The South American Lungfish (Lepidosiren paradoxa) is the single species of lungfish found in swamps and slow-moving waters of South America. Notable as an obligate air-breather, it is the sole member of its family Lepidosirenidae.

Like the other lungfishes, this species has an elongate, almost eel-like body. It may reach a length of 125 cm (4 ft). The pectoral fins and thin and threadlike, while the pelvic fins are somewhat larger, and set far back.

Juvenile lungfish feed on insect larvae and snails, while adults are omnivorous, adding algae and shrimps to their diet. The fishes' usual habitats disappear during the dry season, so they burrow into the mud and make a chamber about 30-50 cm down, leaving a couple of holes to the surface for air.

When the rainy season begins, they come out of hibernation and begin mating. The parents build a nest for the young, which resemble tadpoles and have four external gills. In order to enrich the oxygen in the nest, the male develops structures on the pectoral fins that release additional oxygen into the water. The young become air-breathing at about 7 weeks.

External link

• FishBase entry for South American Lungfish