Australian Grayling, Prototroctes maraena Günther 1864


Other Names: Cucumber Fish, Cucumber Herring, Cucumber Mullet, Cucumberfish, Cucumber-fish, Grayling, Yarra Herring

Australian Grayling, Prototroctes maraena. Source: Tarmo Raadik. License: all rights reserved

Summary:
A small to medium-sized silvery fishes with a small adipose fin on the rear of the back, a keel along the belly, no lateral line and a horny sheath around the lower jaw. 
Adult Australian Grayling inhabit freshwater rivers and streams. In the autumn months, they undertake large spawning migrations to the lower reaches of rivers. The newly hatched larvae are swept out to sea before they migrate back to estuaries after about 6 months. The species has a distinct cucumbery smell.

Cite this page as:

Martin F. Gomon & Dianne J. Bray, 2011, Australian Grayling, Prototroctes maraena, in Fishes of Australia, accessed 25 Apr 2014, http://www.fishesofaustralia.net.au/home/species/3634

Australian Grayling, Prototroctes maraena Günther 1864

More Info


Distribution

Endemic to coastal drainages of southeastern Australia, from the Shoalhaven River, New South Wales, westward to the eastern part of South Australia, and widespread in coastal Tasmania, including King Island in Bass Strait. Historic records show that Australian Grayling were once found as far north as the Grose River near Sydney.

Adults prefer moderate to fast-flowing water in rivers and streams, and are usually found in cool clear waters sometimes to altitudes above 1,000 m. They often occur in pools with gravelly substrates, and often form large schools, especially before spawning.

The Australian Grayling is a diadromous species, and migrates between rivers and coastal waters during its life cycle. The species therefore relies on having free access to a range of freshwater, estuarine and marine coastal habitats.

Features

Mersitic features: Dorsal fin 9-13; Anal fin 16-20; Pectoral fin 12-14; Pelvic fin 6; Vertebrae 62-65

Body long and slender, compressed; head small, conical with bluntly rounded snout; eye of moderate size; mouth slightly oblique, small; gape extending back to beneath eye; lower jaw shorter than upper jaw, tapering to a fine point; gill rakers on first arch 20-26; teeth in upper jaw blunt in a comb-like row; weak abdominal keel present in front of anus. Scales thin, cycloid of moderate size, 68-86 in lateral series; lateral line absent. Dorsal fin in about middle of back, behind ventral fin; small adipose fin present behind dorsal; ventral fins on middle of belly, small, rounded; caudal fin forked; anal fin beneath space between dorsal and adipose fin; pectoral fins well forward, low, small, triangular.

Size

Maximum size to 33 cm TL but commonly to 17-19 cm TL.

Colour

Dusky brown to greenish-brown above, greenish to bronze midlaterally and silvery-white to yellowish below. Sometimes has a steely-blue mid-lateral band and dark spot on the caudal fin base. Fins greyish-white.

Feeding

Australian Grayling are omnivores, feeding mainly on algae, but also some insects and microcrustaceans. They have highly specialised dentition and a long specialised gut to help digest algae.

Biology

The Australian Grayling is an amphidromous species. Adults in habit freshwater rivers and streams, and undertake spawning migrations to the lower reaches of rivers between February and May - usually coinciding with increased river flows. The species is highly fecund, and females spawn on average 47000 eggs. 


The eggs are demersal and sink to the bottom downstream of where they are spawned. Larvae hatch at 6-7 mm TL after 10-20 days, and are carried downstream into estuaries and out to sea. They spend about 6 months at sea before rmigrating back to freshwater in the spring as 'whitebait' .

Fisheries

Once popular with recreational anglers, but now protected under the EPBC Act and protected in New South Wales. Heavy penalties apply for taking or possessing them.

Conservation

IUCN Red List: Near threatened.

EPBC Act 1999: Vulnerable

NSW Fisheries Management Act 1994: Protected

VIC Flora & Fauna Guarantee Act 1988: Protected. Taking or attempting to take, including catch and release, is prohibited.

Populations of Australian Grayling have declined due to a range of factors including habitat degradation, barriers to movement, competition with introduced species, including Eastern Gambusia (Gambusia holbrooki) and trout species, climae change and fishing. The species is now the focus of a number of conservation measures.

Remarks

Often form aggregations below barriers to upstream movement such as weirs and waterfalls. Exudes a cucumber-like smell when freshly caught.

Species Citation

Prototroctes maraena Günther 1864, Cat. fishes Brit. Mus.5: 382. Type locality: Southern Australia.

Author

Martin F. Gomon & Dianne J. Bray

Australian Grayling, Prototroctes maraena Günther 1864

References


Allen, G.R. 1989. Freshwater Fishes of Australia. Neptune, New Jersey : T.F.H. Publications 240 pp., 63 pls

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

Bacher, G.J. & O'Brien, T.A. 1989. Salinity tolerance of the eggs and larvae of the Australian grayling Prototroctes maraena Gunther (Salmoniformes : Prototroctidae). Aust. J. Mar. Freshw. Res. 40: 227-30.

Backhouse, G., Jackson, J. & O’Connor, J. (2008). Background and implementation information for the Australian grayling Prototroctes maraena national recovery plan. Department of Sustainability and Environment, Melbourne. 

Backhouse, G., Jackson, J. & O’Connor, J. 2008. National recovery plan for the Australian grayling Prototroctes maraena. Department of Sustainability and Environment, Melbourne. 

Berra, T.M. 1982. The life history of the Australian grayling, Prototroctes maraena Gunther (Salmoniformes : Prototroctidae), in the Tambo River, Victoria. Copeia 1982 (4): 795-804.

