Australian Lungfish

Introduction

Unlike most fishes, the Australian Lungfish has the unqiue ability to breathe air using a single lung when during dry periods streams become stagnant, or when water quality changes.

Identification

The Australian Lungfish has a long, heavy body with large scales. It has small eyes and paddle-like pectoral fins and pelvic fins. Its dorsal fin starts midway along the back and is continuous with the caudal and anal fins.

The species is usually olive-green to brown on the back and sides with some scattered dark blotches, and whitish ventrally.

The species was described in 1870 by Australian Museum staff member Gerard Krefft.

Habitat

The Australian Lungfish is normally found in still or slow flowing pools in river systems of south-eastern Queensland.

Distribution

It occurs naturally in the Burnett and Mary River systems although has been introduced into other rivers and reservoirs in south-eastern Queensland.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Click on the map for detailed information. Source: Atlas of Living Australia.

Feeding and diet

Food items include mainly frogs, tadpoles, small fishes, snails, shrimp and earthworms. It will also eat plant material. The eyesight of the Australian Lungfish has been reported to be poor and the location of prey was thought to be based on the sense of smell rather than sight. The recent work of Watt et al (1999) has shown that the Australian Lungfish can use electroreception to locate hidden prey. Their research on the anatomy of this species has shown the presence of organs similar to those used for the detection of electric signals in other fishes, such as sharks.

Other behaviours and adaptations

The Australian Lungfish has a single lung, whereas all other species of lungfishes have paired lungs. During dry periods when streams become stagnant, or when water quality changes, lungfishes have the ability to surface and breathe air. When the Australian Lungfish surfaces to empty and refill its lung the sound is reportedly like that of the "blast from a small bellows". Under most conditions, this species breathes exclusively using its gills.

Life history cycle

The species can live to at least 20-25 years of age. The Shedd Aquarium's Australian Lungfish, affectionately known as 'Granddad' (see image) lived to over 80 years of age and was possibly the oldest fish in captivity. He was finally euthanised on 5 Feb 2017.

Breeding behaviours

This species spawns at night from August to December with peak activity in October. Fertilized eggs are stuck 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.

Conservation status

The Australian Lungfish is a protected species and may not be captured without a special permit. It is also listed in Appendix 2 of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Australia is a signatory to CITES and has strict regulations on the export of the Australian Lungfish.

Fossils description

The lungfishes first appeared in the fossil record 380 million years ago. They are relics of ancient fish groups that were related to the ancestors of amphibians, reptiles, birds and mammals.

Evolutionary relationships

Worldwide, there are six species of lungfishes. Four species in the genus Protopterus(Family Protopteridae) are found in Africa. One species Lepidosiren paradoxa (Family Lepidosirenidae) is recorded from South America. The Australian Lungfish is the only species in the Family Ceratodontidae.

The African lungfish Protopterus annectens (see image) is known for its ability to bury in the mud. At the onset of the dry season when water bodies dry up, this species is able to secrete large quantities of mucous. The mucous hardens to form a cocoon in which the fish stays dormant for several months. Other species of African lungfishes also have this ability to varying extents.

The South American Lungfish can only breathe air. It can survive for months in a resting chamber of moist mud and mucous. The Australian Lungfish does not bury in the mud or form a cocoon and cannot survive for more than a few days out of water.

References

• Allen, G.R. 1989. Freshwater Fishes of Australia. T.F.H. Publications. Pp. 240.
• Anon, 1999. FOSSIL AND MODERN BONY FISH [online - pages maintained by George Barrett and Ralph Maddox].
• Bruton, M.N. in Paxton, J.R. & W.N. Eschmeyer (Eds). 1994. Encyclopedia of Fishes. Sydney: New South Wales University Press; San Diego: Academic Press [1995]. Pp. 240.
• Anon, 2003. Nationally threatened species and ecological communities. Australian Lungfish (Neoceratodus forsteri). Environment Australia website. http://www.ea.gov.au/biodiversity/threatened/
• infosheets/pubs/lungfish.pdf. (pdf 195k)
• Joss, J. 2002. Australian Lungfish, Neoceratodus forsteri. Fishes of Sahul. Journal of the Australia New Guinea Fishes Association. 16(2): 836-844.
• Joss, J. 2004. Queensland Lungfish. Trouble for a 'window on the past'. ANGFA News. 18: 1, 4-5.
• Kind, P., Grigg, G., Warburton, K., & C. Franklin. 1999. Habitat utilisation and movement patterns of the Queensland lungfish (Neoceratodus forsteri). [online - CENTRE FOR CONSERVATION BIOLOGY Science for Conservation of Our Natural Heritage]
• Merrick, J.R. & G.E. Schmida. 1984. Australian Freshwater Fishes. Biology and Management. John R. Merrick. Pp. 409.
• Nelson, J.S., 1994. Fishes of the World, third edition. John Wiley & Sons, Inc. Pp: 600.
• Watt, M, C.S. Evans & J.M.P. Joss. 1999. Use of electroreception during foraging by the Australian Lungfish. Animal Behaviour. 58: 1039-1045. [online at http://galliform.bhs.mq.edu.au/Watt_et_al.html]