Brilliant Rasbora

Brilliant Rasbora, Rasbora borapetensis, is a Southeast Asian cyprinid native to Thailand, Laos, Cambodia, Vietnam, and parts of Malaysia, primarily within the Mekong and Chao Phraya river systems. It inhabits rivers, streams, floodplain waters, and rice paddies with moderate flow, sandy or silty substrates, and vegetation along the margins. These environments are typically warm, well oxygenated, and seasonally variable.

Adult Brilliant Rasboras typically reach about 2 to 2.5 inches in length. The body is slender and streamlined with a bright silver to pale gold base coloration. A distinct dark lateral stripe runs from the snout through the body, often accented by a lighter golden or iridescent line above it. The caudal fin shows orange to reddish coloration, which becomes more noticeable in healthy, well-conditioned fish. The overall look is clean, reflective, and active rather than heavily patterned.

A tank of at least 20 gallons is recommended for a proper group. Brilliant Rasboras are schooling fish and should be kept in groups of eight or more to reduce stress and encourage natural behavior. The aquarium should provide open swimming space with plants and structure along the edges. Moderate water movement is preferred.

Water conditions should be stable and clean. Temperatures between 72 and 80 degrees Fahrenheit are appropriate, with a pH range of roughly 6.5 to 7.5 and soft to moderately hard water. This species is adaptable and does well in a wide range of conditions as long as water quality is maintained.

Feeding Brilliant Rasboras is easy. In nature they feed on insects, larvae, and small aquatic organisms. In the aquarium they readily accept flakes, micro-pellets, and frozen foods such as daphnia, brine shrimp, and cyclops. A varied diet supports health and coloration.

Temperament is peaceful and active. Brilliant Rasboras are excellent community fish and do well with other small to medium non-aggressive species. Suitable tankmates include other rasboras, danios, tetras, and peaceful bottom dwellers. They are fast swimmers but not aggressive.

Breeding is possible in captivity. They are egg scatterers that deposit eggs among plants or substrate. Adults do not provide parental care and may consume eggs if left in the breeding tank.

Rasbora borapetensis is a hardy, active schooling fish that combines bright reflective coloration with constant movement. Its adaptability and peaceful nature make it an excellent choice for community aquariums.