ABSTRACT This research was conducted on April - May 2021, at Fish Hatchery and Breeding Laboratory of Fishery and Marine Science Faculty of Riau University. The aim of this research was to determine the effect of Kirinyuh leaf (Euphatorium odoratum) solvent and the optimal dose on hatching rate of tambaqui larvae (Colossoma macropomum). The method used was a Completely Randomized Design Factor…