Dwarf rainbowfish
Small, iridescent freshwater fish from West Papua.
The dwarf rainbowfish is a tiny, bright blue species native to the Mamberamo River basin in Indonesia. It is popular in home aquariums for its vivid colours and active schooling behaviour. Keepers value it for being relatively easy to breed and peaceful when housed in proper groups.
- Native to Mamberamo River basin in Indonesia
- Males are brighter and have deeper bodies
- Spawns continuously for several days
- Requires a tank of at least 15 gallons
- Hatches within one week of spawning
What it is
This small fish belongs to the rainbowfish subfamily. Adults typically reach five centimetres, though some grow to eight. Males display deeper bodies and brighter hues than females. Their scales shine with an iridescent blue, complemented by colourful fins. The species is energetic and known to leap from the water surface.
Where it lives
It lives only in the Mamberamo River basin within West Papua, Indonesia. These fish inhabit small tributaries that move slowly through rainforest regions. They stay near the surface of these native waters, preferring the shelter and cover provided by the surrounding vegetation.
How it lives
The dwarf rainbowfish is an omnivore that schools near the river surface. In captivity, a varied diet including leafy greens and live foods like brine shrimp enhances their colour. Males may spar, particularly in the morning, but they are generally peaceful if kept in adequate numbers.
Breeding and life cycle
This species scatters eggs, making it straightforward to breed. Spawning occurs in the early morning, where males circle and nip each other while displaying intense iridescence. Females release eggs continuously over several days, and males fertilise them immediately. The young hatch within a week.
Fish and people
Aquarists prize this fish for its vivid appearance. Tanks should hold at least fifteen gallons with plenty of plants to mimic overhead cover. Groups of six or more are essential, with more females than males to reduce aggression. They thrive in tropical conditions around twenty-five degrees Celsius.
Questions people ask about Dwarf rainbowfish
How big do dwarf rainbowfish get?
They usually reach five centimetres in length. Some individuals have been reported to grow up to eight centimetres. Males tend to be slightly larger and deeper-bodied than females.
Are dwarf rainbowfish aggressive?
They are generally peaceful but males will spar, especially in the morning. Keeping a school of at least six with more females than males helps disperse aggression and limits infighting.
What do dwarf rainbowfish eat?
They are omnivorous. A varied diet is best, including diced leafy greens and occasional live foods like mosquito larvae or brine shrimp. This stimulates instincts and enhances their natural colours.
Good reading and sources
- Dwarf rainbowfish on WikipediaEncyclopedia
- More photos on Wikimedia CommonsPhotos
- Wikidata recordOpen data
The facts on this page come from the Wikipedia article "Dwarf rainbowfish", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). EveryFish rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.
It may contain mistakes, and figures change over time. Nothing here is investment or buying advice. If something is wrong, tell us. Last refreshed 2026-11-15.
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