Fish
Chili Rasbora
Boraras brigittae · also called chili rasboras
Barely the length of a fingernail yet burning with an intense fiery red, a chili rasbora moves through a tight school of its own kind, proof that some of the most vividly coloured fish in the aquarium hobby also happen to be some of the smallest.
Overview
The chili rasbora, Boraras brigittae, is a tiny, intensely coloured schooling fish native to blackwater peat swamp and stream habitat on the island of Borneo in Southeast Asia. Its diminutive adult size, vivid red colouration, and strong dependence on soft, acidic blackwater conditions make it one of the most popular and visually striking small fish kept in nano aquariums worldwide.
Big colour, tiny body
Few fish manage to pack as much visual intensity into as small a body as the chili rasbora, whose fiery red colouring stands out sharply against the dark, tannin-stained water of its native blackwater habitat.
Status
Least Concern, remaining present across suitable blackwater habitat on Borneo, though the species depends on a habitat type facing ongoing pressure from land conversion in parts of its range.
Chili Rasbora: common questions
How small is the chili rasbora?
This species rarely exceeds about 2 centimetres in length as a fully grown adult, making it one of the smallest schooling fish commonly kept in aquariums anywhere in the world, and a favourite choice for small nano tanks that cannot accommodate larger schooling species.
Why does the chili rasbora need soft, acidic water?
This species is closely tied to soft, acidic, tannin-stained blackwater habitat in the wild, and while captive-bred stock has proven somewhat adaptable, it generally shows its most intense red colouration and greatest overall health when kept in conditions that closely mimic these natural blackwater parameters.
How many chili rasboras should be kept together?
This species shows its most natural schooling behaviour and best colour when kept in a group of ten or more, since smaller numbers can leave individuals visibly less confident, less active, and less vividly coloured than a properly sized school.
Where does the chili rasbora come from?
This species is native to blackwater peat swamp and stream habitat on the island of Borneo in Southeast Asia, a specialised acidic wetland environment shared with several other small, similarly colourful fish species.