Pygmy Rainbowfish, Melanotaenia pygmaea Allen 1978

Other Names: Pygmy Rainbow Fish

A male Pygmy Rainbowfish, Melanotaenia pygmaea. Source: Gerald R. Allen. License: All rights reserved


A small metallic sky-blue rainbowfish with a blackish mid-lateral stripe, and pale yellow fins. Males are larger than females, and are more brightly coloured, with a reddish head and whitish fins. Females lack the reddish head and have smaller and more rounded fins.

The Pygmy Rainbowfish occurs only in the Prince Regent River region of north Western Australia.

Cite this page as:
Martin F. Gomon & Dianne J. Bray, Melanotaenia pygmaea in Fishes of Australia, accessed 19 May 2024,

Pygmy Rainbowfish, Melanotaenia pygmaea Allen 1978

More Info


Known only from two small tributaries of Prince Regent River, in the Western Kimberley region of Western Australia.

Occurs in schools of up to 50 or more individuals in freshwater pools and rivulets on sandstone terraces, often at the base of small waterfalls and rapids.


Meristic features: Dorsal fin V-VII + I, 8-11; Anal fin I, 14-18; Pectoral fin 12-14.

Body relatively elongate and compressed; males with a distinctive humped profile; greatest body depth (specimens > 25 mm SL): males 30.2-35.7, females 24.2-30.4; head length 35.6-36.6; snout length 5.9-8.0; eye diameter 9.1-9.7; jaw teeth conical, vomer with a solid band of well-developed teeth; teeth present on palatines; lateral line absent.

Scales cycloid to slightly crenulate with well-developed radii ;large, horizontal scale rows 8 or 9; vertical scale rows 31 to 33.

Two separate dorsal fins, anal fin long-based, caudal fin moderately forked.


To 5.5 cm SL, commonly to 4cm or less


Metallic sky-blue dorsolaterally, dark mid-lateral stripe and pale yellow to whitish fins. Males orange on nape, snout, breast and belly.


Feed on small aquatic and terrestrial insects and microcrustaceans.


Become sexually mature at 23 mm SL; oviparous with demersal eggs.

Species Citation

Melanotaenia pygmaea Allen, 1978, Trop. Fish Hobbyist 26(10): 99. Type locality: Cascade Creek, WA.


Martin F. Gomon & Dianne J. Bray

Pygmy Rainbowfish, Melanotaenia pygmaea Allen 1978


Allen, G.R. 1978. The rainbowfishes of northwestern Australia (family Melanotaeniidae). Tropical Fish Hobbyist 26(10): 91-102 figs 1-15

Allen, G.R. 1982. Inland Fishes of Western Australia. Perth : Western Australian Museum 86 pp. 6 figs 20 pls.

Allen, G.R. 1989. Freshwater Fishes of Australia. Neptune, New Jersey : T.F.H. Publications 240 pp., 63 pls.

Allen, G.R. & Cross, N.J. 1982. Rainbowfishes of Australia and Papua-New Guinea. New Jersey : T.F.H. Publications 142 pp. figs.

Allen, G.R., Midgley, S.H. & Allen, M. 2002. Field Guide to the Freshwater Fishes of Australia. Perth : Western Australian Museum 394 pp.

Leggett, R. & Merrick, J.R. 1987. Australian Native Fishes for Aquariums. Artarmon : J.R. Merrick Publications 241 pp. 142 figs.

Merrick, J.R. & Schmida, G.E. 1984. Australian Freshwater Fishes Biology and Management.  Sydney : J.R. Merrick 409 pp.

Wager, R. 1996. Melanotaenia pygmaea. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. <>. Downloaded on 5 November 2012.

Quick Facts

CAAB Code:37245011

Conservation:IUCN Near Threatened

Habitat:Clear freshwaters

Max Size:5.5 cm SL


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Species Maps

CAAB distribution map