Longfin Eel, Anguilla reinhardtii Steindachner 1867


Other Names: Australian Longfinned Eel, Conger Eel, Freshwater Eel, Long-fin Eel, Longfinned Eel, Long-finned Eel, Marbled Eel, River Eeel, River Eel, Speckled Longfin Eel, Spotted Eel

A Longfin Eel, Anguilla reinhardtii, in the Royal botanic Gardens, Sydney, New South Wales. Source: d_kluza / iNaturalist. License: CC by Attribution-NonCommercial-NoDerivatives

Summary:

Longfin Eels are large predatory carnivores with long cylindrical bodies and united dorsal, caudal and anal fins. They spend most of their lives in freshwater, migrating to deep waters of the Coral Sea to breed. As their transparent leptocephalus larvae grow, they metamorphose into glass eels.

Great video of "Ellie", a Longfin Eel in the Sydney Botanic Gardens.

River Monsters: The Longfin Eel Migration in New Zealand.

Longfin Eels in New Zealand.


Cite this page as:
Martin F. Gomon & Dianne J. Bray, Anguilla reinhardtii in Fishes of Australia, accessed 27 Jul 2017, http://fishesofaustralia.net.au/Home/species/1426

Longfin Eel, Anguilla reinhardtii Steindachner 1867

More Info


Distribution

Known from the tropical and temperate Southwestern Pacific, from New Caledonia, New Guinea, northwestern New Zealand, Lord Howe Island and Australia. Widespread in the coastal drainages of eastern Australia from the Jardine River, Cape York, Qld (10°44’S) southwards to Melbourne, Vic, and northern and eastern Tasmania. Longfin Eels live in a wide range of freshwater habitats, including rivers, streams, lakes, swamps and floodplains, although they prefer preferring flowing water. They are also known to inhabit deeper waters of freshwater reservoirs. The species is catadromous and adults migrate to the deep oceanic waters of the Coral Sea below 400 m to spawn. Glass eels and elvers are found in estuarine areas, moving upstream as the mature.

Features

Pectoral fins 16-20; Vertebrae 104-110 

Body large, elongate, cylindrical (depth 6-8% SL); head moderately small (12-18% SL); eyes small; mouth large, horizontal, usually reaching just beyond eyes; teeth fine, a narrow band in jaws and on vomer, vomerine patch about as long as bands laterally in jaws; maxillary teeth separated by a toothless groove; gill openings small, just forward of lower half of pectoral fin bases; lateral line straight, not associated with scales. Scales tiny, elongate, embedded, arranged in a basket-work pattern. Dorsal, caudal and anal fins united to form one continuous fin; dorsal fin origin well in front of vertical line drawn through anus (distance between the two 8-14% TL); pectoral fins prominent; ventral fins absent.

Size

Although Longfin Eels commonly reach lengths of about 100-150 cm and weigh 1-2 kg, land-locked individuals prevented from migrating downstream may reach 300 cm and weigh up to 22 kg. Males are generally smaller than females, growing to about 65 cm and weighing about 600 g.

Colour

Adults and elvers are distinctly mottled or marbled with olive-green to brown markings, and a paler underside. Adults returning to sea are overall silvery, with a mottled underside, and often yellowish pectoral fins. Leptocephali and glass eels are mostly transparent with the muscle bands visible internally.

Feeding

Longfin eels are carnivores, and are the top predator in many habitats. They usually feed at night on fishes, crustaceans, molluscs and insects and occasionally juvenile waterfowl.

Biology

The sexes separate and Pease et al (2004) found no evidence of hermaphroditism in Longfin Eels. Adults may remain in freshwater environments for more than 50 years before migrating to the Coral Sea to breed in depths greater than 400 mand then die.

Eggs are small and pelagic, float upwards toward the surface. Leptocephali larvae are transparent, elongate and compressed and leaf-like. Leptocephali are believed to be passively transported to the continental shelf by oceanic currents before they metamorphose into transparent eel-shaped "glass eels". During this metamorphosis, a reduction in body length and width and loss of teeth occurs. Glass eels enter estuaries at about 58 mm TL, where they undergo physiological changes to cope with reduced salinities. The eels develop rapidly as they migrate up the estuaries, becoming fully pigmented "elvers" with teeth and well-developed stomachs. This is followed by a secondary upstream migration into freshwater.

Fisheries

Longfin eels have long been a popular food source for Aboriginal people in eastern Australia and have strong cultural significance. Eels have been caught with a variety of methods, including fish traps, lures, hook and line and natural poisons derived from plants.

Longfin Eels have been targeted commercially in Australia since the 1950's or 60's. Although four commercial fisheries target Longfin Eels in eastern Australia, most are harvested in the estuarine trap fishery which targets large yellow eels. Relatively small numbers of glass eels (post-larvae migrating from the sea to freshwaters) are caught with fyke nets in upper estuarine areas to be grown up in the aquaculture industry. Other small fisheries targets small male yellow and juvenile eels and larger eels in impoundments. 

Most eels caught in the estuarine trap fishery are exported live to China (including Hong Kong) and elsewhere in Asia.

Conservation


Remarks

The Longfin Eel may live to more than 50 years.

Similar Species

The Longfin Eel is readily distinguished from the Shortfin Eel, Anguilla australis, by its spotted body pattern and length of the dorsal fin, which commences well in front of the anal fin.

