[2] All the species occur in freshwater habitats in tropical Africa and the Nile River system, mainly swampy, shallow floodplains and estuaries.

Cladistia, polypterids and their fossil relatives, are considered the sister group to all other extant ray-finned fishes (Actinopteri).

Bichirs have a number of other primitive characteristics, including fleshy pectoral fins superficially similar to those of lobe-finned fishes.

[citation needed] Polypterid reproduction consists of the female laying anywhere from 100 to 300 eggs over the span of a few days, and subsequent fertilization by the male.

They are facultative air-breathers, accessing surface air to breathe when the water they inhabit is poorly oxygenated.

Though predatory, they are otherwise peaceful, preferring to lie on the bottom (they tend to swim when there are lots of large plants present).

In addition to the extinct genus Bawitius, the two living genera, Polypterus and Erpetoichthys, have 14 extant species:[12] Erpetoichthys calabaricus P. retropinnis P. congicus P. ansorgii P. endlicheri P. bichir P. mokelembembe P. ornatipinnis P. weeksii P. teugelsi P. palmas P. senegalus P. delhezi P. polli Order Polypteriformes Suborder Polypterioidei Clade Salamandrophysida