Pacific Shortfin Eel, Anguilla obscura Günther 1872


Other Names: Pacific Shortfinned Eel, Pacific Short-finned Eel, South Pacific Eel

Pacific Shortfin Eel, Anguilla obscura. Source: Queensland Museum. License: all rights reserved

Summary:

The Pacific Shortfin Eel is uniform silver or yellowish to dark brown, becoming paler below. The dorsal fin originates before the anus, just in front of, or level with the anal fin origin, and the jaws reach beyond the eye.

It occurs in coastal drainages from Cape York to about Mackay, Queensland.


Cite this page as:
Martin F. Gomon & Dianne J. Bray, Anguilla obscura in Fishes of Australia, accessed 15 Nov 2018, http://fishesofaustralia.net.au/home/species/1425

Pacific Shortfin Eel, Anguilla obscura Günther 1872

More Info


Distribution

Known from tropical waters of the  Western South Pacific. In Australia, the species occurs from about Captain Billy Creek to Mackay, QLD.

The Pacific Shortfin Eel inhabits freshwater streams, lakes and swamps, favouring coastal lagoons and the lower reaches of rivers. The species is catadromous, and adults migrate from freshwater to the sea to spawn in oceanic waters.

Features

Meristic features: Pectoral fin 14-20; Vertebrae 101-107.

Body, elongate, tubular, snake-like; head moderately small (10-14% SL); eyes dorsally positioned in large adults; mouth moderately large, horizontal, reaching to below posterior edge of eyes; teeth fine, broad band on each side of both jaws and on vomer, vomerine patch much shorter than bands laterally in jaws; gill openings small, just in front of lower half of pectoral fin bases.  Scales tiny, elongate, embedded, arranged in a basket work pattern; lateral line straight, not associated with scales.

Dorsal, anal and caudal fins confluent; dorsal fin origin before the anus, just in front of, or level with anal fin; ventral fins absent; pectoral fin small and fan-like.

Size

Reportedly reaches a total length of 120 cm, but more commonly grows to about 60 cm.

Colour

Varying from silver or yellowish to dark brown on the dorsal and lateral surfaces, becoming paler ventrally.

Feeding

Carnivores, feeding mostly on fishes, molluscs and crustaceans.

Biology

Adults may remain in freshwater environments for 20 years or more before migrating to the sea to breed and then die.

Pacific Shortfin Eels are thought to spawn east of Tahiti, and the larvae are then taken westwards and south via the South Equatorial Current. 

After spawning, the small, pelagic eggs float towards the surface, where they hatch into leptocephalus larvae.

Leptocephali are transparent, elongate, compressed and leaf-like. Leptocephali are believed to be passively transported to the continental shelf by oceanic currents before metamorphosis to the glass eel stage.

During metamorphosis to the glass eel stage, the body shortens and becomes narrower, and the teeth are lost. Glass eels move shoreward into estuaries and rivers.

While in the estuaries, glass eels acclimate to reduced salinities and develop rapidly into fully pigmented elvers with teeth and fully developed stomachs. This is followed by a secondary upstream migration into freshwater.

Fisheries

The species is taken in subsistence fisheries in the Southwest Pacific.

Conservation

IUCN Red List of Threatened Species: Not evaluated.

Species Citation

Anguilla obscura Günther 1872, Proc. Zool. Soc. Lond. 1871(3): 673.

Type locality: Kanathea, Fiji Islands.

Author

Martin F. Gomon & Dianne J. Bray

Resources

Atlas of Living Australia 

Australian Faunal Directory

CAAB Codes for Australian Aquatic Biota

Catalog of Fishes  

OZCAM – Online Zoological Collections of Australian Museums

Pacific Shortfin Eel, Anguilla obscura Günther 1872

References


Allen, G.R. 1989. Freshwater Fishes of Australia. T.F.H. Publications, 240 pp.

Allen, G.R., Midgley, S.H. & M. Allen. 2002. Field Guide to the Freshwater Fishes of Australia. Western Australian Museum, 394 pp.

Beumer, J.P, R.G. Pearson & L.K. Penridge. 1981. Pacific shortfinned eel, Anguilla obscura Gunther, 1871 in Australia: Recent records of its distribution and maximum size. Proc. R. Soc. Queensland 92: 85-90.

Günther A. 1872. Report on several collections of fishes recently obtained for the British Museum. Proc. Zool. Soc. Lond. 1871(3): 652-675.

Hoese, D.F. & J.E. Gates. 2006. Family Anguillidae, p. 235-237. In Beesley, P.L. & A. Wells. Zoological Catalogue of Australia, Volume 35. ABRS & CSIRO Publishing. Part 1.

Matsui, I., T. Takai & A. Kataaoka. 1970. Leptocephalae of the eel Anguilla obscura found in the stomachs of skipjack tuna Katsuwonus pelamis caught near New Guinea. J. Shimonoseki Univ. Fish. 19: 2528.

Nelson, J.S. 2006. Fishes of the world. John Wiley & Sons, New Jersey. 601 pp.

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.

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

Pusey, B. J., M. J. Kennard & J. Bird. 2000. Fishes of the dune fields of Cape Flattery, northern Queensland and other dune systems in north-eastern Australia. Ichthyological Exploration of Freshwaters 11(1): 65-74.

Richardson. J. 1848. In Richardson J. & Gray J.E. (eds.) The zoology of the voyage of H.M.S. Erebus and Terror during 1839-43. Part VII.

Teng, H.-Y., Y.-S. Lin & C.-S. Tzeng. 2009. A new Anguilla species and a reanalysis of the phylogeny of freshwater eels. Zoological Studies 46(6): 808-822.

Quick Facts


CAAB Code:37056004

Biology:Leptocephalus larvae

Biology:Migratory - catadromous

Habitat:Freshwater to marine

Max Size:1.2 metres

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Species Maps

CAAB distribution map