; superorder Cephalaspidomorpha, order Lepidosireniformes)
A small family of freshwater fish that can breathe air with the aid of a pair of air sacs or lungs. They have a somewhat rounded body and long, filamentous, pectoral and pelvic fins. The gills are functional, but poorly developed: the fish often have to rely wholly on their lungs as they tend to live in stagnant water low in oxygen. During the dry season they aestivate in deep burrows in the muddy bottom of the swamp, surrounding themselves with a thin cocoon. There are four species, living in African rivers.
Subjects: Zoology and Animal Sciences.