THE STUDY OF EYE STALK EXCISION OF MONODON TO INDUCE ITS MATURITY AND SPAWNING
摘除眼柄诱导斑节对虾成熟产卵的研究

The excision of Monodon's eye stalk (Left or right eye) does induce its maturity and spawning. It also leads to high survial rate without affecting its normal eating and mating activity. No adverse effect was found if their eye stalk (right or left) or eyes are takan off. Excision of Monodon's eye stalk plays an important part in inducing its maturity and spawning. Best results were obtained in the following experimental conditions. The prawn will reach the peak of maturity within 15 to 35 days after eye stalk excision. This experiment showed that the rate of acceleration of ripening is 57.4%(highest can be 100%); average fertilization rate is 59%(highest is 88.9%); number of eggs produced generally depends on prawn's size(the bigger the prawn, the larger amount of eggs it will lay). Usually 2 to 4 hundred thousand eggs 10 to 30% less than the natural mature prawn. The average hatch rate is 72.3%, maximum 97.1%. Prawns with excision of eye stalk may apawn 2 to 3 times the maximun 5 times, but moult easily so that they lose spermalophores when environment is not stable.