Strawberry Rasbora

The strawberry rasbora is a miniature cyprinid from the peat swamps of peninsular Thailand, reaching only 2 cm standard length. It was formally described as Boraras naevus in 2011 and is known from the lower Tapi river drainage near Surat Thani. The common name comes from the colour of breeding males: a warm reddish body with a prominent dark blotch on the flank that is noticeably larger in males than females — a feature unique to this species within the genus.

Despite its tiny size, the strawberry rasbora is not a beginner fish. It comes from soft, acidic blackwater and is sensitive to water chemistry swings. A biologically mature tank with a 45 × 30 cm base (about 41 litres), dense planting, floating plants and dark leaf litter is ideal. Lighting should be dim to moderate and filtration gentle — an air-driven sponge filter works well. The temperature can range from 20–28 °C and pH 5.0–7.0, with the lower end preferred for breeding.

In nature Boraras naevus is a micropredator feeding on tiny insects, worms and crustaceans. In the aquarium it needs a daily supply of small live or frozen foods — Daphnia, Artemia nauplii, microworm and cyclops — alongside finely crushed quality flakes. Dried foods alone are not sufficient for long-term health and colour.

These fish are extremely peaceful but timid. They are best kept in a species-only setup or with other diminutive species such as Microdevario, pygmy Corydoras, Otocinclus and small freshwater shrimp. Avoid housing them with other Boraras species because hybridisation may occur. A group of at least eight to ten will show the best colour and social behaviour. They are continuous egg-scatterers; in a densely planted tank small numbers of fry may appear without intervention.