Eacham Rainbowfish

Melanotaenia eachamensis is one of Australia's most critically endangered freshwater fish, known only from Lake Eacham, a volcanic crater lake in the Atherton Tablelands of Queensland. The species was presumed extinct in the wild for many years after the introduction of non-native fish, but conservation breeding programs and subsequent reintroductions have helped stabilise small wild populations. Captive-bred specimens remain vital ambassadors for their species.

In the aquarium, Eacham Rainbowfish display a refined, understated beauty — a silver body overlaid with a soft blue-green iridescence, pale yellow on the lower flanks, and delicate fin colouration. They are not as flashy as some relatives, but their rarity and ecological significance make them extraordinarily special. They prefer cooler, soft to moderately hard, slightly acidic to neutral water reflecting their mountain lake origin.

Keeping Eacham Rainbowfish responsibly means maintaining accurate provenance records and participating in species studbooks where available. They should be kept in groups of at least six in a well-planted, quiet aquarium, and paired or group spawning can be carried out on fine-leaved plants or spawning mops to contribute to captive conservation efforts.

Water: Cooler temperatures preferred; pH 6.5–7.5, temperature 22–26°C, GH 5–12, KH 2–6. Tank: Minimum 120 L; species tank or quiet community strongly recommended; dense planting with soft substrate. Feeding: Accepts quality flake, micropellets, and small live or frozen foods such as daphnia and brine shrimp nauplii. Breeding: Egg scatterer among fine plants or mops; separate eggs for best survival rates and maintain breeding records. Compatibility: Best with small, very peaceful species; avoid boisterous or nippy tankmates.