Artifical Insemination And Growth Rate In Litopenaeus Vannamei

Litopenaeus vannamei has a good cultivation speed since it has been brought into our country. As it has a good compatibility, a strong disease resistance, and growth quickly. At present, Lito-penaeus vannamei which ultimate output reach to 70% and has been became the major cultivation variety in coast and interior include fresh water area of China. However, researches on artificial insemination and growth of L. vannamei too limited to inhibit the development of L. vannamei industry. In the present study, we detected the artificial insemination technique and growth model of L. vannamei to supply referrence for reproduction and culture of L. vannamei.1. Artificial insemination of L. vannameiIn the present study, spermatophore transplantation insemination and sperm suspension insermination were used to check the effect of chasing between male and female L. vannamei on fertilization. The findings showed that fertility rate using artificial semination with spermatophore from natural mating shrimp, spermatophore and sperm suspension from chasing shrimp was 31.59%, 25.16% and 27.82%, respectively. On the other hand, the rate of artificial semination with spermatophore from shrimp without chasing was only 8.48%, whereas the sperm suspension from shrimp without chasing had no fertility.In addition, in the present study, the effect of spermatophore, sperm and egg on fertilization of L. vannamei was detected respectively as well. Results displayed that the spermatophore deposited under normal tempareture within 20 min, sperms deposited in sea water within 15 min and eggs in sea water within 1 min were all highly fertilizable.Finally, the effect of partial spermatophore transplantation on fertilization of L. vannamei was also tested. It was found that partial spermatophore was fertilizable.2. Growth model of L. vannameiAt every monthed of the feeding period, 60 L. vannamei was chosen from 20 lines, then weighted and gauged. The growth model of L. vannamei was then analyzed using three mathmatical models, Logistic, Gompertz and Bertalanffy.The result showed that Gompertz model, with the maximum R2(R2=0.995) among three nonlinear model (Logistic, Gompertz and Bertalanffy), was fitted with the body weight growth of femal and male L. vannamei. And Logistic model was fitted with the body lengtht growth of femal and male L. vannamei (R2=0.991). But the fitting result of body weight and length of femal and male L. vannamei are no significant difference. The body weight growth rate of L. vanname was that fast growing period was starts from 2-month-old and end at 6.8-month-old. The growth peak was 3.9-month-old here the body weight was 6.652g. The body length growth rate of L. vanname was that fast growing period was starts from 1.6-month-old and end at 5.9-month-old. The growth peak was 3.7-month-old here the body length was 5.574cm.In conclusion, we detected the artificial insemination technique and growth model of L. vannamei, suppling referrence for reproduction and culture of L. vannamei.