Little Rainbowfish, Melanotaenia wilsoni Hammer, Allen, Martin, Adams & Unmack 2019

A Little Rainbowfish, Melanotaenia wilsoni, from the Northern Territory. Source: Michael Hammer / Northern Territory Museum. License: All rights reserved

A very small yellowish-brown rainbowfish becoming silvery-white below, with a series of 7–8 contrasting dark stripes (blackish, dark brown or purple), including a conspicuous midlateral stripe and a second conspicuous stripe along the lower side. The species has a small orange to red 'spot' on the upper gill cover, an area of orange sometimes on the breast and anterior part of the pelvic fins, and a silver to orangy iris. The dorsal and anal fins have a broad greyish to black somewhat diagonal band, with a pale yellow area above the band, often a whitish to light blue fin margin. The area below the dark band is pale yellow to orange with a row of scattered spots or blotches long the fin base. Males have distinctly dark markings on the second dorsal fin.

Cite this page as:
Bray, D.J. 2022, Melanotaenia wilsoni in Fishes of Australia, accessed 26 Sep 2023,

Little Rainbowfish, Melanotaenia wilsoni Hammer, Allen, Martin, Adams & Unmack 2019

More Info


Endemic a small area below the escarpment of the Tabletop Range in Litchfield National Park, Northern Territory - in small streams in sandy areas fed by springs off the Litchfield escarpment, namely Burton Creek (Finniss River system) and Tolmer and Sandy creeks (Reynolds River system). 
Inhabits very shallow small streams and pools in amongst thick Pandanus swamps with abundant aquatic vegetation and woody debris.


Lateral scales 30–34; Vertebrae 31–33.Male and female fin morphology similar; adpressed first dorsal fin of both sexes extending to base of second dorsal-fin spine; adpressed posterior rays of dorsal and anal fins extend about midway on caudal peduncle; first soft anal-fin ray of both sexes longer than remaining rays; 


Maximum size less than 35 mm SL.


Side of body with series of 7–8, well-contrasted dark stripes (blackish, purple to dark brown or purple) with males usually having noticeable dark markings on the second dorsal fin.


The species is bred in aquaculture facilities with limited wild harvest (broodstock).


The Little Rainbowfish had been misidentified as Melanotaenia maccullochi in most publications prior to 2019. As the common name suggests, this is the smallest known rainbowfish species.


The new species is named for David Wilson who was the first person to document the presence of the small isolated population in the Northern Territory, and has worked tirelessly and generously to promote the sustainable use and conservation of native aquatic animals, especially rainbowfishes.

Species Citation

Melanotaenia wilsoni Hammer, Allen, Martin, Adams & Unmack 2019, Zootaxa 4701 (3): 224, figs 5 & 8. Type locality: Sandy Creek, Reynolds River system, Litchfield National Park (13° 15.21ʹS, 130° 44.42ʹE), Northern Territory, 0.5 m.


Bray, D.J. 2022


Atlas of Living Australia

Little Rainbowfish, Melanotaenia wilsoni Hammer, Allen, Martin, Adams & Unmack 2019


Allen, G.R. 1995. Rainbowfishes in Nature and the Aquarium. Tetra-Verlag, 179 pp. (in part as Melanotaenia maccullochi)

Allen, G.R., Midgley, S.H. & Allen, M. 2002. Field Guide to the Freshwater Fishes of Australia. Perth : Western Australian Museum 394 pp. (in part as Melanotaenia maccullochi)

Armstrong, N. 1995. A dwarf maccullochi in the Northern Territory. Fishes of Sahul 9: 401–404. (as Melanotaenia maccullochi)

Cook, B.D., Unmack, P.J., Huey, J.A. & Hughes, J.M. 2012. Did common disjunct populations of freshwater fishes in northern Australia form from the same biogeographic events? Freshwater Science 33: 263–272. (in part as Melanotaenia maccullochi)

Hammer, M. 2019. Melanotaenia sp. nov. 'Darwin'. The IUCN Red List of Threatened Species 2019: e.T123357139A123382711. Accessed on 22 February 2022.

Hammer, M. 2019. One becomes three: research behind the naming of two new dwarf rainbowfishes in the Melanotaenia maccullochi species complex. Fishes of Sahul 33(4): 1492–1500. 

Hammer, M.P., Allen, G.R., Martin, K.C., Adams, M. & Unmack, P.J. 2019. Two new species of dwarf rainbowfishes (Atheriniformes: Melanotaeniidae) from northern Australia and southern New Guinea. Zootaxa 4701(3)
Larson, H.K. & Martin, K.C. 1989. Freshwater Fishes of the Northern Territory. Northern Territory Museum of Arts and Sciences, Darwin, 102 pp. (as Melanotaenia maccullochi)

Larson, H.K., Williams, R.S. & Hammer, M.P. 2013. An annotated checklist of the fishes of the Northern Territory, Australia. Zootaxa 3696(1): 001–293.  (as Melanotaenia maccullochi)

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

Pusey, B., Kennard, M. & Arthington, A. 2004. Freshwater Fishes of North-Eastern Queensland. CSIRO Publishing, Collingwood, Victoria, 684 pp.  (in part as Melanotaenia maccullochi)

Pusey, B.J., Burrows, D.W., Kennard, M.J., Perna, C.N., Unmack, P.J., Allsop, Q. & Hammer, M.P. 2017. Freshwater fishes of northern Australia. Zootaxa 4253(1): 1–104. (in part as Melanotaenia maccullochi

Schmida, G. 2015. Freshwater Fishes of Australia. Vol. 2. Nature-Shots. Lower Beechmont, Queensland, 182 pp. (in part as Melanotaenia maccullochi)

Tappin, A.R. 2010. Rainbowfishes: Their Care and Keeping in Captivity. Art Publications, Brisbane, 510 pp. (in part as Melanotaenia maccullochi)

Unmack, P.J., Allen, G.R. & Johnson, J.B. 2013. Phylogeny and biogeography of rainbowfishes (Melanotaeniidae) from Australia and New Guinea. Molecular Phylogenetics and Evolution 67: 15–27. (as Melanotaenia sp. NT)

Quick Facts

CAAB Code:37245029

Conservation:IUCN Vulnerable

Fishing:Aquarium fish

Habitat:Freshwater streams

Max Size:<4 cm TL


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