Salamanderfish, Lepidogalaxias salamandroides Mees 1961


Other Names: Dwarf Pencilfish, Long-finned Galaxias, Mud Minnow, Scaled Galaxias

A male Salamanderfish, Lepidogalaxias salamandroides. Source: Gerald R. Allen / Western Australian Museum. License: All rights reserved

Summary:

The remarkable Salamanderfish is a small elongate freshwater fish found only in southwestern Australia. 

Salamanderfish live in small semi-permanent (ephemeral) pools and streams and are uniquely adapted to survive the desiccation of their habitat. When pools dry out, they burrow into the damp bottom sand which remains moistened by ground water. Here they aestivate, breathing through their skin and being sustained by the fat reserves of their body. They even store the urea they produce until they emerge when the rains arrive.

YouTube video of Salamanderfish by the Freshwater Fish Group of Murdoch University, Western Australia

YouTube clip of a Salamanderfish by Heiko Bleher.


Cite this page as:
Bray, D.J. 2017, Lepidogalaxias salamandroides in Fishes of Australia, accessed 21 Jan 2018, http://fishesofaustralia.net.au/home/species/3918

Salamanderfish, Lepidogalaxias salamandroides Mees 1961

More Info


Distribution

Endemic to temperate freshwaters of south-west Western Australia, and known only from heathland peat flats between the Blackwood and Kent Rivers - and area that experiences winter rains and summer droughts.

Salamanderfish inhabit small semi-permanent heathland pools and streams that are usually acidic (pH ~3-6) and high in tannins, with a marked variation in daily water temperature (16-34 °C). By late summer, most pools have evaporated and usually remain dry until late autumn when the rains return.

To survive these times of drought,  Salamanderfish 'aestivate' by burrowing into the sandy bottom which remains moistened by ground water. Even during summer, they will remerge if rains arrive, only to burrow back down when the pools again dry up.

Features

Meristic features: Dorsal fin 5-7; anal fin 11-12; Pectoral fin 10-12; Pelvic fin 4; Caudal fin 12-14.

Body very slender, elongate, scaled; head blunt; dorsal fin tall, short-based, situated above the anal fin posterior to the pelvic fins; no adipose fin; pelvic fins abdominal; anal fin of male with a scaly sheath and modified rays for internal fertilisation; caudal fin rounded or lanceolate. All fin rays are finely segmented and unbranched except for one or two anal-fin rays.

Size

To 67 mm standard length, 74 mm toal length.

Colour

Back and sides greenish-brown with black blotches, silvery-white below, fin membranes clear. The blotches on males form a dark mid-lateral stripe that extends through the eye.

Feeding

Carnivore - feeds mainly on aquatic insect larvae.

Biology

The sexes are separate and fertilisation is internal. Salamanderfish spawn during winter months when water levels are highest in the pools and streams in shich they live. Males have a modified anal fin for copulation, and produce a sticky mucous to join to females.

Females produce between 100-400 eggs with a diameter of 1.1-1.3 mm. The larvae and juveniles grow rapidly in readiness for summer drought. Larvae hatch at 5.5 mm and immediately become bottom-dwellers. At hatching, larvae are elongate, and have a functional mouth, well-developed and pigmented eyes, and a moderate yolksac, which appears to be partially enclosed by a thin layer of muscles and well-developed pelvic fins. Notochord flexion starts at about 7.5 mm and is complete by approximately 11.5 mm (Gill & Morgan 1999).

Females are larger than males and  individuals may reach 5 years of age.

Conservation

IUCN Red List : Near Threatened (Lower Risk)

Etymology

Lepidogalaxias is from the Greek lepis, -idos, meaning scale and galaxias meaning milk or milky. The species is named salamandroides due to its resemblance to a salamander.

Author

Bray, D.J. 2017

Salamanderfish, Lepidogalaxias salamandroides Mees 1961

References


Allen, G.R. & T.M. Berra. 1989. Life history aspects of the West Australian salamanderfish, Lepidogalaxias salamandroides Mees. Rec. West. Aust. Mus. 14: 253-267.

Allen, G.R., S.H. Midgley & M. Allen. 2002. Field guide to the freshwater fishes of Australia. Western Australian Museum, Perth, Western Australia. 394 p.

Allen, G.R., N.J. Cross & D.F. Hoese 2006. Lepidogalaxiinae. pp. 400-401 in Beesley, P.L. & Wells, A. (eds). Zoological Catalogue of Australia. Volume 35 Australia : ABRS & CSIRO Publishing Parts 1-3, 2178 pp.

