Preliminary study on artificial insemination techniques for Litopenaeusvannamei

ObjectiveEffective artificial insemination methods for Litopenaeus vannamei were screened out to provide references for the subsequent gynogenetic induction research. MethodWith fertility rate and hatching rate as evaluation in-dexes, the effects of fertilization in vitro spermatophore transplantation and semen transplantation on the breeding efficiency of Litopenaeus vannamei were compared.ResultThe results indicated that no larva was hatched from all treatments in this ex-periment, but relatively high fertility rate (6.67%) could be gained under sperm density of 2×107/L and unfertilized egg density of 300 individual/L within unfertilized egg effluxtime time of 1 min. In semen transplantation method, certain fertilization rate and hatching rate could be obtained with spermatophore at 8℃preservation and insemination operating within 3 h. Fertiliza-tion failed to achieve under more than 3 h. The appropriate spermatophore storage temperature was 8-16℃. Fertilization could not be achieved above 25℃. Among the three kinds of artificial insemination methods, semen transplantation method had the highest fertilization rate and hatching rate, which was 52.33% and 12.35%, respectively. It was followed by spermatophore transplantation method, and vitro fertilization method was the lowest with no nauplius hatched out. ConclusionSemen trans-plantation was the most effective artificial insemination method for Litopenaeus vannamei, and the spermatophore storage time should not exceed 3 h. Spermatophore extrusion and sperm solution release should be performed within 1-2 min after ovulation. Meanwhile the prepared egg collection solution could be added to improve the artificial insemination rate.