Puntius hexazona (Sumatra fish) is a type of freshwater fish that inhabits the streams in the Riau University area and the upstream of the Sibam River. A study aims to understand the reproductive biology of P. hexazona has been conducted from May-August 2019. The fish was sampled 6 times, twice/month. Parameters measured were sexual characteristics, sex ratio, gonad maturity level, gonad somati…