ROLE OF HORMONAL INDUCTION FOR GONAD DEVELOPMENT OF POTATO GROUPER BROODSTOCK Epinephelus tukula
A collection of potato grouper broodstock (Epinephelus tukula) has been able to be confined in controlled tanks since 2010, however the female could not spawn naturally and sperm maturation in the male could not be optimal. Based on that results, hormonal inductions using LHRH-a and 17α methiltestosterone were performed to optimize spawning and sperm maturation, respectively.
Broodstock of potato grouper (n = 38) body weight 16.47 + 2.43 kg was kept in two concrete tanks with a capacity of 100 m3 in a flow through system with water exchange 250 - 300% per day. Fish were fed fresh fish and squid once per day ad libithum (2 - 5% biomass per day). Induction hormone LHRH-a was conducted on the female with a dose of 50 µg/kg body weight and induction hormone 17α methiltestosterone was conducted on the male with a dose of 1000 µg/kg body weight.
The result showed that gonad development in those induced with hormone LHRH-a and 17α methiltestosterone was significantly different (P value < 0,05) from control treatment and the probabilities that the number of broodstock developed being female was 1,4X higher in control treatment and the number of broodstock developed being male was 8,9X higher in 17α methiltestosterone treatment. Oocyte diameter in induction hormone LHRH-a was significantly different (P value < 0,05) from control treatment and the probability the control treatment had large oocyte was 1,17X higher than others. Meanwhile, development of oocyte maturity level in induction hormone LHRH-a was not significantly different (P value > 0,05) from control treatment. Sperm maturation in induction hormone 17α methiltestosterone had not give significant result indicated from the motility which was 90,9% static and 9,1% unprogressive, and the velocity which was VCL =