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, from Angusvale, Gippsland Lakes, Mitchell River National Park, Victoria, November 2014. Source: David Paul / Museums Victoria. License: CC by Attribution-NonCommercial

Summary:

A large mottled or marbled eel with olive-green to brown markings, and a paler underside. Longfin Eels spend most of their lives in freshwater, migrating to spawn in deep waters of the Coral Sea. As their transparent leptocephalus larvae grow, they metamorphose into glass eels, then pigmented elvers as they reach coastal waters. Longfin Eels then develop into yellow eels, before transforming into silver eels  and returning to freshwater streams.

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

Migrating glass eels - juvenile Longfin Eels - in a very small mangrove creek at the northern end of Palm Cove, Cairns, Australia.

River Monsters: The Longfin Eel Migration in New Zealand.

Longfin Eels in New Zealand.


Cite this page as:
Gomon, M.F. & Bray, D.J. 2021, Anguilla reinhardtii in Fishes of Australia, accessed 11 Aug 2022, https://fishesofaustralia.net.au/home/species/1426

Longfin Eel, Anguilla reinhardtii Steindachner 1867

More Info


Distribution

Widespread in the coastal drainages of eastern Australia from Cape York, Queensland, to Melbourne, Victoria, and northern and eastern Tasmania; also Lord Howe Island in the Tasman Sea. Elsewhere the species occurs in the tropical and temperate Southwestern Pacific: New Caledonia, northwestern New Zealand, Papua New Guinea and Vanuatu.

Longfin Eels prefer flowing waters, and commonly occur in riverine habitats, from river mouths to headwater streams. They also inhabit in lakes, swamps and floodplains, and deep 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, before moving upstream as silver eels.

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 may weigh 1-2 kg, land-locked individuals that are 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. 

The species is catadromous, and adults may remain in freshwater environments for more than 50 years before migrating to the Coral Sea to spawn in depths greater than 400 m.

The small pelagic eggs float towards the surface. The leptocephalus larvae are transparent, elongate, compressed and leaf-like. Leptocephali are believed to be transported to the continental shelf by oceanic currents before metamorphosing into transparent eel-shaped "glass eels", followed by pigmented elvers as they reach coastal waters.

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 estuaries, and become fully pigmented "elvers" with teeth and well-developed stomachs. This is followed by a second upstream migration into freshwater as silver eels with a dark dorsal surface and pale underside.

Fisheries

Freshwater 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

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.

Etymology

The species is presumably named in honour of Danish zoologist and herpetologist Johannes Theodor Reinhardt.

Species Citation

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

Author

Gomon, M.F. & Bray, D.J. 2021

Resources

Atlas of Living Australia

Longfin Eel, Anguilla reinhardtii Steindachner 1867

References


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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 Australia. Reed: Sydney, Australia.

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

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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.

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Quick Facts


CAAB Code:37056002

Behaviour:To 300 cm (landlocked fish)

Biology:Migratory

Conservation:IUCN Least Concern

Fishing:Commercial species

Habitat:Freshwater/marine larvae

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