Wild-caught mangrove red snapper (Lutjanus argentimaculatus) were reared in a floting net cage at SEAFDEC/AQD's Igang Marine Substation at Guimaras Island, Central Philippines. In 1993, monthly sampling and induced spawning trail were conducted as paert of aproject on seed prodection. Gonadal development beganin February or males and Apirl for females, reached a peak in September and declined in December. Males and females had ripe gonads for to 5-6 consecutive months. Spawning accurred in the evening (2000-2300 hours), 32-36 hours after a single intramuscular injection of 1 500 IU human chorionic gonadotropin kg ^-1 body weight (BW). About 0.53-2.14 million eggs were collected per female (2.5-4.4 kg BW) with fertilization rate of 21-97% and hatching rates of 42-80% resulting in 30-85% normal larve (straight and without defomities). The results strongly suggest the feasibility ofbreeding mangrove red snapper in floating cages.