REPRODUCTIVE PERFORMANCES OF WILD BLACK TIGER SHRIMP,PenaeusmonodonINSEMINATED WITH DIFFERENT SOURCES AND NUMBERS OF SPERMATOPHORE  

One of themain constraints in the domestication ofblack tiger shrimpisthe verylow naturalmatingin the captive.Similar condition happened in commercial hatcheries indicatedby  declining of  hatching rate at the further spawning due to the lower  number offertilizedeggs. Infertiled eggs could be caused by the failure of fertilization or unsuccesfull mating which means no spermatophore transferred to female thelycum. One effort toimprove theeggs fertility isthrough artificial insemination (AI). This study aimed toevaluate thereproductive performanceof wild blacktiger shrimp after inseminationwith  differentsources and numbers of spermatophore.

This studyconsistedoftwo trials, the firstwasAIusingspermatophoresof wild male obtained from two different locations fromSouthSulawesi(SS) andAceh(SA). Weight of the femaleused ranged from 95 to 113g, stocked with 16  female/treatment. The second trial wasAIusing differentnumbers ofspermatophorenamely1spermatophore(S1) and2spermatophore (S2). Weight of the female  inseminatedwas in the rangeof 105-110gand stocked at 10 female/treatment. Spawners were maintainedin two of 10tonnages concrete tanks.To release thespermatophoreout of ampulla terminal, the males were electrically shocked using aelectricaltransformerat 15 volt/7mA provided by twoelectrodes. Bothelectrodes were places near the gonophores at the base of the fifth preopodfor about30-60seconds.AI was applied  to the females at two dayspost-moulting. Variablesobserved were the number of spawn, fecundity, fertiledeggs,eggdiameter andhatching rate (HR).

The results of the firsttrial showed that theHR was notaffected bythe sourceof themale which was61.6% for SSand61.7% for SA. The secondtrial indicated that female inseminatedS2 had lower HR thanS1(39% vs48%). It was suspected that several spermatophores inseminated in S2 group released from thelycum because they might be not in the proper   positionwithin the thelycum. AI with2spermatophoresrequiresa better techniquesin implantation to keep the spermatophores inside the thelycumuntil spawning occured.