Murray River Rainbowfish, Melanotaenia fluviatilis (Castelnau 1878)

Other Names: Australian Rainbowfish, Crimson-spotted Jewelfish, Crimson-spotted Jewel-fish, Crimson-spotted Rainbow Fish, Crimson-spotted Rainbowfish, Crimson-spotted Ranibow Fish, Murray River Sunfish, Murray-Darling Sunfish, Pink Ear, Pink-ear, Pink-eared Rainbowfish, Rainbow-fish

Murray River Rainbowfish, Melanotaenia fluviatilis. Source: Gunther Schmida / http://www.guntherschmida.com.au. License: CC BY Attribution-Noncommercial

Summary:

The Murray River Rainbowfish is the southern-most species in the family Melanotaeniidae.

Identifying features:
Colour variable - silvery-green on sides and above, whitish below (juveniles are translucent);
Scales with a brownish margin;
Gill cover with a pink to reddish spot.

Males have red spots on the dorsal, anal and caudal fins, with a blackish margin when breeding.

Cite this page as:

Martin F. Gomon & Dianne J. Brray, Melanotaenia fluviatilis in Fishes of Australia, accessed 23 Apr 2025, https://fishesofaustralia.net.au/home/species/2107

Murray River Rainbowfish, Melanotaenia fluviatilis (Castelnau 1878)

More Info

Distribution	Known from Roma, QLD to the Murray River, NSW, VIC and SA. The Campaspe River and the Goulburn River, VIC, represent the southern distribution limit. Forms schools in slow-flowing freshwater rivers, wetlands and billabongs.
Features	Meristic features: Dorsal-fin rays: V-VII; I, 10-13 Anal-fin rays: I, 17-21 Pectoral-fin rays: 13-15 Body strongly laterally compressed, slender but becoming deeper with age; greatest body depth (adults > 50 mm SL): males 30.5-37.2, females 28.3-29.8; head of moderate size, head length 25.9-29.4; anterior concavities in dorsal and ventral profiles; snout broadly rounded, length in SL 6.5-7.8; eye large, positioned dorsolaterally, diameter in SL 9.2-10.8; mouth moderately large, oblique and upturned; jaw with several rows of small conical teeth; teeth present on vomer, palatines and base of tongue. Scales relatively large, thin, horizontal scale rows 10 to 13; vertical scale rows 33 to 36; predorsal scales 14 to 18; preopercle-suborbital scales 8 to 14. Two dorsal fins separated by a small gap, origin of first closer to snout than tail; 1st dorsal fin short based, 2nd long based; anal fin long based; caudal fin moderately forked.
Size	To 11 cm SL, commonly to 8.5 cm.
Colour	Colour varies with sex, age and habitat; generally silvery with a greenish irridescence and whitish on lower head and belly; most scales with a brownish margin; pink to reddish spot on operculum; males with red spots on dorsal, caudal and anal fins and fins of breeding males with a black margin (females and immatures with clear fins).
Feeding	Omnivores - feed on aquatic and terrestrial invertebrates and some filamentous algae.
Biology	Usually breed during spring and summer when water temperatures exceed 20°C. Over a number of days, females deposit a few adhesive eggs at a time onto vegetation. Eggs - 1.3-1.8 mm diameter. Larvae hatch at 2.0-3.7mm TL after about a week, and cling to plants for around 2 days before becoming free-swimming.
Species Citation	Aristeus fluviatilis Castelnau, 1878, Proc. Linn. Soc. N.S.W. (1)3(2): 141. Type locality: Murrumbidgee River, NSW, Ropes Creek, near Sydney.
Author	Martin F. Gomon & Dianne J. Brray
Resources	Names list: Aristeus fluviatilis Castelnau, 1878 Melanotaenia neglecta Rendahl, 1922

Murray River Rainbowfish, Melanotaenia fluviatilis (Castelnau 1878)

References

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

Backhouse, G.N.& D.J. Frusher. 1980. The crimson-spotted rainbowfish, Melanotaenia fluviatilis (Castelnau 1878). Vict. Nat. 97: 144-148.

