In this study, the effects of different light regimes on the reproductive activity of a typical Indo- Pacific coral reef rabbitfish, Siganus sutor, were evaluated. Forty- five adult fish were exposed to nine different photoperiod (8L: 16D, 12L: 12D, 16L: 8D) and light intensity (1000, 2000, 3000 lux) combinations with three replicates and five other fishes reared under indoor light condition (C...