Boesemani rainbowfish
Melanotaenia boesemani
easy careOverview
The boesemani rainbowfish (Melanotaenia boesemani) is one of the most striking mid-water shoalers in the hobby — mature males split from steel-blue at the head to blazing orange at the tail. Peaceful, hardy and tireless swimmers, they suit a spacious community, but that word “spacious” matters: these are 10 cm fish that need length to swim and a proper group to look their best.
Tank & water
Give a shoal at least 200 litres (50 gallons), prioritising tank length over height.
- Temperature: 24–28 °C from a steady heater.
- Water: neutral to slightly alkaline, pH 7.0–8.0 and moderately hard; test with a kit and see is tap water safe.
- Open swimming space: plant the sides and back but leave an open channel for their constant cruising.
- Filtration: a good filter with some flow, plus regular water changes.
Feeding
Boesemani are active omnivores with healthy appetites to fuel their swimming. Feed a quality flake or small pellet staple plus frozen bloodworm, brine shrimp, daphnia and some vegetable matter or spirulina. Feed once or twice daily; their energy means they rarely leave food uneaten.
Tankmates
Excellent, peaceful community fish for a roomy tank. They pair well with other rainbowfish, larger tetras, rasboras, barbs, corydoras and peaceful cichlids like the Bolivian ram. Their size keeps them safe from most predators, and their speed keeps them clear of fin-nippers. Combine with the dwarf neon rainbowfish for a multi-species rainbow display. Check how many fish in an aquarium for stocking.
Boesemani rainbowfish — frequently asked questions
How many boesemani rainbowfish should I keep?
At least six, and more if you have room. They are shoaling fish that colour up and behave naturally in a group, while males display their best to each other. A single fish or a pair looks washed out and can be nervous, so buy a group from the start.
Why do my boesemani rainbowfish look dull?
Juveniles and stressed fish are pale. Colour develops with age, a good group, a varied diet and stable water, and males intensify their blue-to-orange split when displaying. A cramped tank, poor diet or being kept singly all keep them looking grey.
Do boesemani rainbowfish need hard water?
They prefer neutral to slightly alkaline, moderately hard water — around pH 7.0–8.0 — reflecting their New Guinea highland streams. They tolerate a range, but very soft, acidic water is not ideal and can dull their colour over time.
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