Comparative study of reproductive biology Ompok hypopthalmus from the Kampar Kiri and Kampar Kanan Rivers has been conducted on April-May 2018. As there are differences on water condition and water quality in the Kampar Kiri and Kampar Kanan Rivers, the biological aspects of the reproductive of O. hypopthalmus living in those areas might be different. Sixty one fishes (28 males and 33 females) …