Polypterus is the type genus of the bichirs (family Polypteridae), an ancient lineage of ray-finned fish often called living fossils for retaining primitive features lost in most other bony fish, including a functional pair of lungs used alongside gills to breathe air at the surface. The genus is native to freshwater Africa, and the atlas's records span the Democratic Republic of the Congo, Cameroon, Nigeria, the Republic of the Congo, Benin, Chad, Ghana, and Guinea-Bissau. Bichirs have long, cylindrical bodies armored in thick ganoid scales, a row of separate dorsal finlets down the back instead of one continuous fin, and paired pectoral fins they use almost like limbs to prop themselves along the substrate.
Most Polypterus are nocturnal ambush predators that hunt by scent and vibration rather than sight, and several are notorious for wriggling out of any tank without a tightly fitted lid. The genus is a cornerstone of the freshwater oddball hobby: the Senegal bichir (Polypterus senegalus) is by far the most common and beginner-friendly species in the trade, hardy and widely captive-bred, while the ornate bichir (P. ornatipinnis) and barred bichir (P. delhezi) are popular for their bolder patterning, and the giant bichir (P. congicus) is kept mainly by specialists given the large aquarium it eventually needs. The atlas covers 13 species, ranging up to a substantial 38 in in the largest.
Breeding Polypterus in the aquarium is rare but documented: spawning is triggered by rain-like conditions, with the male clasping the female's tail in an embrace to fertilize eggs as they are released and scattered among plants or roots rather than laid in a nest. The resulting larvae hatch with external, feathery gills that are absorbed as the fish matures, another echo of the group's primitive ancestry among ray-finned fish. Conservation-wise the genus is in solid shape, with the great majority of assessed species rated least concern.