Despite the many similarities between M. duboulayi and M. fluviatilis, they were recognised as separate species in 1986 because of genetic, morphometric, and meristic differences.

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

[5] Females are less intensely coloured, lacking some of the brilliance and red stripes along the caudal peduncle.

[6] Murray River rainbowfish are omnivorous and feed on both aquatic and terrestrial invertebrates and some filamentous algae.

[7] Murray River rainbowfish are native to southeastern Australia in freshwater systems west of the Great Dividing Range, particularly the Murray-Darling basin in New South Wales and southern Queensland.

[5] They are very adaptable and inhabit rivers, creeks, drains, ponds and reservoirs, and occasionally stagnant waterholes.