Swan Galaxias, Galaxias fontanus Fulton 1978
Swan Galaxias, Galaxias fontanus. Source: Tasmanian Threatened Species Section. License: All rights reserved
A pale olive-brown galaxias becoming silvery-white below, with spots often forming darker bars and/or blotches along the side, and brownish fins.
The Swan Galaxias is the only Tasmanian galaxiid that lacks a marine larval stage, and occurs only in trout-free streams in the upper reaches of the Swan River and Macquarie River catchments.
Swan Galaxias, Galaxias fontanus Fulton 1978
More Info
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Distribution |
Restricted to the headwaters of the Swan River above Hardings Falls and isolated headwater tributaries of the Macquarie River in eastern Tasmania. As of 2019, eight extant natural populations occupied approx. 9 km of stream length. These populations are restricted to headwater areas due to the downstream presence of Brown Trout. The historic distribution of the Swan Galaxias is unknown as trout had been introduced to these catchments before the species was discovered and formally described. The Swan Galaxias is only found in the headwaters of these catchments. These areas are inaccessible to introduced Brown Trout and Redfin due to significant natural or man-made barriers. The species inhabits moderately flowing shallow spring-fed creeks, preferring areas with abundant instream and riparian vegetations in rocky pools or around woody debris. Juveniles form schools in open water. |
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Features |
Dorsal-fin rays 9-11; Anal-fin rays 11-14 (usually 12-13); Pectoral-fin rays 10-11; Vertebrae 50-53 Scales absent, body covered in smooth skin Anal-fin origin below or slightly behind dorsal-fin origin; caudal fin emarginate. |
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Size |
To around 13.5cm TL, commonly to 7cm. |
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Colour |
Overall brownish-olive with a variable pattern of darker bars and/or blotches on sides; silvery-white below. |
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Feeding |
Feeds on insects and their larvae, small crustaceans and algae and may utilise terrestrial sources of food when available (Sanger & Fulton 1991). |
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Biology |
Oviparous benthic spawners. Unlike other Tasmanain galaxiids which have a marine larval phase, the Swan Galaxias completes its entire life cycle in freshwater. Fecundity ranges from 150-500 eggs which are 2.2-2.5 mm diameter and strongly adhesive. Larvae hatch after approximately 17 days at 8mm TL. Larval stage persists for around 5 weeks before recruitment into the main population in early summer. |
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Conservation |
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Remarks |
Shoal-forming. |
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Similar Species |
Similar to Galaxias olidus, Galaxias johnstoni, Galaxias brevipinnis and Galaxias pedderensis. Differs in having the anal-fin origin below or slightly behind the dorsal-fin origin. |
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Etymology |
The specific name is from the Latin fontanus (= fountain, spring) possibly in reference to the type locality of this species. |
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Species Citation |
Galaxias fontanus Fulton, 1978, Rec. Queen Vict. Mus. 63: 2, figs 1-2, 3B. Type locality: Swan River, Tasmania. |
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Author |
Gomon, M.F. & Bray, D.J. 2020 |
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Resources |
Swan Galaxias, Galaxias fontanus Fulton 1978
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.
Crook, D.A. & Sanger, A.C. 1998. Threatened Fishes of the World: Galaxias fontanus, Fulton, 1978 (Galaxiidae). Environmental Biology of Fishes 53: 32
Freeman, R. 2019. Galaxias fontanus . The IUCN Red List of Threatened Species 2019: e.T8805A129040589. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T8805A129040589.en. Downloaded on 12 February 2020.
Fulton, W. 1978. A new species of Galaxias (Pisces : Galaxiidae) from the Swan River, Tasmania. Records of the Queen Victoria Museum, Launceston 63: 1-8 figs 1-4.
Jackson, J.E. 2002. Report on captive breeding trials conducted under the Tasmanian Galaxias Recovery Plan: Swan galaxias (Galaxias fontanus), Clarence galaxias (G. johnstoni) and saddled galaxias (G. tanycephalus). Unpublished report to Environment Australia. Inland Fisheries Service, Hobart.
Jackson, J.E. 2004. Tasmanian Galaxiidae Recovery Plan 2004-2008. Inland Fisheries Service, Hobart.
Lintermans, M. 2016. Conservation Status of Australian Fishes – 2016. Australian Society for Fish Biology Newsletter 46(2): 142-144. Available online at https://www.asfb.org.au/conservation-status-of-australian-fishes
Lintermans, M., Geyle, H.M., Beatty, S., Brown, C., Ebner, B., Freeman, R., Hammer, M.P., Humphreys, W.F., Kennard, M.J., Kern, P., Martin, K., Morgan, D., Raadik, T.A., Unmack, P.J., Wager, R., Woinarski, J.C.Z. & Garnett, S.T. 2020. Big trouble for little fish: Identifying Australian freshwater fishes in imminent risk of extinction. Pacific Conservation Biology. https://doi.org/10.1071/PC19053
McDowall, R.M. & Frankenberg, R.S. 1981. The galaxiid fishes of Australia (Pisces: Galaxiidae). Records of the Australian Museum 33: 443-605.
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.
Merrick, J.R. & Schmida, G.E. 1984. Australian Freshwater Fishes Biology and Management. Sydney : J.R. Merrick 409 pp. figs 280 col. figs.
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
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 https://doi.org/10.11646/zootaxa.3898.1.1
Threatened Species Section. 2020. Galaxias fontanus (Swan Galaxias): Species Management Profile for Tasmania's Threatened Species Link. https://www.threatenedspecieslink.tas.gov.au/Pages/Swan-Galaxias.aspx. Department of Primary Industries, Parks, Water and Environment, Tasmania. Accessed on 17/09/2020.
