The lungfish has small gills, but must have access to air or it drowns. About once every twenty minutes it comes to the surface to swallow a gulp of air, passing the gas into a pair of air bladders or lungs that open into the gullet. Among the many other unusual features of structure found in the lungfish are a pair of nostrils that open from the exterior into the mouth; in this respect lungfish differ from almost all other kinds of fishes. The lungfish has a long body with long dorsal and anal fins that seem to come together in a sharp point to form the tail. The pectoral and pelvic fins are merely long, tapering ribbons. Scales are small and completely embedded in the skin. In color it is brown or tan with black or dark brown mottling.
The male lungfish prepares a clear area among dense plant growth on the muddy bottom, and there the female lays her eggs. These are about one-eighth of an inch in diameter and are guarded by the male and kept supplied with fresh water by vigorous movements of his tail. After about eight days they hatch, and the young are also guarded for awhile. Young lungfish are unusual in having external gills – four pairs of them – like those seen in a number of amphibians. As the fish mature, these organs gradually disappear. Lungfish attain a size of at least three feet. They are a popular food with native Africans.
The African lungfish is widely distributed in the fresh waters of tropical Africa. There are two other closely related African species, one of which reaches a length of at least six feet.