Find a Fish
Longfinned Eel
Anguilla reinhardtii Steindachner, 1867
A Longfinned Eel at a depth of 5.5 m, Bellinger River near Thora (west of Bellingen), north-eastern New South Wales, February 2002. Photo © I. Shaw. View larger image.
A Longfinned Eel caught in Eastern Creek, Sydney, NSW. (AMS I.37958-001, 113 cm length). Photo: S. Humphreys © Australian Museum. View larger image.
Head of the above Longfinned Eel. Photo: S. Humphreys © Australian Museum. View larger image.
The tongue and band of teeth on the lower jaw. Photo: S. Humphreys © Australian Museum. View larger image.
Teeth of the upper jaw and the long band of vomerine teeth. Photo: S. Humphreys © Australian Museum. View larger image.
The Longfinned Eel has well developed pectoral fins, a broad head, and a large mouth with fleshy lips.
It can be distinguished from the similar-looking Shortfinned Eel, Anguilla australis, by the length of the dorsal fin. The dorsal fin origin of the Longfinned Eel is well forward of the anal fin origin, whereas the dorsal fin origin of the Shortfinned Eel is above the anal fin origin. The two species also differ in dentition and colouration. The Longfinned Eel usually has olive or brown blotches above and on the sides, fading to pale on the belly. The median fins are brown and the pectoral fins are often yellowish. The Shortfinned Eel is usually a uniform colour and does not have a blotched pattern.
The Longfinned Eel lives in rivers, lakes and swamps, but appears to prefer flowing water.
The species occurs in Australia, New Caledonia and New Zealand. In Australia, it is known from the entire coastal margin of eastern Australia from Cape York to Melbourne and also from northern and eastern Tasmania and Lord Howe Island.
Longfinned Eels undergo a remarkable migration to sea to breed. Adult Longfinned Eel swim downstream to the sea and then migrate to their spawning grounds near New Caledonia. Female eels can have millions of eggs in the ovaries.
Developing leptocephali take about one year to return to the streams of eastern Australia. Young eels (called elvers) then swim upstream and spend a number of years maturing in freshwater.
Landlocked Longfinned Eels (those that cannot return to sea, due to physical barriers) can grow to 3 m in length and weigh 22 kg. They are usually seen at much smaller sizes than this, often about 1m. Males are smaller than females. The Longfinned Eel is primarily carnivorous and eats water beetles, dragonfly larvae (mudeyes), fishes and even young waterfowl.
The Longfinned Eel in the lower images was caught by R. Vella and L. Alsop in January 2000 on hook and line at a depth of 1m in Eastern Creek, Dean Park, Sydney, New South Wales.
View a map of the collecting localities of specimens in the Australian Museum Fish Collection.
Further reading
- Allen, G.R. 1989. Freshwater Fishes of Australia. T.F.H. Publications. Pp. 240.
- Allen, G.R., Midgley, S.H. & M. Allen. 2002. Field Guide to the Freshwater Fishes of Australia. Western Australian Museum. Pp. 394.
- Beumer, J.P. in McDowall, R.M. 1996. Freshwater Fishes of South-Eastern Australia. Reed Books. Pp. 247.
- Merrick, J.R. & G.E. Schmida. 1984. Australian Freshwater Fishes. Biology and Management. John R. Merrick. Pp. 409.
- Park, A. 1986. Incredible Voyagers. Australian Geographic. January-March 1(1): 24-33.
- Tsukamoto, K. 2006. Spawning of eels near a Seamount. Nature. 439: 929.
