Western Rainbowfish Care Guide - Aquarium Setup, Diet & Breeding

Western rainbowfish are active, peaceful members of the Melanotaeniidae family, recognised for their elongated bodies, large eyes and shimmering scales. Mature males can develop rich blue, green, bronze and golden tones, often with contrasting reddish or orange fins, while their colours become especially striking when displaying to females or competing with other males.

They are sociable fish with lively, open-water swimming habits. Males frequently posture alongside one another, spreading their fins and intensifying their colours without usually causing serious harm. Females are generally less brightly marked, but a well-kept group remains attractive and constantly active.

In the wild, this species occupies a wide range of clear and stained freshwater habitats, from flowing streams to quiet pools and floodplain billabongs. These environments can experience substantial seasonal changes in water level, flow, temperature and chemistry.

Western rainbowfish are an adaptable Australian native species and a good choice for a spacious community aquarium. Their energetic nature and preference for living in groups make them most impressive when given plenty of swimming room and kept with other peaceful, similarly sized fish.

Western rainbowfish are native to northern and western Australia, particularly the Kimberley and Pilbara regions of Western Australia, with populations extending into parts of the Northern Territory. They inhabit freshwater creeks, rivers, pools, billabongs and seasonal waterways across tropical and subtropical savannah landscapes.

A group of Western rainbowfish should ideally be housed in an aquarium of at least 180 litres, with a footprint around 120 cm long by 40 cm wide. They are energetic swimmers and benefit more from length and open swimming space than from a very tall aquarium. Use a secure lid, efficient filtration and good oxygenation, while leaving broad areas open at the front and centre. A fine gravel or sand substrate, hardy plants, driftwood and smooth rocks can provide cover without obstructing their swimming room. Moderate to strong water movement is suitable, provided quieter areas are also available.

Males reach about 12 cm (4.7 inches) in total length, while females are usually smaller at around 10 cm (3.9 inches).

Western rainbowfish are omnivores and should receive a varied diet of quality tropical flakes, small pellets and granules. Supplement these foods with frozen or live offerings such as brine shrimp, daphnia, mosquito larvae and bloodworm. Regular vegetable matter, including spirulina-based foods, helps provide a balanced diet and supports their colour and condition. Feed modest portions once or twice daily, ensuring all food is eaten promptly.

Western rainbowfish can live with other peaceful, active community fish of a similar size. Suitable companions include other rainbowfish, larger peaceful tetras, danios, rasboras, peaceful barbs, Corydoras, bristlenose catfish and many peaceful loaches. Avoid fin-nipping species, highly aggressive fish and very small, slow-moving tankmates that may be intimidated by their activity. They should not be housed with large predatory cichlids or other fish likely to harass them.

Western rainbowfish are egg scatterers that can be bred in a separate spawning aquarium. Condition a group with nutritious foods, then provide fine-leaved plants or spawning mops for the adhesive eggs. Spawning may occur regularly, with eggs deposited over several days. Remove the mop or eggs to a hatching container, as the adults may eat them. The fry usually hatch after about one to two weeks and need very small first foods, such as infusoria or commercially prepared fry food, before progressing to newly hatched brine shrimp.

Males are typically larger and deeper-bodied than females, with more intense metallic colouration and longer, more extended dorsal and anal fins. Females are generally slimmer and paler, with shorter fins and less pronounced colour displays.