Berra, T.M. 1984. Reproductive anatomy of the Australian grayling, Prototroctes maraena Gunther. J. Fish Biol. 25: 241-251.

Berra, T. & Cadwallader, P. 1983. Age and growth of Australian grayling, Prototroctes maraena Günther (Salmoniformes: Prototroctidae), in the Tambo River, Victoria. Marine and Freshwater Research 34: 451–460. 

Bishop, K.A. & Bell, J.D. 1978. Aspects of the biology of the Australian grayling Prototroctes maraena Gunther (Pisces : Prototroctidae). Aust. J. Mar. Freshw. Res. 29: 743-761.

Cadwallader, P.L. & Backhouse, G.N. 1983. A Guide to the Freshwater Fish of Victoria. Melbourne : F.D. Atkinson Government Printer 249 pp. figs

Crook, D.A., Macdonald, J.I., O’Connor, J.P. & Barry, B. 2006. Use of otolith chemistry to examine patterns of diadromy in the threatened Australian grayling (Prototroctes maraena). Journal of Fish Biology 69: 1330–1344. 

Grant, E.M. 2002. Guide to Fishes. Redcliffe : EM Grant Pty Ltd 880 pp.

Günther, A. 1864. Catalogue of the Fishes of the British Museum. Catalogue of the Physostomi, containing the families Siluridae, Characinidae, Haplochitonidae, Sternoptychidae, Scopelidae, Stomiatidae in the collection of the British Museum. London : British Museum Vol. 5 455 pp.

Hall, D.N. & Harrington, D.J. 1989. Studies on the spawning and early life history of Australian grayling, Prototroctes maraena Günther, in the Barwon River, Victoria. Arthur Rylah Institute for Environmental Research Technical Report Series No. 84. Department of Conservation, Forests and Land, Melbourne. 

Jackson, P. 1976. A note on the food of the Australian grayling, Prototroctes maraena Günther (Galaxoidei: Prototroctidae). Australian Journal of Marine and Freshwater Research 27(3): 525-528.

Jackson, P. & Koehn, J. 1988. A review of biological information, distribution and status of the Australian grayling (Prototroctes maraena) Günther in Victoria. Arthur Rylah Institute for Environmental Research Technical Report Series No. 52. Conservation Forests and Lands, Melbourne.

Jenkins, A., Kullander, F.F. & Tan, H.H. 2009. Prototroctes maraena. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 06 February 2012.

Koster, W.M., D.R. Dawson & D.A. Crook. 2013. Downstream spawning migration by the amphidromous Australian grayling (Prototroctes maraena) in a coastal river in south-eastern Australia. Marine and Freshwater Research 64(1): 31-41 http://dx.doi.org/10.1071/MF12196

McDowall, R.M. 1988 Diadromy in fishes: migrations between freshwater and marine environments. Croom Helm, London.

McDowall, R.M. 1994. Families Retropinnidae, Prototroctidae, Galaxiidae. pp. 232-239 figs 207-212 in Gomon, M.F., Glover, C.J.M. & Kuiter, R.H (eds). The Fishes of Australia's South Coast. Adelaide : State Printer 992 pp. 810 figs

McDowall, R.M. 1996. Family Protoroctidae southern graylings, pp 96-98. In: McDowall, R.M. (ed.) 1996. Freshwater Fishes of South-eastern Australia. Sydney : Reed Books 247 pp.

McDowall, R.M. 1997. The evolution of diadromy in fishes (revisited) and its place in phylogenetic analysis. Rev. Fish Biol. Fish 7: 443–462.

McDowall, R.M. 2006. Crying wolf, crying foul, or crying shame: alien salmonids and a biodiversity crisis in the southern cool-temperate galaxioid fishes? Reviews in Fish Biology and Fisheries 16: 233 - 422.

McDowall, R.M. 2007. On amphidromy, a distinct form of diadromy in aquatic organisms. Fish and Fisheries 8: 1–13. 

McDowall, R.M. 2010. Why be amphidromous: expatrial dispersal and the place of source and sink population dynamics? Reviews in Fish Biology and Fisheries 20: 87–100.

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

Munro, I.S.R. 1961. Handbook of Australian fishes. Nos 1–42. Australian Fisheries Newsletter 15–17, 19, 20: 1-172 [published as separates 1956–1961] [29] (205)

O’Connor, J. P., and Mahoney, J. C. 2004. Observations of ovarian involution in the Australian grayling (Prototroctes maraena). Ecology Freshwater Fish 13: 70–73.

Parkinson, D., Philippart, J.C. & Baras, E. 1999. A preliminary investigation of spawning migrations of grayling in a small stream as determined by radio-tracking. Journal of Fish Biology 55: 172–182.

Raadik, T.A. 1992. Distribution of freshwater fishes in east Gippsland, Victoria, 1967–1991. Proceedings of the Royal Society of Victoria 104: 1-22.

Schmidt, D.J., Crook, D.A., O’Connor, J.P. & Hughes, J.M. 2011. Genetic analysis of threatened Australian grayling Prototroctes maraena suggests recruitment to coastal rivers from an unstructured marine source population. Journal of Fish Biology 78: 98–111. 

Stead, D. 1903. The Australian grayling – Prototroctes maraena, Günther. Fisheries of New South Wales, report of Commissioners for year 1902. Report No. 18.

Quick Facts


CAAB Code:37103001

Biology:Migratory with marine larvae

Conservation:EPBC Act Vulnerable; IUCN Near Threatened

Feeding:Omnivore

Habitat:Freshwater, estuarine, marine

Max Size:33 cm TL

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