Boesemani rainbowfish

Behaviour and habits

The Boesemani rainbowfish is a large, stunning shoaler whose males develop a deep blue front and a bright orange rear — one of the most spectacular freshwater fish. It is active and peaceful, needs length to swim, and shows its best colours once mature and settled in a group, the males displaying to one another in the open water. It lives for years and grows substantial, so it needs a genuinely large tank.

What to feed, and how often

Omnivore: a good flake or pellet plus frozen bloodworm, brineshrimp and mysis, with some vegetable matter. Feed once or twice a day — it is a big, active fish, so match the amount to its size and keep the water from fouling.

Water changes and maintenance

Change 25–30% weekly. Being large and active, it produces a lot of waste, so strong filtration and clean, harder water are needed to keep it in condition and colour. Its colours deepen with age and good care.

Care and how easy it is

Needs a long tank and a group of six or more; hardy and long-lived once settled, but not a fish for a small or cramped setup.

Common health problems

Prone to ich after transport; otherwise hardy.

If it gets sick

Quarantine new arrivals and treat ich early with warmth and medication, keeping the group under observation.