Species Citation

Anguilla reinhardtii Steindachner 1867, Sber. Akad. Wiss. Wien 55(1): 15, Figs. a-b,  Fitzroy River, Rockhampton, Queensland, Australia.

Author

Martin F. Gomon & Dianne J. Bray

Longfin Eel, Anguilla reinhardtii Steindachner 1867

References


Allen, G.R. 1989. Freshwater Fishes of Australia. T.F.H. Publications.

Allen, G.R., Midgley, S.H. & M. Allen. 2002. Field Guide to the Freshwater Fishes of Australia. Western Australian Museum.

Aoyama, J., Mochioka, N., Otake, T., Ishikawa, S., Kawakami, Y., Castle, P. and Tsukamoto, K. 1999. Distribution and dispersal of anguillid leptocephali in the western Pacific Ocean revealed by molecular analysis. Marine Ecology Progress Series 188, 193-200.

Beumer, J. P. (1979). Feeding and movement of Anguilla australis and A. reinhardtii in Macleods Morass, Victoria, Australia. Journal of Fish Biology 14, 573-592.

Beumer, J. P. (1983). Eels. Victorian Naturist 100, 168-171.

Beumer, J. P. (1996). Freshwater eels. pp. 39-43. In McDowall, R.M. (ed.) Freshwater Fishes of South-eastern Australi . Reed: Sydney, Australia.

Beumer, J. P. & Sloane, R.D. 1990. Distribution and abundance of glass-eels I spp. in east Australian waters. Int. Revue ges. Hydrobiol. 75: 721-736.

Castle, P. H. J. 1963. Anguillid leptocephali in the Southwest Pacific. Zoology Publications from Victoria University of Wellington 33: 1-14.

Hoese, D.F., Bray, D.J., Paxton, J.R. & G.R. Allen. 2006. Fishes. In Beesley, P.L. & A. Wells. (eds) Zoological Catalogue of Australia. Volume 35. ABRS & CSIRO Publishing: Australia. parts 1-3, pages 1-2178.

Kailola, P. J., Williams, M. J., Stewart, P. C., Reichelt, R. E., McNee, A. and Grieve, C. (1993). Australian Fisheries Resources. Bureau of Resource Sciences, Department of Primary Industries and Energy, and the Fisheries Research and Development Corporation: Canberra, Australia.

Merrick, J.R. & G.E. Schmida. 1984. Australian Freshwater Fishes. Biology and Management. John R. Merrick.

Park, A. 1986. Incredible Voyagers. Australian Geographic. January-March 1(1): 24-33.

Pease, B.C. (ed.) 2004. Description of the biology and an assessment of the fishery for adult longfinned eels in NSW. Final Report to Fisheries Research and Development Corporation. Project No. 1998/127. NSW Department of Primary Industries - Fisheries Final Report Series No. 69. 167pp.

Pease, B. C., Reynolds, D. P. and Walsh, C. T. 2003. Validation of otolith age determination in Australian longfinned river eels, Anguilla reinhardtii. Marine and Freshwater Research 54: 995-1004.

Pusey, B.J., M.J. Kennard and A.H. Arthington (2004).  Freshwater Fishes of North-Eastern Australia.  CSIRO Publishing, Collingwood, Victoria. 684 pp.

Roughley, T. C. (1955). Fish and Fisheries of Australia. Angus and Robertson: Sydney, Australia.

Shiao, J.-C., Tzeng, W. N., Collins, A. & Iizuka, Y. 2002. Role of marine larval duration and growth rate of glass eels in determining the distribution of Anguilla reinhardtii and A. australis on Australian eastern coasts. Marine and Freshwater Research 53: 687-695.

Silberschneider, V. 2005. Recruitment and age dynamics of Anguilla australisand A. reinhardtii glass eels in the estuaries of New South Wales. PhD thesis, University of Technology Sydney. PDF

Sloane, R.D. 1984. Distribution, abundance, growth and food of freshwater eels (Anguilla spp.) in the Douglas River, Tasmania. Australian Journal of Marine and Freshwater Research 35(3): 325-339.

Sloane, R.D. 1984. Distribution and abundance of freshwater eels (Anguilla spp.) in Tasmania. Australian Journal of Marine and Freshwater Research 35: 463-470.

Smith, D.G. 1999 Anguillidae. Freshwater eels. p. 1630-1636. In K.E. Carpenter and V.H. Niem (eds.) FAO species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Vol. 3. Batoid fishes, chimaeras and bony fishes part 1 (Elopidae to Linophrynidae). FAO, Rome.

 Tsukamoto, K. 2006. Spawning of eels near a Seamount. Nature. 439: 929.

Walsh, C. T., Pease, B. C. and Booth, D. J. (2003). Sexual dimorphism and gonadal development of the Australian longfinned river eel. Journal of Fish Biology 63, 137-152.

Walsh, C. T., Pease, B. C. and Booth, D. J. (2004). Variation in the sex ratio, size and age of Australian longfinned river eels, Anguilla reinhardtii, within and among coastal catchments of south-eastern Australia. Journal of Fish Biology 64, 1297-1312.

Silberschnieder, V., Pease, B.C. & Booth, D.J. 2004. Estuarine habitat preferences of Anguilla australis and A. reinhardtii glass eels as inferred from laboratory experiments. Environmental Biology of Fishes 71(4): 395-402.

Quick Facts


CAAB Code:37056002

Biology:Migratory

Fishing:Commercial species

Habitat:Freshwater/marine larvae

Max Size:To 300 cm (landlocked)

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CAAB distribution map