fish of Africa Fish of the Democratic Republic of the Congo Fish of Gabon Fish described in 1899 Taxa named by Léon Vaillant