Lungfish are freshwater fish, normally found in still or slow flowing pools, living only in Africa, South America, and Australia. The Australian lungfish grows to about 1.5 m in length and over 40 kg. It occurs naturally in the Burnett and Mary River systems in Queensland and has been introduced into other rivers and dams in south-eastern Queensland and north-eastern New South Wales.
The Australian lungfish is a carnivore eating frogs, tadpoles, small fishes, snails, shrimp and earthworms. They use use electroreception to locate hidden prey. Unlike the African and South American species the Australian lungfish has a single lung compared to paired lungs. Usually they breathe using gills but in drought conditions they can come to the surface and breathe air. Only the Australian lungfish can breathe using its gills.
The Australian lungfish spawns at night from August to December. Fertilized eggs are attached to aquatic plants and hatching takes about three weeks. Growth is very slow, with young reaching 6 cm in length after 8 months and 12 cm after two years.
The Australian Lungfish is a protected species and may not be captured without a special permit.
African and South American lungfish are capable of surviving seasonal drying out of their habitats by burrowing into mud and aestivating (similar to hibernation taking place during times of heat and dryness) throughout the dry season. Changes in physiology allow the lungfish to slow its metabolism to as little as 1/60th of the normal metabolic rate.
Lungfish can be extremely long-lived, one kept in captivity is around 80 years old.