1. During the first normal mating process, spermatophores are -stored in the thelycum of the female shrimp. Subsequent mating may result in successful or unsuccessful abnormal mating depending on whether the spermatophores of the male shrimp are inserted in certain parts of the female shrimp body other than the thelycum, or are not deposited at all after the mating process.

2. Based on the external appearance of the remains of the thelycum of normally mated females, it is here suggested that abnormal mating may follow normal mating. During the normal mating process, spermatophores are stored in the female of the thelycum. Out of protection for its spermatophores, the normally mated female shrimp refused the subequent mating and so resulted in abnormal mating.

3. Abnormal mating can result in loss of the male spermatophores and damage of the female shrimp body and finally cause a decline in quality and quantity of parent shrimp stocks. Abnormal mating is a harmful phenomenon and preventive measures should be taken. In artificial overwintering culture during the mating season of the parent shrimps, once the female shrimps have been mated, they should be picked out in due time and reared separately to prevent their mating again. During the early stage of overwintering culture, when the water temperature is high, it is best not to place male shrimps in the same pond With mated female shrimps.