Berra, Tim M. 1995. Lepidogalaxiidae. Lepidogalaxias salamandroides. The Salamanderfish of Western Australia. Version 01 January 1995. http://tolweb.org/Lepidogalaxias_salamandroides/15164/1995.01.01in The Tree of Life Web Project, http://tolweb.org/

Berra, T.M. & G.R. Allen. 1989. Burrowing, emergence, behavior, and functional morphology of the Australian salamanderfish, Lepidogalaxias salamandroides. Fisheries 14(5): 2-10.

Berra, T.M. & G.R. Allen. 1991. Population structure and development of Lepidogalaxias salamandroides (Pisces: Salmoniformes) from Western Australia. Copeia 1991: 845- 850.

Berra, T.M. & G.R. Allen. 1995. Inability of salamanderfish, Lepidogalaxias salamandroides, to tolerate hypoxic water. Rec. West. Aust. Mus. 17: 117.

Berra, T.M. & B.J. Pusey 1997. Threatened fishes of the world: Lepidogalaxias salamandroides Mees, 1961 (Lepidogalaxiidae). Environmental Biology of Fishes 50: 201-202.

Berra, T.M., D.M. Sever, & G.R. Allen. 1989. Gross and histological morphology of the swimbladder and lack of accessory respiratory structures in Lepidogalaxias salamandroides, an aestivating fish from Western Australia. Copeia 1989: 850-856.

Christensen, P. 1982. The distribution of Lepidogalaxias salamandroides and other small fresh-water fishes in the lower south-west of Western Australia. J. Roy. Soc. West. Aust. 65: 131-141.

Collin, H.B. & Collin, S.P. (1996) Fine structure of the cornea in the freshwater salamanderfish, Lepidogalaxias salamandroides. Cornea 15: 414-426.

Collin, S.P. & Collin, H.B. (1998) Retinal and lenticular ultrastructure in the aestivating salamanderfish, Lepidogalaxias salamandroides (Galaxiidae, Teleostei) with special reference to a new type of photoreceptor mosaic. Histol. Histopathol. 13: 1037-1048.

Frankenberg, R.S. 1969. Studies on the evolution of galaxiid fishes with particular reference to the Australian fauna. Ph.D. Thesis, University of Melbourne, Melbourne, Australia. pp. 185

Gill, H.S. & Morgan, D.S. (1999) Larval development of the salamanderfish, Lepidogalaxias salamandroides Mees (Lepidogalaxiidae). Copeia 1999(1): 219-224.

Gill, H.S. & Morgan, D.S. (2003) Ontogenetic changes in the diet of the black-stripe minnow Galaxiella nigrostriata (Shipway, 1953) (Galaxiidae) and the salamanderfish Lepidogalaxias salamandroides (Mees, 1961) (Lepidogalaxiidae). Ecology of Freshwater Fish 12(2): 151-158.

Leung, L.K-P. 1988. Ultrastructure of the spermatozoon of Lepidogalaxias salamandroides and its phylogenetic significance. Gamete Research 19: 41-49.

Li, J, R. Xia, R.M. McDowall, J.A. Lopez, G. Lei & C. Fu. 2010. Phylogenetic position of the enigmatic Lepidogalaxias salamandroides with comment on the orders of lower euteleostean fishes. Molecular Phylogenetics and Evolution 57: 932-936.

Martin, K.L.M., T.M. Berra, & G.R. Allen. 1993. Cutaneous aerial respiration during forced emergence in the Australian salamanderfish, Lepidogalaxias salamandroides. Copeia 1993: 875-879.

McDowall, R.M. & Burridge, C.P. 2011. Osteology and relationships of the southern freshwater lower euteleostean fishes. Zoosystematics and Evolution 87(1): 7-185.

McDowall, R.M. & B.J. Pusey. 1983. Lepidogalaxias salamandroides Mees – a redescription, with natural history notes. Rec. West. Aust. Mus. 11: 11-23.

Mees, G. F. 1961. Description of a new fish of the family Galaxiidae from Western Australia. J. Roy. Soc. West. Aust. 44: 33-38.

Morgan, D.L., H.S. Gill & I.C. Potter. 2000. Age composition, growth and reproductive biology of the salamanderfish Lepidogalaxias salamandroides: a re-examination. Environ. Biol. Fish. 57: 204-2000.

Ogston, G., Beatty, S.J., Morgan, D.L., Pusey, B.J. & Lymbery, A.J. 2016. Living on burrowed time: Aestivating fishes in south-western Australia face extinction due to climate change. Biological Conservation 195: 235–244. https://doi.org/10.1016/j.biocon.2016.01.008 Abstract

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Quick Facts


CAAB Code:37102022

Biology:Aestivates during drought

Conservation:IUCN Near Threatened; WA Endangered

Conservation:IUCN: Near Threatened

Habitat:Semi-permanent freshwaters

Max Size:6.7 cm SL; 7.5 cm TL

Native:Endemic

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