Duboulay's Rainbowfish

Melanotaenia duboulayi — the Crimson-spotted Rainbowfish — is one of the most familiar and widely kept Australian native fish, found naturally along the eastern seaboard rivers of New South Wales and southern Queensland. Adult males in peak condition develop a brilliant silver-blue to blue-green iridescent body with vivid red spot markings along the mid-lateral scale rows and attractive orange-yellow fins, making them genuinely eye-catching in a well-lit aquarium.

This species is an ideal entry point into Australian rainbowfish keeping. It is hardy, adaptable, peaceful, and tolerates a wider range of temperatures than many tropical species — making it suitable for unheated aquariums in temperate climates or tropical community tanks. It is fast-growing, long-lived by small-fish standards, and breeds readily in captivity, making it rewarding at every stage.

Melanotaenia duboulayi is widely available from aquarium shops in Australia and from specialist suppliers in Europe and North America. It thrives in groups of six or more and brings excellent activity and colour to any community aquarium. Regular feeding on a varied diet including live and frozen components brings out the best red spotting in mature males.

Water: pH 6.5–7.5, temperature 18–26°C, soft to moderately hard; one of the most adaptable rainbowfish available. Tank: Minimum 120 L; planted aquarium with open swimming zone; unheated subtropical setups work well. Feeding: Quality flake and pellets; live and frozen daphnia, brine shrimp, and bloodworms develop the red spotting. Breeding: Prolific egg scatterer; will spawn readily among plants without special conditioning. Compatibility: Outstanding peaceful community species; compatible with most temperate and subtropical fish.