半滑舌鳎人工催产技术研究

Artificial Propagation of Half-smooth Tongue-sole,Cynoglossus Semilaevis

为了提高半滑舌鳎(Cynoglossus semilaevis)苗种生产的效率,获得批量合格的受精卵,采取控温控光和营养强化培育等措施,使亲鱼性腺全部发育,进行人工催产和人工授精的研究.结果表明多种激素及其激素组合均能有效的对半滑舌鳎进行催产,其中以LRH-A3+DOM的效果较好.在5种催产方案中23℃的效应时间为35-52h,各方案之间差异不显著.人工催产卵的卵径为1.02±0.13mm,明显低于自然产卵的卵径,但受精率、出卵率和孵化率和对照组差异不明显.统计其中10条鱼的催产情况;总浮卵率89.4%,总受精率65.3%,总孵化率为44.8%.共收孵化前卵1060ml,孵化鱼苗约83万尾.

Half-smooth Tongue-sole,Cynoglossus semilaevis,which is the larger species in marine fish,is found in Bo sea and Yellow sea of China. The resources of tongue-sole are declined remarkably because of inordinate catching by men. Therefore,the artificial domestication propagation of tongue-sole are widely developed in the present time. In this paper,the results of propagation for artificial domesticated brood in Half-smooth tongue-sole are reported.In the condition of artificial domestication,it takes 3years for the Half-smooth Tongue-sole to attain gonad maturity and the gonads can be normally developed. Its reproductive cycle is once a year and fastigium is 9-10month in each year. Its ovulation and spermiation can be induced by LHRH-A3 or HCG injection. Individual differences were observed in gonad development within the population. After hormonal injection,it takes 35-52h for female to attain gonad maturity,And LHRH-A3＋DOM can induce female gonad maturity better than other hormones. The reactive time for Half-smooth Tongue-sole spawning is related with different hormone and water temperature. The reactive time of HCG. was longer than LHRH-A3. The lower the water temperature was;the longer time needed. Induced by the extender of LHRH-A and HCG,the reactive time of female was about 35-52h with water temperature is 23.0±0.5℃.The quantity of eggs spawned by 10 female tongue-sole was about 2480ml,with an average of 248. The average of the fertilized rate and hatched rate of these eggs was 65.3% and 44.8% respectively;and about 830000 fry was acquired.