Boraras brigittae
True nano fish, shines in a planted blackwater scape with botanicals and tannins. Easily out-competed by larger tank mates; best as a species-only display.
Chili Rasbora (Boraras brigittae) reaches 1.7–2 cm as an adult and needs a minimum tank of 30 L. Native to Southwestern Borneo blackwater swamps, it lives in the mid to top water column with a peaceful temperament. Aim for 24–28 °C, pH 4.0–6.5, and 1–4 dGH hardness. Lifespan is 3–4 years with good care. Keep chili rasbora in groups of 10+, yes schoolers need numbers to display natural behaviour. Diet: micropredator, Powder fry food, micro pellets, baby brine shrimp, microworms. Plant-safe: Yes. Shrimp-safe: Yes (adults and adult shrimp).
Care at a glance
True nano fish, shines in a planted blackwater scape with botanicals and tannins. Easily out-competed by larger tank mates; best as a species-only display.
By Mike ElmiraUpdated 2 min read
Part of our complete guide to aquarium fish for the planted tank.
The parameters that decide whether chili rasbora fits in your tank.
Mid to Top
Yes
Group of 10+
Cyprinidae
Micropredator
Powder fry food, micro pellets, baby brine shrimp, microworms.
3–4 yrs
Hard
Tea-coloured peat-swamp pools of Borneo
Southwestern Borneo blackwater swamps
Tank-mate safety and the species this one is documented to thrive (or fail) alongside.
Best as species-only or with similar tiny fish: sparkling gouramis, pygmy corydoras, ember tetras (in larger tanks). Cherry shrimp adults coexist fine.
Anything larger than ~4 cm. They are food, not company.
Hard-won lessons from the tank.
These are quite literally peat-bog fish. Replicating that is non-negotiable for long-term health. A planted blackwater nano with 20+ chilis is one of the most rewarding small displays in the hobby.
Species 'brigittae' honours German aquarist Brigitte Schmidt.
What can go wrong and how to spot it.
Failure modes, in order of how dramatic the fix is.
Sensitive shippers. Mycobacterial outbreaks are unfortunately common in mass-imported fish. Quarantine and observe for wasting/spinal deformities.
Often sold mixed with B. maculatus (Phoenix rasbora) or B. merah (Merah chili) — these are different species and may not breed together. Check the spot pattern.
The practical routine, read top to bottom.
Dedicated nano blackwater — 20 L+. Sand or peat substrate. Catappa leaves, alder cones, mangrove root. Floating plants and Riccia. Sponge filter only — they cannot handle current.
Critical. 4+ weeks. Examine for any deformity or wasting before moving to display.
Where it comes from, how it behaves, and the variants you'll see at retail.
Where it lived before it came home.
Forest peat swamps in southwest Borneo (Indonesia). Tannin-black, extremely acidic (pH 3.5–5.5), very soft, slow-moving water with heavy leaf litter.
Tiny zooplankton, mosquito larvae, micro-crustaceans.
Habitat loss in Borneo is a real concern as peat swamps are converted to palm oil. The aquarium trade currently does not threaten the species, but its long-term wild status is uncertain.
How they pair, reproduce, and grow.
Males are slimmer and more brightly coloured (intense red). Females rounder with paler colour.
Possible but tricky — needs soft, acidic, tannin-rich water, dim lighting, and a thick layer of moss/Riccia for eggs to fall into. Adults eat eggs. Fry are tiny; need infusoria/vinegar eels for first weeks.
The named cultivars and the lookalikes worth flagging.
Wild type only. Brigittae is sometimes confused with B. maculatus and B. urophthalmoides.
Direct answers to the questions search engines and AI assistants surface most often about this species.
Chili Rasbora (Boraras brigittae) needs a minimum tank of 30 L. They live in the mid to top water column and should be kept in groups of 10+, so a longer footprint matters more than depth.
Target 24–28 °C, pH 4.0–6.5, and 1–4 dGH hardness. Acclimate slowly when moving them between water sources.
Shrimp safety: Yes (adults and adult shrimp). Plant safety: Yes.
Chili Rasbora are micropredator. Powder fry food, micro pellets, baby brine shrimp, microworms.
On Fin & Stem's 1–5 difficulty scale this species rates 3/5. Intermediate, stable parameters and a mature tank matter. Breeding difficulty: hard.
Typical lifespan in a well-maintained tank is 3–4 years.
A planted tank is a system. Pair this fish with one entry from each other pillar to plan the whole scape.
