南美洲白对虾全人工授精技术研究

STUDIES ON THE FULL-ARTIFICIAL FERTILIZATION OF PEN AEUS VANN AMEI

于1988年4月和1991年4月分别从厄瓜多尔和美国引进南美洲白对虾仔虾,经驯化、养成和室内人工越冬后,采用单侧眼柄切除手术人工催熟,以试管授精和人工植荚方法进行该种的繁殖技术试验。结果表明,(1)体长在13—16cm的南美洲白对虾雌虾,一般在摘眼后的1—2周内开始性腺发育;产卵量通常为3—10万粒;产卵后的雌虾卵巢可再次发育,最高产卵次数高达19次。(2)应用高频电针法取荚的成功率和取荚后雄虾的存活率均为100％;用上述方法取得的精荚内的精子无需“获能”即可使卵子受精。(3)假裂现象在南美洲白对虾的未受精卵中较为普遍。

In this study, conducted from April, 1988 to August, 1992, three groups of P. vannamei postlarvae were achieved successfully using full-artificial fertilization technique. The parent shrimps used in tests were introduced from Ecuador and the United States in 1988 and 1992 respectively and grew up in fabric tanks. The fertilization rate of eggs was 2 to 22 percent.In 27-30℃, health female shrimp of P. vannamei, 13-16 cm in body length, began to. mature and spawn about 1-2 weeks late after unilateral eyestalk ablation. The number (from 30 000 to 100 000) of eggs per spawning for one female shrimp ranged, closely related to its size. The spawner could mature and spawn again within 3-5 days, with a minimum of 48 h only. It was recorded that a female shrimp matured and spawned up to 17 times in this study. In general, a female shrimp was accompanied by moulting after 3-5 times of successive spawning.Spermatophore was obtained using electric acupuncture. Both the rate of spermatophoreobtaining and the survival of male shrimp were 100%. The sperm obtained directely from ampoules of male shrimp was functionally ripe, i.e. it was capable of fertilizing oocytes without ca-pacitation in thelycum of female shrimp.The size of the 1st maturation of ovary developing restricts the following size of successive maturation.It was common for non-fertilized eggs of P. vannamei to undergo pseudo-cleavage about 2-3 h late after spawning. Just the same as fertilized eggs, non-fertilized eggs began to exocytose its cortical rod to form the egg jelly soon after spawning into seawater and then release the first and second polar body and elevate the 'fertilization membrane'.