The South American lungfish (Lepidosiren paradoxa), also known as the American mud-fish or scaly salamanderfish, is the only lungfish species found in the swamps and slow-moving waters of the Amazon, Paraguay, and lower Paraná River basins. An obligate air-breather, it is unique in its family, Lepidosirenidae. In Brazil, it is commonly referred to as piramboia, meaning "snake-fish" in the indigenous Tupi language.
Taxonomically, this species is closely related to African lungfishes, and both families are believed to have diverged during the Early Cretaceous. While some researchers propose grouping Lepidosiren and Protopterus together, they are generally classified as distinct families.
Physically, immature lungfish exhibit gold spots on a black background, which fade to brown or gray as they mature. Their unique anatomical features include fused premaxillary and maxillary bones and an elongated, eel-like body that can reach lengths ranging from 3-4 feet. Their fin structure is distinctive, with a single bone connection resembling that of land-dwelling vertebrates. Adults have greatly reduced gills, which are nearly non-functional.
In the wild, juvenile lungfish primarily feed on insect larvae and snails, while adults have an omnivorous diet that includes algae and shrimp. During the dry season, they burrow into the mud to survive, creating a moisture-retaining chamber. Adapted to cope with both drought and floods, they emerge during the rainy season to mate and build nests for their young. Remarkably, L. paradoxa has one of the largest genomes among living species, containing 91 billion bases.
Keeping South American lungfish in captivity requires specific conditions to mimic their natural habitat. They thrive in spacious aquariums with plenty of hiding spots and subdued lighting. Since they are obligate air-breathers, it is essential to provide access to the water's surface. A varied diet, including high-quality pellets, live foods, and vegetables, is crucial for their health. Additionally, maintaining stable water parameters and regular water changes is vital to support their well-being. Proper care and an understanding of their unique needs can lead to a rewarding experience for experienced aquarists.
