人工控制越冬长毛对虾卵巢成熟的初步研究

PRELIMINARY STUDY ON THE OVARIAN MATURATION OF THE ARTIFICIALLY CONTROLLED OVERWINTERING PENAEUS PEN1CILLATUS

本文报道了以人工越冬的长毛对虾Penaeus penicillatus为材料,以切除亲虾单侧眼柄的方法配合适当的生态条件,给予优质的饵料和精心饲养管理,促进亲虾提前成熟产卵,并培育出虾苗。亲虾越冬的存活率为52.91％。手术后亲虾存活率和促熟率分别为65.74％和59.12％。手术后10天即有一尾亲虾促熟产卵,大批成熟产卵是在手术后第25天。产卵后的亲虾经过4—7天的培育又能恢复成熟多次产卵,最多的产4次。从亲虾初次所产的卵径大小、受精率、孵化率及幼体成活率都与海区亲虾相接近,唯有产卵量比海区亲虾少,这是因为人工养殖的越冬亲虾个体小,同时在人工饲养条件下远远不如自然海区的生态条件和营养条件等缘故。越冬期间的水温为13.8—16.5℃,海水比重1.020以上。促进卵巢成熟期间的水温为20.3—27.2℃,海水比重为1.017—1.021。投喂新鲜的贝类、小杂鱼虾,投喂量以第二天略有剩余为度。

This paper presents the result of induced spawning of the artificially controlled overwintering Penaeus penicillatus females by means of uni-eyestalk ablation under 'favored' ecological environment, nigh quality diets and effective management.The survival rate of overwintering parent prawns was 52.91%. The survival rate and maturity after ablation were 65.74% and 59.12%. Ten days after ablation only one female matured and spawned while others did not spawn until 25 days later. After 4-7 days' rearing the spent spawner could remature and spawn again (four times the most). The egg liameter, fertilization and hatching rates and larval survival of the first batch of eggs were similar to those of wild broodstock. The only exception was that the average number of eggs laid per individual was less than that of the wild broodstock, because of the smaller size of the overwintering parent parwns, that were reared under artifically controlled conditions which are considered not quite as natuaral as those in the sea. During overwintering the water temperature (W. T.) was kept at 13.8-16.5℃, the specific gavity (d) 1.020 or so, and during the female maturation, W. T. 20.3 to 27.0℃, d 1.017 to 1.021. Water of the rearing tank was changed one third to one half daily The parent prawns were fed with fresh shellfish and trash fish, and the daily feeding was so regulated as to allow only a bit remnant to be remained on the next day.This experiment can provide scientific basis for carrying out large scale artificial overwintering and inducing maturation so as to mitigate the problem of parent prawn supply.