Dwarf rasbora
The dwarf rasbora is a species of ray-finned fish in the genus Boraras, native to freshwater habitats of southeast Asia. It grows to be about 10–20mm long at adulthood, the maximum length can reach 25mm. Dwarf Rasbora are shoaling fish which means they are always in groups of 8 fish or more. They are very peaceful species that don't harm anyone or anything.