Australian Smelt, Retropinna semoni (Weber 1895)
Australian Smelt, Retropinna semoni. Source: Gunther Schmida / http://www.guntherschmida.com.au. License: CC BY Attribution-Noncommercial-ShareAlike
A small, slender freshwater fish with a small dorsal fin set far back on the body, a small adipose fin, a forked tail and large eyes.
Australian Smelt are silvery to almost transparent, or slightly olive-brown above, silvery on the sides with a silvery-white belly. Some individuals in the northern parts of its range may have orange markings and fins.
Genetic work (Hammer et al. 2007) indicates that Retropinna semoni belongs to a species complex, and the Australian Smelt may not be as widespread and abundant as previously thought. As a result, the information presented here may refer to more than one closely-related species.
Video of Australian Smelt in the Cann River, East Gippsland, Victoria.
Australian Smelt, Retropinna semoni (Weber 1895)
More Info
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Distribution |
Endemic to coastal drainages of south-eastern Australia, from the Fitzroy River, southern QLD (23°25’S) to the Murray River, SA (138°50’E), from the south-east of the main Murray Darling / Culgoa / Condamine drainage towards the main eastern divide, and from Darr River / Thompson River/Cooper Creek drainage flowing south-west to Lake Eyre. A schooling species found in slow- flowing and still fresh water habitats such as lakes, dams and billabongs, shoaling near the surface or around the cover of aquatic plants and woody debris; also inhabits swamps, backwaters, brackish estuaries and inland salt lakes. |
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Features |
Meristic features: Dorsal-fin rays 7-12; Anal-fin rays 12-21; Caudal-fin rays 18; Pectoral-fin rays 8-12; Pelvic-fin rays 7; Vertebrae 45 to 53 Body elongate, compressed, slender; dorsal and ventral profiles even and gradually arched; head of moderate size (19-29% SL); snout bluntly pointed; eyes large (25-36% HL); mouth terminal, of moderate size, reaching well below eyes, slightly oblique; jaw teeth fang-like, spaced in a single row; vomer, tongue, palatine and mesopterygoid bones with rows of fine teeth; gillrakers on first arch 45-55; lateral line absent; caudal peduncle long and slender; ventral keel often present, extending from behind pelvic fin to vent. Head naked, body scales cycloid, thin and delicate; scales of moderate size, 50-70 in lateral series. A single high, short-based dorsal fin positioned above the anus; small adipose fin behind dorsal; anal fin much longer than dorsal, high anteriorly, outer margin concave, origin below front of dorsal fin; caudal fin forked, lobes rounded; pectoral fins small, elongate, rounded, low on side behind head; ventral fins abdominal. Males have larger pectoral and pelvic fins, and larger nuptial tubercles on the body and head. |
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Size |
To 10 cm, commonly to 7cm. |
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Colour |
Silvery, somewhat olive above with a purplish sheen along sides, belly whitish, fins largely colourless with some dark colouring at bases. Some individuals appear orange. |
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Feeding |
Carnivore - feeds mostly on insects and microcrustaceans. |
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Biology |
Individuals mature in their first year and spawn between July and March. Demersal eggs are laid amongst aquatic vegetation. Fecundity may be low, although numbers of 100-1000 eggs have been reported depending on the size of the female. The eggs are spherical, transparent, strongly adhesive and demersal, 0.8mm when laid and expand to about 1mm when water hardened. Larvae hatch in around 10 days at around 4.6 mm TL. Yolk sac is completely absorbed at 2 days and fin folds are complete at 5 days. |
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Conservation |
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Remarks |
Primarily a freshwater species, although it is also inhabits brackish estuaries and inland salt lakes. Often congregates in schools of thousands, and has a distinct cucumber smell when freshly caught. |
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Species Citation |
Prototroctes semoni Weber, 1895, Zool. Stud. 5(2): 257-276. Type locality: Burnett River, QLD. |
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Author |
Martin F. Gomon & Dianne J. Bray |
Australian Smelt, Retropinna semoni (Weber 1895)
References
Allen, G.R., Midgley, S.H. & Allen, M. 2002. Field Guide to the Freshwater Fishes of Australia. Perth : Western Australian Museum 394 pp.
