Swan Galaxias, Galaxias fontanus Fulton 1978


Swan Galaxias, Galaxias fontanus. Source: Gerald R. Allen. License: All rights reserved

Summary:

A pale olive-brown galaxias becoming silvery-white below, with spots on the sides often forming darker bars and/or blotches, and brownish fins.

The Swan Galaxias is the only Tasmanian galaxiid that lives its entire life in freshwater and does not have a marine larval stage. It occurs only in trout-free streams in the upper reaches of the Swan River and Macquarie River catchments. Natural populations are very small and highly fragmented, and have declined dramatically since 2004.


Cite this page as:
Gomon, M.F. & Bray, D.J. 2018, Galaxias fontanus in Fishes of Australia, accessed 18 Oct 2018, http://fishesofaustralia.net.au/home/species/3673

Swan Galaxias, Galaxias fontanus Fulton 1978

More Info


Distribution

Known only from the Swan River and Macquarie River catchments in eastern Tasmania. A number of successfully translocated populations also occur in other areas. 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.

Features

Dorsal-fin rays 9-11; Anal-fin rays 11-14 (usually 12-13); Pectoral-fin rays 10-11; Vertebrae 50-53
Body elongate, tubular; head flattened, eyes at upper head profile, interorbital broad and flat; depth at vent 6.1-7.6 in SL; enlarged lateral canine teeth in jaws

Scales absent, body covered in smooth skin

Anal-fin origin below or slightly behind dorsal-fin origin; caudal fin emarginate.

Size

To around 13.5cm TL, commonly to 7cm.

Colour

Overall brownish-olive with a variable pattern of darker bars and/or blotches on sides; silvery-white below.

Feeding

Feeds on insects and their larvae, small crustaceans and algae and may utilise terrestrial sources of food when available (Sanger & Fulton 1991).

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.

Conservation

  • Swan Galaxias are threatened by invasive Brown Trout, along with the impacts of climate change (both drought and floods). 
  • Remarks

    Shoal-forming.

    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.

    Species Citation

    Galaxias fontanus Fulton, 1978, Rec. Queen Vict. Mus. 63: 2, figs 1-2, 3B. Type locality: Swan River, Tasmania.

    Author

    Gomon, M.F. & Bray, D.J. 2018

    Resources

    Australian Faunal Directory

    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

    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.

    McDowall, R.M. (ed.) 1996. Freshwater Fishes of South-eastern Australia. Sydney : Reed Books 247 pp.

    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

    Sanger, A.C. 1993. The Swan Galaxias Recovery Plan: Management Phase. Inland Fisheries Commission, Tasmania.

    Threatened Species Unit. 1998. Listing Statement Swan Galaxias Galaxias fontanus. Parks and Wildlife Service, Tasmania, 3 pp.

    Threatened Species Section. 2006. Recovery Plan: Tasmanian Galaxiidae 2006-2010. Department of Primary Industries, Water, Hobart. 85 pp.

    Wager, R. 1996. Galaxias fontanus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 21 May 2013.

    Quick Facts


    CAAB Code:37102004

    Behaviour:ASFB & IUCN Critically Endangered; EPBC & TAS Endangered

    Behaviour:Schooling species

    Habitat:Freshwater creeks, streams

    Max Size:13.5 cm TL

    Native:Endemic

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