INJECTION OF OOCITE DEVELOPER ENHANCED GONADAL MATURATION OF WILD MALE TIGER SHRIMP, Penaeus monodon AGAINST EYE STALK ABLATION
Hormonal manipulation in crutaceans has been reported as an alternative technique to improve their reproductive performance. This experiment was conducted to evaluate the oocite developer to induce the gonadal maturation of wild male tiger shrimp, Penaeus monodon against eye stalk ablation.
Oocite developer (OD) used in the experiment is a hormone premix containing pregnant mare serum gonadotropin and antidopamin. Two dosages of OD were evaluated at 0.5 (OD0.5) and 1.0 (OD1) mL/kg and control was eyed stalk ablation (AB). The OD was administered via injection two times with one week interval. The 75 wild male broodstocks were randomly distributed into three of 10 tonnages concrete tanks with density of 25 shrimps per tank. A week after the last injection, males were electrically shocked to release their spermatophores from ampula terminalis. Variables observed were male reproductive performance and profiles of fatty acid of muscle of the male stocks.
Males injected with OD0.5 produced the highest number of spermatophores which was 80.8% followed by AB (68%) and OD1 (64%). Injection of OD shortened the time for maturation where all males injected with OD0.5 released their spermatophores within 7-d while AB matured until 21-d. Characteristic of spermatophore including weight of spermatophore and number of sperm cell did not differ (P>0.05) among treatments. There was a positive correlation between weight of male and spermatophore weight where R2 value was high at OD0.5 (0.60) and when all data was pooled (0.61).
Total fatty acid contents (%) in muscle of male induced with OD0.5 and OD1 were 2.64 and 2.65, respectively higher than those of ablated male. 2.26.
Based on number of matured males and several other parameters, the optimum dose of OD to enhance the reproductive performances of male tiger shrimp was 0.5 mL/kg.