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Lungfish

Australian Lungfish

The Australian lungfish is the most primitive of the modern lungfish and has changed little over the past several million years. The body is long, slim, and has very large scales, and broad, flipper-like pectoral and pelvic fins. A dorsal fin is lacking. The tail of the Australian lungfish is most unusual, and consists of a rim of fin material around the rear end of the body.

The Australian lungfish has four big teeth which look as though they have grown together into fan-shaped crushing plates somewhat resembling a rooster's comb. Prior to the discovery of the first Australian lungfish around 1869, large teeth of this type had only been found The evolution of lungfish. Illustration by Hans & Cassidy. Courtesy of Gale Group. in the fossil record. These teeth are an efficient adaptation for shearing and crushing. Neoceratodus is a carnivorous fish, feeding on small mollusks, crustaceans, and other aquatic invertebrates. Its paddle-like fins are unsuitable for crawling; however, the lungfish can stand on these appendages, using them like legs underwater. The Australian lungfish has a single lung located above the gut which is slightly less developed than the lungs of the African and South American species.

Also known as the Burnett salmon, the Australian lungfish inhabits rivers that generally remain as permanent watercourses and do not dry out periodically, although the dissolved oxygen content does vary considerably. This lungfish uses its gills more than the other two types of lungfishes and, in well-oxygenated water, does not need to return to the surface for air. However, this species is less tolerant of poor water quality and can efficiently use its lung to breathe fresh air from the atmosphere when necessary. The Australian lungfish does not aestivate in a cocoon of mud like the African lungfish. Instead the Australian lungfish spawns in shallow water in the fall, laying its eggs on water plants. The native Australians call this lungfish dyelleh.


Resources

Books

Whiteman, Kate. World Encyclopedia of Fish & Shellfish. New York: Lorenz Books, 2000.


Betsy A. Leonard

KEY TERMS

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Aestivation

—A state of dormancy or torpor during the dry season, a period of drought.

Dorsal

—Of, toward, on, in, or near the back.

Pectoral

—Pertaining to the breast or chest.

Pelvic

—Of, in, near, or pertaining to the pelvis; in fish, either of a pair of lateral hind fins; also called the ventral fin.

Zoogeographer

—A person making the biological study of the geographical distribution of animals.

Additional topics

Science EncyclopediaScience & Philosophy: Linear expansivity to Macrocosm and microcosmLungfish - African And South American Lungfish, Australian Lungfish