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 / License: CC BY Attribution-Noncommercial


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 16 Apr 2024,

Murray River Rainbowfish, Melanotaenia fluviatilis (Castelnau 1878)

More Info


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.


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.


To 11 cm SL, commonly to 8.5 cm.


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).


Omnivores - feed on aquatic and terrestrial invertebrates and some filamentous algae.


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.


Martin F. Gomon & Dianne J. Brray


Names list:

  • Aristeus fluviatilis Castelnau, 1878
  • Melanotaenia neglecta Rendahl, 1922
  • Murray River Rainbowfish, Melanotaenia fluviatilis (Castelnau 1878)


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    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.

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    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.

    Quick Facts

    CAAB Code:37245007

    Behaviour:Swims in schools near surface


    Max Size:11 cm SL


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