Rasbora trilineata

Rasbora trilineata, the Scissortail Rasbora, is one of the most immediately recognisable rasboras in the hobby, named for its deeply forked tail fin with contrasting black-and-white tips that scissor as the fish swims. It is native to the Mekong basin and Sunda Islands of Southeast Asia, inhabiting open river channels and tributaries with moderate flow. Adults reach 15 cm, making it unsuitable for small aquaria. It needs a tank of at least 120 L with plenty of horizontal swimming room. Despite its size it is entirely peaceful and can be kept with comparably sized community fish. Groups of five or more produce the most impressive schooling behaviour. It accepts all standard aquarium foods and is unfussy about water chemistry within its preferred range. A classic species and a reliable, long-lived aquarium fish.

Water: Temperature 20–26 °C, pH 6.0–7.5, GH 5–15; moderate flow; clean, well-filtered water. Tank: 120 L minimum; long tank with extensive open swimming area; planted sides; very secure lid. Feeding: Flake, medium pellet, frozen bloodworm, daphnia, and brine shrimp; an eager feeder. Breeding: Egg-scatterer; large conditioning tank needed; rarely bred in hobby. Compatibility: Peaceful with all similarly-sized community fish; avoid keeping with nano species.