Harlequin Rasbora
About the Harlequin Rasbora in Singapore
Last updated 26 May 2026
.jpg)
What is the Harlequin Rasbora?
The Harlequin Rasbora (Trigonostigma heteromorpha) is a tiny freshwater fish. While it is commonly known in the aquarium trade, its true home in Singapore is incredibly restricted, found almost exclusively within Nee Soon Swamp Forest and the Sime drainages north of MacRitchie.
Identifying features
Check out some identifying features of the Harlequin Rasbora!
The Harlequin Rasbora is easily recognized by its small size, usually growing to a maximum of 5 centimeters, and its beautiful metallic copper, orange, or reddish body. Its most unmistakable feature, however, is the dark black triangular shaped patch covering the back half of its body.
Habitat and ecology
They are schooling fish that require acidic waters to thrive. These are slow-moving, highly acidic swamp streams stained the color of dark tea by decaying leaves and peat.
Did you know?
Instead of just scattering their eggs into the water where they might wash away, the female Harlequin Rasbora swims completely upside down to stick her adhesive eggs directly onto the underside of broad, submerged leaves to keep them hidden and anchored.
Learn more about the Harlequin Rasbora!
Curious about the Harlequin Rasbora? Here are some interesting articles you can read to learn more about them.
