Clown rasbora

The clown rasbora is a larger, more robust member of the Rasbora genus, hailing from the blackwater streams and peat swamp forests of Sumatra, Borneo, and the Malay Peninsula. It is named for its bold two-spot pattern — a dark blotch behind the gill cover and a second at the base of the tail — set against a warm orange-pink body. Males develop a deeper red flush and slimmer build, while females are fuller-bodied and slightly paler. At up to 10 cm in length, it is one of the bigger rasboras and has a strong, purposeful swimming style that gives it more presence than its smaller relative species.

Despite its size, the clown rasbora is peaceful and shy by nature, particularly if kept in insufficient numbers. A group of eight to twelve individuals is strongly recommended — they are schooling fish that become nervous and reclusive when the group is too small. In a good-sized group, males display vibrant colours and dancelike fin displays that are among the most striking of any rasbora. Tankmates should be similarly sized and peaceful: larger tetras, other rasboras, Corydoras catfish, and medium-sized gouramis all work well. Avoid very small or timid species that may be stressed by their activity level. They are omnivorous with a preference for live and frozen foods — bloodworms, daphnia, and brine shrimp bring out their best colour — but will also accept high-quality flakes and micropellets.

The clown rasbora requires surprisingly generous space for a fish of its size: a tank with base dimensions of at least 120 by 45 cm, equating to roughly 255 litres. This is because they are extremely active swimmers that need room to streak across the tank. The water should be soft (2 to 10°H) and acidic, with a pH of 5.0 to 7.5 and temperature of 23 to 28°C. Heavy planting, floating plants, driftwood, and dimmer lighting that mimics their tannin-stained natural habitat help them feel secure. A tight-fitting lid is essential — they are accomplished jumpers. Like most rasboras, they are egg-scatterers with no parental care. The eggs hatch in about 24 to 48 hours, and the free-swimming fry require infusoria as a first food. Though not a fish for small tanks, the clown rasbora rewards keepers who can provide the space it needs with a display of constant motion and subtle brilliance.