This research was conducted from January to February 2019 at the Laboratory of Fish Hatchery and Breeding at the Faculty of Fisheries and Marine Sciences, University of Riau. This study aims to determine the effect of ovaprim to ovulation and hatching rate of kapiu. The treatment in this study was P0 : injection of NaCL (0,9 %) 0,1ml/kg body weight, P1 : injection of ovaprim 0,5ml/kg body wei…