Sundadanionidae

Sundadanio is a genus of freshwater ray-finned fishes and it is one of two genera in the family Sundadanionidae, known as the tiny danios. These fishes are typically found in peat swamps and blackwater streams, in Borneo and Sumatra (as well as nearby smaller islands) in southeast Asia. At up to in standard length they are very small, but still larger than their close relatives Paedocypris. Species of the two genera are often found together.