Siamese Dwarf Rasbora Care Guide
Trigonostigma somphongsi · Freshwater Fish
What Siamese Dwarf Rasbora look like
The Siamese Dwarf Rasbora (Trigonostigma somphongsi) is a diminutive, laterally compressed cyprinid, reaching a maximum adult size of approximately 2 inches (5 cm). This species exhibits sexual dimorphism, with males typically displaying a more vibrant coloration and slightly more pronounced wedge-shaped markings compared to females. The body is characterized by a golden hue, adorned with a distinctive dark triangular or wedge-shaped marking that extends from the dorsal region towards the caudal peduncle. The fins are generally transparent with a subtle hint of yellow, and the species features a small adipose fin, which is typical in the family Cyprinidae. Defensive adaptations include its small size and schooling behavior, which help reduce predation risk. The lateral line system is well-developed, aiding in the detection of water movements, which is crucial for its survival in the wild.
Behavior & temperament
Siamese Dwarf Rasboras are typically found in small, tight-knit schools, exhibiting social behaviors that reflect a hierarchical structure, with dominant individuals often leading the group. They dwell primarily in the mid to upper water column of their natural habitats, which consist of slow-moving streams and shallow waters in Southeast Asia. Breeding behavior is characterized by egg scattering, where females release eggs among vegetation, and males fertilize them externally. This species is generally peaceful and exhibits low aggression levels, making it an ideal candidate for community tanks, although they may display territoriality during breeding.
Diet & feeding
In the wild, the Siamese Dwarf Rasbora is an omnivore, feeding on small invertebrates, algae, and detritus. In captivity, they thrive on a varied diet that includes high-quality flake food, micro-pellets, and live or frozen foods such as daphnia and brine shrimp to ensure optimal health and coloration.
Behind the name
Trigonostigma (triangular mark); somphongsi (named after the Thai ichthyologist who described the species).
Plan your tank
Check the numbers before you buy: tank volume, a stocking plan, cycle progress, water changes, and your ongoing care routine.
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