Obscure Galaxias, Galaxias oliros Raadik 2014

Summary:

An olive to greyish-brown galaxias (often overlain with a golden iridescence) becoming cream to white or silvery below, with dark brown to greyish-brown blotches, flecks and patches, many forming irregular vertical bars along the side, and often a large turquoise or gold patch on the gill cover. The dorsal fin originates slightly before the anal-fin origin.

Obscure Galaxias (Galaxias oliros) in the Grampians, Victoria.

Cite this page as:

Bray, D.J. 2020, Galaxias oliros in Fishes of Australia, accessed 21 Apr 2024, https://fishesofaustralia.net.au/home/species/5129

Obscure Galaxias, Galaxias oliros Raadik 2014

More Info

Distribution	Widespread in the Murray River system and tributaries, and also found south of the Great Dividing Range in western Victoria, at elevations of 0–600 m asl. Specifically, found in the Murray River from the Upper Murray Basin in southern New South Wales and northern Victoria westward, including all VIC tributaries and the endorheic Wimmera River system, in several tributaries of the Lower Murray draining the eastern Mount Lofty Ranges (South Australia), and in coastal Victoria in the endorheic Corangamite Basin, and westward from, and including the Hopkins River basin to Mosquito Creek in the Bool Lagoon drainage in SA. Found very close to the coast in the Merri River and the Darlot/Fitzroy River systems in coastal western VIC, and appears to be absent from the Murray River main channel downstream from about Barmah to Mannum. Known from a single catchment in the SA Gulf Drainage Division (Hindmarsh River) (Raadik 2014).
Features	The Obscure Galaxias has the following combination of characters: trunk usually laterally compressed posteriorly from about above the pelvic fin base; caudal fin emarginate to weakly forked; usually 12 segmented rays in anal fin (range 9–14), and always more than in the dorsal fin, which usually has about 9 segmented rays; length of anal fin base long (9.8–14.1 % SL) and that of dorsal fin short (7.4–10.8 % SL) and anal fin long (14.3–19.7 % SL); caudal peduncle somewhat shallow (6.5–9.0 % SL); pelvic fins moderately large, about 91 % of length of pectoral fins; lateral profile of head slightly to moderately wedge-shaped and snout rounded; inter-orbital wide (36.0–46.4 % HL) and eye moderately large (16.4–23.9 % HL); nostrils of moderate length, usually not visible from ventral view; anterior tip of upper lip level with about 0.6 ED above ventral margin of eye; raised lamellae usually absent from ventral surface of rays of paired fins, very occasionally present but weakly developed; anal fin origin usually under 0.47 distance posteriorly along dorsal fin base, often much less; usually a single, short (1.2 % SL) pyloric caecum though often absent; gill rakers variable, of moderate length to long and stout to thin; and, distinct black bars along lateral line usually absent, though occasionally some individuals with darker mid-lateral dark brownish blotches between the pectoral and pelvic fin bases, or a single, to a series of, very narrow and short faint brown to greyish dark brown mid-lateral bars anteriorly behind the pectoral fin base.
Colour	Body predominantly olive to grey-brown on back and sides, extending over head and snout, becoming cream to white or silvery below lateral line, belly usually silvery. Overlain by small to moderate sized dark brown to grey brown, irregular shaped blotches, flecks and patches, many coalescing to form irregularly shaped vertical bands; blotches and patches more densely distributed over dorsal surface of trunk and on to nape, absent from head and snout. Gill cover often with a large turquoise or gold patch (Raadik 2014).
Etymology	The specific name oliros is derived from a combination of the first three letters of the species names of Galaxias olidus and Galaxias rostratus. It was first used as a field code for what appeared to be a distinct morphological form intermediate between, and sharing morphological characteristics with, both taxa, particularly juvenile to young adult stages.
Species Citation	Galaxias oliros Raadik 2014, Zootaxa 3898(1): 111, Figs. 25-26. Type locality: Avoca River, Mount Lonarch Road, south-south-east of Mount Lonarch, Victoria, 37° 16' 47”S 143° 21' 40”E,
Author	Bray, D.J. 2020
Resources	Atlas of Living Australia Australian Faunal Directory Catalog of Fishes

Obscure Galaxias, Galaxias oliros Raadik 2014

References

Adams, M., Raadik, T.A., Burridge, C.P. & Georges, A. 2014. Global biodiversity assessment and hyper-cryptic species complexes: more than one species of elephant in the room. Systematic Biology 63(4): 518–533. (as taxon 'OR')

Allen, G.R., Midgley, S.H. & Allen, M. 2002. Field Guide to the Freshwater Fishes of Australia. Perth : Western Australian Museum 394 pp. (as Galaxias olidus - in part)

Cook, B.D., Kennard, M.J., Adams, M., et al. 2019. Hydrographic correlates of within‐river distribution and population genetic structure in two widespread species of mountain galaxias (Teleostei, Galaxiidae) in southern Australia. Freshwater Biology 64: 506-519. https://doi.org/10.1111/fwb.13238

Hammer, M.P., Adams, M. & Foster, R. 2012. Update to the catalogue of South Australian freshwater fishes (Petromyzontida & Actinopterygii). Zootaxa 3593: 59–74 (p. 63, as Galaxias sp.)

Kuiter, R.H. 2013. Pictorial Guide to Victoria's Freshwater Fishes. Seaford, Victoria : Aquatic Photographics 178 pp. (as Galaxias sp. 1, Galaxias sp. 4 in part, Galaxias sp. 10, Galaxias sp. 11)

McDowall, R.M. & Fulton, W. 1996. Chapter 10. Family Galaxiidae — galaxiids. pp. 52-77 in McDowall, R.M. (ed.) Freshwater Fishes of South-eastern Australia. Sydney : Reed Books 247 pp. (as Galaxias olidus - in part)

Raadik, T.A. 2011. Systematic revision of the Mountain Galaxias, Galaxias olidus Günther, 1866 species complex (Teleostei: Galaxiidae) in eastern Australia. Ph.D thesis, University of Canberra. pp. i-xxiii, 1-493 (as Galaxias ‘oliros’)

Raadik, T.A. 2014. Fifteen from one: a revision of the Galaxias olidus Günther, 1866 complex (Teleostei, Galaxiidae) in south-eastern Australia recognises three previously described taxa and describes 12 new species. Zootaxa 3898(1): 1-198

Raadik, T. 2019. Galaxias oliros. The IUCN Red List of Threatened Species 2019: e.T122902581A123382146. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T122902581A123382146.en. Downloaded on 06 February 2020.