Queensland lungfish

The Queensland lungfish (Neoceratodus forsteri), also known as the Australian lungfish, Burnett salmon and barramunda, is a surviving member of the family Neoceratodontidae and order Ceratodontiformes. It is one of only six extant lungfish species in the world. Endemic to Australia, the Neoceratodontidae are an ancient family belonging to the class Sarcopterygii, or lobe-finned fishes. Fossil records of this group date back 380 million years, around the time when the higher vertebrate classes were beginning to evolve. Fossils of lungfish almost identical to this species have been uncovered in northern New South Wales, indicating that Neoceratodus has remained virtually unchanged for well over 100 million years, making it a living fossil and one of the oldest living vertebrate genera on the planet. It is one of six extant representatives of the ancient air-breathing Dipnoi (lungfishes) that flourished during the Devonian period (about 413–365 million years ago) and is the outgroup to all other members of this lineage.The five other freshwater lungfish species, four in Africa and one in South America, are very different morphologically from N. forsteri. The Queensland lungfish can live for several days out of the water, if it is kept moist, but will not survive total water depletion, unlike its African counterparts. The small settlement of Ceratodus, Queensland derives its name from that of the Queensland lungfish. The species was named in honour of the squatter and politician William Forster. The Queensland lungfish is native only to the Mary and Burnett River systems in south-eastern Queensland. It has been successfully distributed to other, more southerly rivers, including the Brisbane, Albert, Stanley, and Coomera Rivers, and the Enoggera Reservoir in the past century. The Queensland lungfish has also been introduced to the Pine, Caboolture, and Condamine Rivers, but current survival and breeding success are unknown. Formerly widespread, at one time at least seven species of lungfish were in Australia. This species lives in slow-flowing rivers and still water (including reservoirs) that have some aquatic vegetation present on banks. It occurs over mud, sand, or gravel bottoms. Australian lungfish are commonly found in deep pools of depths between 3 and 10 m and live in small groups under submerged logs, in dense banks of aquatic macrophytes, or in underwater caves formed by the removal of substrate under tree roots on river banks. The lungfish is tolerant of cold, but prefers waters with temperatures between 15 and 25 °C. The Queensland lungfish is incapable of surviving complete desiccation of its habitat, although it can live out of water for several days if the surface of its skin is constantly moist. Unlike the African species, Protopterus, it does not survive dry seasons by secreting a mucous cocoon and burying itself in the mud. The Queensland lungfish is essentially a sedentary species, spending its life within a restricted area. Its home range rarely extends beyond a single pool or, occasionally, two adjacent pools. It does not follow a set migratory path, but may actively seek out suitable spawning habitats between July and December.