ABSTRACT Rasbora caudimaculata is a type of freshwater fish that commonly inhabit the Teluk Petai Lake and Tanjung Kudu Lake, Kampar Regency, Riau Province. This study aims to understand the reproductive biology of R. caudimaculata . The fish was sampled 4 times, once/week, from November–December 2020. Parameters measured were sexsual characteristics, sex ratio, gonad maturity level, gonad s…