Cadwallader, P.L. & Backhouse, G.N. 1983. A Guide to the Freshwater Fish of Victoria. Melbourne : F.D. Atkinson Government Printer 249 pp. figs.
Grant, E.M. 2002. Guide to Fishes. Redcliffe : EM Grant Pty Ltd 880 pp.
Hammer, M.P., M. Adams, P.J. Unmack & K. Walker. 2007. A rethink on Retropinna: conservation implications of new taxa and significant genetic sub-structure in Australian smelts (Pisces : Retropinnidae). Marine and Freshwater Research 58(4): 327–341 http://dx.doi.org/10.1071/MF05258
Hoese, D.F., Paxton, J.R. & Gates, J.E. 2006. Retropinnidae. pp. 396-398 in Beesley, P.L. & Wells, A. (eds). Zoological Catalogue of Australia. Volume 35 Australia : ABRS & CSIRO Publishing Parts 1-3 2178 pp.
Humphries, P., Serafini, L.G. & King, A.J. 2002. River regulation and fish larvae: variation through space and time. Freshwater Biology 47: 1307–1331.
Lake, J.S. 1978. Australian Freshwater Fishes. Melbourne : Thomas Nelson 160 pp. 140 figs.
Leggett, R. & Merrick, J.R. 1987. Australian Native Fishes for Aquariums. Artarmon : J.R. Merrick Publications 241 pp. 142 figs.
Leigh, S.J. 2002. Aspects of the Life-History and Population Biology of the Australian Smelt, Retropinna semoni (Weber 1895) (Salmoniformes: Retropinnidae) for a Lower Murray River Population. Unpubl. B Sc (Hons) thesis, University of Adelaide.
Mallen-Cooper, M. 1994. How high can a fish jump? New Scientist 142 (1921): 32–37.
McDowall, R.M. 1979. Fishes of the family Retropinnidae (Pisces : Salmoniformes): A taxonomic revision and synopsis. Journal of the Royal Society of New Zealand 9(1): 85-121 figs 1-11
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. (ed.) 1996. Freshwater Fishes of South-eastern Australia. Sydney : Reed Books 247 pp.
Merrick, J.R. & Schmida, G.E. 1984. Australian Freshwater Fishes Biology and Management. Sydney : J.R. Merrick 409 pp. figs 280 col. figs.
Milton, D.A. & Arthington, A.H. 1985. Reproductive strategy and growth of the Australian smelt, Retropinna semoni (Weber) (Pisces: Retropinnidae), and the olive perchlet, Ambassis nigripinnis (De Vis) (Pisces: Ambassidae), in Brisbane, south-eastern Queensland. Australian Journal of Marine and Freshwater Research 36(3): 329–341.
Moffat, D. & Voller, J. 2002. Fish and Fish Habitat of the Queensland Murray-Darling Basin. Department of Primary Industries, Queensland.
Pusey, B.J., Kennard, M.J. & Arthington, A.H. 2004. Freshwater Fishes of North-Eastern Australia. CSIRO Publishing, Collingwood, Victoria.
Raadik, T.A. 1992. Distribution of freshwater fishes in east Gippsland, Victoria, 1967–1991. Proceedings of the Royal Society of Victoria 104: 1-22
Stokell, G. 1941. A revision of the genus Retropinna. Records of the Canterbury Museum 4(7): 361-372 fig. 1 pls 55-57
Wager, R. & Unmack, P.J. 2000. Fishes of the Lake Eyre Catchment of Central Australia. Brisbane : Department of Primary Industries and Queensland Fisheries Service 88 pp.
Weber, M. 1895. Fische von Ambon, Java, Thursday Island dem Burnett-Fluss und von der Süd-Küste von Neu-Guinea. Zoological Studies 5(2): 257-276 1 fig.
Wedderburn, S. & Hammer, M. 2003. The Lower Lakes Fish Inventory: Distribution and Conservation of Freshwater Fishes of the Ramsar Convention Wetland at the Terminus of the Murray-Darling Basin, South Australia. Native Fish Australia (SA) Inc., Adelaide. 38 pp.
