This attractive species inhabits clear, acidic, tropical forest streams, where it occurs in small shoals. It is easily identified by the black, triangular patch at the posterior end of the body. In males this patch is more extensive towards the belly and is more clearly defined than in females.

The species is omnivorous, but prefers aquatic invertebrates and small insects. It occurs in many parts of Southeast Asia, reportedly as far east as New Guinea and northern Australia.

The Harlequin Rasbora is also a popular aquarium fish.   

Fig 1 : A small shoal of Harlequin Rasbora in a shallow forest stream, Singapore.

Fig 2 : A pair exhibit courtship behaviour : the male is above. 

Fig 3 : A lone adult of around 3 cm.

 

Family : CYPRINIDAE
Species : Rasbora heteromorpha
Maximum Length : 5 cm

References : F1