Hormone-Induced Multiple Spawning of Captive Nassau Grouper Broodstock

Abstract

Abstract During a 5-month period from 3 December 1991 to 28 April 1992, two female Nassau grouper Epinephelus striatus were spawned three times and one female two times by hormone induction. The interval between spawnings 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 μm by a primary injection of human chorionic gonadotropin (HCG; 1,000 IU/ kg body weight), followed by a second injection (500 IU!kg body weight) after 24 h. Time of strip-spawning ranged from 37–45 h after the first injection and was inversely related to average water temperature (range, 22.4–26.4°C). Mean diameters spawned eggs were 871–959 μm, and the number of eggs spawned per female ranged from 200,000 to 2,000,000. Fertilization and hatching success were 17.9–80.6% and 68.3–90.1 %, respectively. The results demonstrate a reproductive capacity that minimizes broodstock requirements and enhances suitability of the Nas...