Western Dwarf Galaxias, Galaxiella munda McDowall 1978
Western Dwarf Galaxias, Galaxiella munda. Source: Stephen Beatty / Freshwater Fish Group & Fish Health Unit, Murdoch University. License: All rights reserved
A very small galaxiid found creeks and streams of south-west Western Australia.
Adults are brownish-grey above with a white belly, and have several whitish blotches along the upper side, and a broad coppery-brown stripe edged in fine olive brown stripes just below the midline from behind the eye to the tail base.
Video of Western Dwarf Galaxias by the Freshwater Fish Group of Murdoch University, Western Australia.
Western Dwarf Galaxias, Galaxiella munda McDowall 1978
More Info
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Distribution |
Endemic to temperate freshwaters of south Western Australia, from the Albany district to north of Perth. The Western Dwarf Galaxias prefers swift-flowing streams in Karri forests, near submerged vegetation. The water in these streams is usually acidic (pH 3.0-6.0) and darkly tannin-stained, and the water temperature fluctuates widely with the seasons. It also occasionally occurs in ponds, swamps and roadside drains. |
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Features |
Dorsal fin 7-10 (usually 8-9); Anal fin 11-15 (usually 12-14); Pectoral fin 9-12 (usually 10-11); Pelvic fin 5-7 (usually 6); Gill rakers 16-20. Body elongate, slender, almost tubular; body depth at anus 10.5-14.3 % SL; head short, snout short and bluntly rounded; mouth small, oblique, reaching to front of eyes; jaws equal in size with no enlarged canine teeth; eye large, upper margin at head profile; gill rakers long and slender; pyloric caeca absent; compressed behind the vent; caudal peduncle longer than deep; Scales absent. Fins small and membranous; low membranous fold along caudal peduncle almost to dorsal and anal rays dorsal fin short-based; dorsal fin origin behind anal fin origin; caudal fin long, truncate to rounded; pectoral fins narrow-based, small and rounded, inserted high laterally; ventral fin very small, inserted at mid-body. |
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Size |
To 6cm SL, commonly 3.5-4.5 cm. |
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Colour |
Colour varies in relation to the water inhabited. In tannin-stained waters G. munda is dark brown on the back and sides with a silvery-white belly. May also be greenish olive dorsally with a longitudinal silvery stripe, a brownish-orange stripe (usually during the breeding season) and a narrow dark stripe with a silvery belly. |
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Feeding |
Feeds on small insects, aquatic insect larvae and microcrustaceans - usually near vegetation at the edges of streams. |
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Biology |
The Western Dwarf Galaxias has a year-long life cycle that is completed entirely in freshwater. The sexes are separate and fertilisation is external. Spawning occurs between June and October, with a peak during August and September. Females spawn several times, depositing several batches of eggs in flooded vegetation over several weeks. Adults die soon after spawning. |
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Conservation |
Also protected in Western Australia under the Wildlife Conservation Act. |
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Etymology |
Species name munda is from the Latin mundus meaning neat. |
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Species Citation |
Galaxiella munda McDowall 1978, J. R. Soc. N.Z. 8(1): 119, Figs. 1-2. Type locality: Pool in Jarrah forest, about 8 km north of Scott River, between Nanup and Augusta, 34°13'S, 115°29'E, Western Australia. |
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Author |
Gomon, M.F. & Bray, D.J. 2020 |
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Resources |
Western Dwarf Galaxias, Galaxiella munda McDowall 1978
References
Allen, G.R. 1989 Freshwater fishes of Australia. T.F.H. Publications, Inc., Neptune City, New Jersey.
Allen, G.R., Midgley, S.H. & Allen, M. 2002. Field Guide to the Freshwater Fishes of Australia. Perth : Western Australian Museum 394 pp.
Beatty, S. & Morgan, D.L. 2019. Galaxiella munda. The IUCN Red List of Threatened Species 2019: e.T8821A123377841. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T8821A123377841.en. Downloaded on 30 June 2020.
Berra, T.M. & Allen, G.R. 1989. Clarification of the difference between Galaxiella nigrostriata (Shipway, 1953) and Galaxiella munda McDowall, 1978 (Pisces: Galaxiidae) from Western Australia. Records of the Western Australian Museum 14: 293–297.
Brown, T.R., Todd, C.R., Hale, R., Swearer, S.E. & Coleman, R.A. 2020. Testing the adaptive advantage of a threatened species over an invasive species using a stochastic population model. Journal of Environmental Management 264, https://doi.org/10.1016/j.jenvman.2020.110524
Coleman, R.A., Hoffman, A.A. & Raadik, T.A. 2015. A review of Galaxiella pusilla (Mack) (Teleostei: Galaxiidae) in south-eastern Australia with a description of a new species. Zootaxa 4021(2): 243-281.
Gill, H.S. & Neira, F.J. 1998 Galaxiidae (Galaxiinae): southern galaxias. pp. 70-77 in Neira, F.J., Miskiewicz, A.G. & Trnski, T. Larvae of temperate Australian fishes: laboratory guide for larval fish identification. Nedlands, Western Australia : University of Western Australia press 474 pp.
McDowall, R.M. 1978. A new genus and species of galaxiid fish from Australia (Salmoniformes: Galaxiidae). Journal of the Royal Society of New Zealand 8(1): 115-124.
McDowall, R.M. & Frankenburg, R.S. 1981. The galaxiid fishes of Australia. Records of the Australian Museum 33: 443–605.
McDowall, R.M. & Waters, J.M. 2004. Phylogenetic relationships in a small group of diminutive galaxiid fishes and the evolution of sexual dimorphism. Journal of the Royal Society of New Zealand 34(1): 23-57.
Merrick, J.R. & G.E. Schmida 1984 Australian freshwater fishes: biology and management. Griffin Press Ltd., South Australia. 409 p.
Morgan, D., Gill, H. & Potter, I. (1996). The distribution of freshwater fish in the southwestern corner of Australia. Report to Water and Rivers Commission. Waters and Rivers Commission, Perth, Western Australia.
Morgan, D.L., Gill, H.S. & Potter, I.C. (1998). Distribution, identification and biology of freshwater fishes in south-western Australia. Records of the Western Australian Museum. Supplement No 56, Perth, Western Australia.
Paxton, J.R., D.F. Hoese, G.R. Allen & J.E. Hanley 1989 Zoological Catalogue of Australia. Volume 7. Pisces. Petromyzontidae to Carangidae. Australian Government Publishing Service, Canberra. Zoological Catalogue of Australia. Volume 7. v. 7: i-xii + 1-665.
Pen, L.J., Gill, H.S., Humphries, P. & Potter, I.C. 1993. Biology of the black-stripe minnow Galaxiella nigrostriata, including comparisons with the other two Galaxiella species. Journal of Fish Biology 43: 847–863. http://dx.doi.org/10.1111/j.1095-8649.1993.tb01160.x
Unmack PJ, Bagley JC, Adams M, Hammer MP, Johnson JB (2012) Molecular phylogeny and phylogeography of the Australian freshwater fish genus Galaxiella, with an emphasis on Dwarf Galaxias (G. pusilla). PLoS ONE 7(6): e38433. doi:10.1371/journal.pone.0038433
Wager, R. 1996. Galaxiella munda. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 18 May 2011.
