; subclass Dipneusti, order Lepidosireniformes)
A monospecific family (Lepidosiren paradoxa) of freshwater fish that have a long, cylindrical body with small scales, small eyes, confluent dorsal and anal fins, and reduced, almost filamentous, pectoral and pelvic fins. It can absorb atmospheric oxygen by utilizing a pair of lungs located beneath the gut. These lungs seem to be even more important for respiration than the gills. During the dry season the fish makes a burrow and becomes dormant. It may reach a length of 1.2 m. It is found in fresh water in S. America.
Subjects: Zoology and Animal Sciences.