Dwarf Scissortail Rasbora

The Dwarf Scissortail Rasbora, scientifically known as Rasbosoma spilocerca, is a tiny and peaceful cyprinid from the Mekong basin of Southeast Asia (especially parts of Laos and Cambodia). It is distinct from the larger common Scissortail Rasbora and prized for its miniature size and elegant schooling behavior.

Adults only reach about 1 to 1.2 inches (2.5 to 3 cm) in length. Their bodies are slender, translucent silvery with subtle hints of blue or green sheen, and their caudal fin is deeply forked, giving the appearance of a small pair of scissors and a graceful swimming style.

A tank of at least 10 gallons is suitable for a small school. These fish are best kept in groups of eight or more to bring out their natural behavior and reduce stress. Provide fine sand or smooth gravel substrate, floating plants, driftwood or roots, and open swimming areas with soft lighting and gentle water movement to simulate their native soft­-flowing streams.

Water parameters should include a temperature range of 72 to 79 °F (22 to 26 °C), a pH between about 6.0 and 7.0, and soft to moderately hard water. Clean, stable conditions are key for their health.

Feeding Rasbosoma spilocerca is easy. They accept micro pellets or flakes and thrive when given frequent small portions of live or frozen foods such as daphnia, baby brine shrimp, or microworms which help maintain their activity and color.

Dwarf Scissortail Rasboras are peaceful and ideal for nano and community aquariums when kept with other small, calm species like pygmy rasboras, small tetras, Corydoras and dwarf livebearers. Avoid large or aggressive tankmates that may outcompete or stress them.

Breeding is not commonly documented but as with many tiny rasboras they are egg scatterers; eggs are released among fine vegetation or spawning mats, and adults do not guard them. Fry would need tiny foods like infusoria at first.

Rasbosoma spilocerca (Dwarf Scissortail Rasbora) brings subtle elegance, delicate size and continuous schooling motion to well­-planted, soft­-water aquariums.

Photo by Beta Lerdsuwa, cropped from the original, licensed under CC BY-SA 4.0.