Rasbora Heteromorpha, sometimes called the Harlequin Rasbora, is a lively, excellent community and planted tank fish.  These fish typically occupy the upper third of a tank.  My Rasbora sometimes play in the current generated by the filter return.  They are colorful, playful, and hearty fish.  These fish like very soft, very acidic water and temperatures of between 75 and 81 degrees Fahrenheit, but will do well in more alkaline and harder water.  (They breed in waters of 1 to 2 degrees of hardness with a PH significantly  below 6.0.)  These fish are best kept in a school of at least six.  They have a very similar looking cousin, Rasbora hengili, that does not have as prominent a triangular black spot, though appear very similar in every other respect.  R. heteromorpha and R. hengeli are both native to Indonesia, Sumatra, and Thailand.  They are typically found in schools inhabiting marshy pools, mountain rivulets, and densely shaded overgrown streams.  They will eat flake food, frozen brine shrimp, blood worms and just about anything else that they are offered.