Madagascar Rainbowfish Care Guide - Aquarium Tips, Diet & Breeding

Madagascar Rainbowfish are elegant, laterally compressed fish with a long, streamlined body and a deeply forked tail. Their sides typically show a silvery to golden sheen crossed by a dark horizontal line, while the fins may display yellow, orange, red or bluish tones. Mature males are usually the more colourful sex, especially when displaying to females or competing with other males.

This species is active and sociable, spending much of its time in the middle and upper areas of the aquarium. Groups create a lively display as the fish swim together, with males periodically extending their fins and flashing their colours during courtship and social contests.

In the wild, Madagascar Rainbowfish are associated with clear, flowing freshwater habitats and marginal vegetation. Their natural environment can vary from quiet stream edges to faster sections of rivers, and submerged roots, branches and plants provide shelter and feeding areas.

Bedotia madagascariensis is one of Madagascar’s native rainbowfish and belongs to the Bedotiidae family rather than the Melanotaeniidae family that contains many Australian rainbowfish. It is a striking but increasingly conservation-sensitive species, making responsible sourcing particularly important for aquarists.

Madagascar Rainbowfish are endemic to eastern Madagascar, an island nation off the southeastern coast of Africa. They inhabit freshwater rivers, streams and associated habitats, although wild populations are threatened by habitat loss, introduced species and collection pressure.

A group should have at least a 120-litre aquarium, with a footprint of roughly 100 cm by 40 cm so these active swimmers have adequate horizontal space. Use a secure cover because the species can jump, and combine open swimming areas with dense planting around the sides and back. A dark sand or fine-gravel substrate, smooth roots, branches and some floating vegetation create a natural-looking layout, while good filtration and gentle, well-oxygenated water movement suit their riverine background. Leave the front and central areas open for swimming.

Males can reach about 10 cm (4 in) in total length, while females are usually smaller at around 8 cm (3.1 in).

Madagascar Rainbowfish are omnivorous and do best on a varied diet of quality flakes and small floating or slow-sinking pellets supplemented with frozen or live foods. Daphnia, mosquito larvae, brine shrimp and bloodworm can provide useful variety, while suitably sized insect-based foods support their natural preference for small aquatic and terrestrial invertebrates. Occasional vegetable-based foods can also be offered as part of a balanced feeding routine.

Madagascar Rainbowfish are generally peaceful community fish, although their energetic swimming and occasional male-to-male displays can unsettle very timid species. Suitable companions include similarly sized rainbowfish, larger peaceful tetras, danios, barbs, peaceful gouramis, loaches and robust catfish. Avoid housing them with fin-nipping species, highly aggressive cichlids or very small, slow-moving fish that may be outcompeted for food. They should not be kept with fish small enough to be swallowed.

Madagascar Rainbowfish are egg scatterers that can be bred in a separate spawning aquarium containing fine-leaved plants or spawning mops. A conditioned group will usually deposit adhesive eggs over several days. Remove the spawning material or eggs to protect them from predation, then incubate them in gently aerated, clean water. Hatching usually takes around one to two weeks, and the tiny fry can initially be fed infusoria or commercially prepared fry food before progressing to newly hatched brine shrimp.

Males are generally larger and more vividly coloured, with fuller fins and stronger red, orange or bluish markings. Females are typically shorter-bodied, less intensely coloured and have more rounded, less extended fins.