HORMONE-INDUCED MULTIPLE SPAWNING OF CAPTIVE NASSAU GROUPER BROODSTOCK

During a 5-month period from 3 December 1991 to 28 April 1992, two fem ale Nassau grouper Epinephelus striatus were spawned three rimes and o ne female two times by hormone induction. The interval between spawnin gs for an individual female ranged from 28-75 d. Successful spawnings (fertilization rate > 50%) were induced in females with average oocyte diameters ranging from 517-544 mu m by a primary injection of human c horionic gonadotropin (HCG; 1,000 IU/kg body weight), followed by a se cond injection (500 IU/kg body weight) after 24 h. Time of strip-spawn ing ranged from 37-45 h after the first injection and was inversely re lated to average water temperature (range, 22.4-26.4 degrees C). Mean diameters spawned eggs were 871-959 mu m, and the number of eggs spawn ed per female ranged from 200,000 to 2,000,000. Fertilization and hatc hing success were 17.9-80.6% and 68.3-90.1%, respectively. The results demonstrate a reproductive capacity that minimizes broodstock require ments and enhances suitability of the Nassau grouper for aquaculture.