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.


Cite this page as:
Gomon, M.F. & Bray, D.J. 2021, Anguilla obscura in Fishes of Australia, accessed 29 Nov 2021, https://fishesofaustralia.net.au/home/species/1425

Pacific Shortfin Eel, Anguilla obscura Günther 1872

More Info


Distribution

Coastal drainages from the Watson River, NE of Aurukun, Gulf of Carpentaria, to Fraser Island, Queensland. Elsewhere the species occurs in the tropical, south-west Pacific: Indonesia (Papua), Papua New Guinea, Solomon Islands, New Caledonia, Cook Islands, Fiji, Samoa, Tonga, Vanuatu, French Polynesia.

Inhabits freshwater streams, lakes and swamps, favoring 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

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

Feeds mostly on fishes, molluscs and crustaceans.

Biology

Adults may remain in freshwater environments for 20 years or more before migrating to the sea to spawn.

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


Species Citation

Anguilla obscura Günther 1872, Proc. Zool. Soc. Lond. 1871(3): 673. Type locality: Kanathea, Fiji Islands.

Author

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

Resources

Atlas of Living Australia 

Australian Faunal Directory

Catalog of Fishes 

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, Pearson, R.G. & Penridge, L.K. 1981. Pacific shortfinned eel, Anguilla obscura Gunther, 1871 in Australia: Recent records of its distribution and maximum size. Proceedings of the Royal society of  Queensland 92: 85-90.

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

Ege, V. 1939. A revision of the genus Anguilla Shaw: a systematic, phylogenetic and geographical study. Dana Reports 16: 1-256 figs 1-53 pls 1-6

Gubili, C., Schabetsberger, R., Poellabauer, C., Bates, B., Wagstaff, R.M., Woodward, L.M., Sichrowsky, U., Scheck, A., Boseto, D.T., Feunteun, E., Acou, A. & Jehle, R. 2018. High genetic diversity and lack of pronounced population structure in five species of sympatric Pacific eels. Fisheries Management and Ecology 26(1): 31–41.

Günther A. 1872. Report on several collections of fishes recently obtained for the British Museum. Proceedings of the Zoological Society of London 1871(3): 652-675.

Jellyman, D.J. 1991. Biology of the shortfinned eel Anguilla obscura in Lake Te Rotonui, Mitiaro, Cook Islands. Pacific Science 45(4): 362-373.

Kuroki, M., Aoyama, J., Miller, M.J., Watanabe, S., Shinoda, A., Jellyman, D.J., Feunteun, E. & Tsukamoto, K. 2008. Distribution and early life-history characteristics of anguillid leptocephali in the western South Pacific. Australian Journal of Marine and Freshwater Research 59: 1035−1047.

Merrick, J.R. & Schmida, G.E. 1984. Australian Freshwater Fishes Biology and Management. Sydney : J.R. Merrick 409 pp. figs 280 col. figs.

Schabetsberger, R., Økland, F., Aarestrup, K., Kalfatak, D., Sichrowsky, U., Tambets, M., Dall’Olmo, G., Kaiser, R. & Miller, P.I. 2013. Oceanic migration behaviour of tropical Pacific eels from Vanuatu. Marine Ecology Progress Series 475: 177-190.

Smith, D.G. 1999. Families Halosauridae, Notacanthidae, Lipogenyidae, Anguillidae, Moringuidae, Chlopsidae, Myrocongridae. pp. 1625-1642 in Carpenter, K.E. & Niem, V.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 3 pp. 1397-2068.

Pike, C., Crook, V., Jacoby, D. & Gollock, M. 2020. Anguilla obscura (amended version of 2019 assessment). The IUCN Red List of Threatened Species 2020: e.T196302A176496284. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T196302A176496284.en. Downloaded on 28 August 2021.

Pusey, B.J., Burrows, D.W., Kennard, M.J., Perna, C.N., Unmack. P.J., Allsop, Q. & Hammer, M.P. 2017. Freshwater fishes of northern Australia. Zootaxa 4253(1): 1-104

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

Pusey, B.J., Kennard, M.J. & Bird, J. 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.

Watanabe S., Miller, M.J., Aoyama, J. and Tsukamoto, K. 2011. Analysis of vertebral counts of the tropical anguillids, Anguilla megastoma, A. obscura, and A. reinhardtii, in the western South Pacific in relation to their possible population structure and phylogeny. Environmental Biology of Fishes 91: 353–360.

Quick Facts


CAAB Code:37056004

Biology:Leptocephalus larvae

Biology:Migratory - catadromous

Conservation:IUCN Data Deficient

Habitat:Freshwater to marine

Max Size:1.2 metres

Species Image Gallery

Species Maps

CAAB distribution map