Lepidosiren Paradoxa

Datasheet

General Description

Lungfish are intriguing aquarium species known for their ability to survive in extreme conditions. They are ancient fish, virtually unchanged for millions of years. The South American Lungfish is the only lungfish species in South America, representing a unique genus in the class Sarcopterygii. South American Lungfish exhibit remarkable adaptations to survive dry periods, resorting to aestivation by encasing themselves in a mucous cocoon when water levels drop. They possess both gills and lungs and are obligatory air-breathers, needing access to atmospheric air to survive. With limb-like fins resembling tetrapod legs, lungfish can even move across land if necessary. They have a prolonged lifespan, demanding a considerable long-term commitment from aquarists.

Aquarium Setup

The ideal tank setup for South American Lungfish includes minimal water movement and sturdy decorations such as roots, branches, or large rocks to prevent displacement. The tank cover must be secure with no gaps to prevent escapades, as lungfish have a tendency to explore. Sand or mud substrate is beneficial, but not necessary, while dim lighting is recommended. Adequate space, around 6 inches, between the water surface and the tank cover is required for the lungfish to access atmospheric air. A robust filtration system is essential due to the substantial waste generated by the lungfish. A sump-type filtration setup is preferable to accommodate the equipment outside the tank, reducing the risk of damage by the fish.

Behaviour

South American Lungfish are generally peaceful towards tankmates larger than themselves. However, they may display aggression towards other bottom-dwelling species. Suitable companions can include big catfish, bichirs, larger characins, and cichlids, but maintaining them in a community tank requires a vast aquarium to accommodate their size and potential territorial behaviors.

Feeding and Diet

Being omnivorous, South American Lungfish feed on a variety of foods like fish, shellfish, amphibians, and plant matter. In an aquarium, they can be offered prawns, mussels, algae wafers, and other vegetable-based foods. Larger specimens may consume whole fish like trout. Feeding frequency should decrease as the fish grows, with adult lungfish requiring only one meal per week. It is essential to avoid feeding mammal meat like beef heart and live feeder fish, as they can lead to health issues in the fish.

Reproduction & Dimorphism

Reproduction of the South American Lungfish is not well-documented in the hobby. In the wild, they spawn during the wet season, with males guarding the eggs in a nest constructed within a burrow. After hatching, the fry possess external gills until their lungs fully develop, typically around two months. The offspring exhibit striking black coloration with bright gold spots. Sexual dimorphism of this species is unknown.

Habitat and Distribution

South American Lungfish are found in slow-moving and stagnant waters such as weedy creeks, swamps, and tributaries. Their habitat includes hypoxic environments and areas that dry out completely during the dry season. The species is widely distributed across the Amazon, Rio Paraguay, and lower Rio Paraná basins, spanning various countries in South America.