Cadwallader, P.L. & Backhouse, G.N. 1983. A Guide to the Freshwater Fish of Victoria. Melbourne : F.D. Atkinson Government Printer 249 pp.

Castelnau, F.L. de 1878. On some new Australian (chiefly) freshwater fishes. Proceedings of the Linnean Society of New South Wales 1 3(2): 140-144

Crowley, L.E.L.M., Ivantsoff, W. & Allen, G.R. 1986. Taxonomic position of two crimson-spotted rainbowfish, Melanotaenia duboulayi and Melanotaenia fluviatilis (Pisces: Melanotaeniidae), from Eastern Australia, with special reference to their early life-history stages. Aust. J. Mar. Freshwat. Res. 37: 385–398

Grant, E.M. 1975. Guide to Fishes. Brisbane : Queensland Government, Co-ordinator General’s Department 640 pp.

Grant, E.M. 2002. Guide to Fishes. Redcliffe : EM Grant Pty Ltd 880 pp.

Growns, I. 2004. A numerical classification of reproductive guilds of the freshwater fishes of south-eastern Australia and their application to river management. Fisheries Management and Ecology 11(6): 369-377.

Humphries, P., A.J. King & J.D. Koehn. 1999. Fish, flows and flood plains: links between freshwater fishes and their Environment in the Murray-Darling River System, Australia. Environmental Biology of Fishes 56(1-2): 129-151.

King, A.J. 2004. Ontogenetic patterns of habitat use by fishes within the main channel of an Australian floodplain river. Journal of Fish Biology 65(6): 1582–1603.

Koehn, J.D. & O'Connor, W.G. 1990. Biological information for management of native freshwater fish in Victoria. Department of Conservation and Environment, Victoria,

Leggett, R. & Merrick, J.R. 1987. Australian Native Fishes for Aquariums. Artarmon : J.R. Merrick Publications 241 pp.

Lintermans, M. 2007. Fishes of the Murray Darling Basin. An Introductory Guide. Murray-Darling Basin Commission, Canberra, Australia.

Lloyd, L.N. & K.F. Walker. 1986. Distribution and conservation status of small freshwater fishes in the River Murray, South Australia. Transactions of the Royal Society of South Australia 110: 40-57.

McDowall, R.M. 1996. Freshwater Fishes of South-eastern Australia. Sydney : Reed Books 2nd Edn 247 pp.

McGuigan, K.L., D. Zhu, G.R. Allen & C. Moritz. 2000. Phylogenetic relationships and historical biogeography of melanotaeniid fishes in Australia and New Guinea. Marine and Freshwater Research 51: 713-723.

Milton, D.A. & A.H. Arthington. 1984. Reproductive strategy and growth of the crimson-spotted rainbowfish, Melanotaenia splendida fluviatilis (Castelnau) (Pisces : Melanotaeniidae) in south-eastern Queensland. Australian Journal of Marine and Freshwater Research 35(1): 75-83.

Reid, H.P. & D.A. Holdway. 1995. Early development of the Australian crimson-spotted rainbowfish, Melanotaenia fluviatilis (Pisces: Melanotaeniidae). Marine and Freshwater Research 46(2): 475 - 480.

Smith, B.B., Conallin, A. & Vilizzi, L. 2009. Regional Patterns in the Distribution, Diversity and Relative Abundance of Wetland Fishes of the River Murray, South Australia. Transactions of the Royal Society of South Australia 133(2): 339-360.

Wedderburn, S. & Hammer, M. 2003. The Lower Lakes fish inventory: distribution and conservation of freshwater fishes of the Ramsar Convention wetland at the terminus of the Murray-Darling Basin, South Australia. Native fish Australia (SA) Inc., Adelaide. 38 p.