中华绒螯蟹生殖蜕壳后卵巢发育规律的研究

Ovarian Development of Chinese Mitten Crab Eriocheir sinensis after Genital Molting

在水温19.2~28.5℃下,将生殖蜕壳前体质量为50~70 g的中华绒螯蟹雌蟹养殖在室内2.5 m×3.75 m×1.0 m聚乙烯水桶中,桶中放聚氯乙烯板和水草等遮蔽物。当试验蟹生殖蜕壳硬化后,取出30只雌体继续养殖60 d,每5~10 d随机解剖3只,称量卵巢质量和体质量,同时取少量卵巢组织固定于波恩氏液中,做组织学观察。共解剖6次,以研究养殖条件下群体的生殖蜕壳后的成活率、质量增加率和卵巢发育规律的变化。试验结果表明,中华绒螯蟹雌体生殖蜕壳后的平均成活率和质量增加率分别为(71.11±3.85)%和(54.60±4.93)%;生殖蜕壳后20 d内雌体卵巢发育较为缓慢,随后卵巢进入快速发育阶段,生殖蜕壳后60 d时,雌体的平均卵巢指数为(7.43±0.23)%;生殖蜕壳后雌体的卵母细胞长径随着卵巢的发育持续增加,待生殖蜕壳后60 d时,雌体卵母细胞的长径可高达280μm;雌体卵巢组织学变化主要发生在生殖蜕壳后20~50 d,主要变化为由内源性卵黄发生期卵母细胞发育为近成熟期卵母细胞,平均卵巢指数由(1.48±0.09)%增加至(6.83±0.51)%。

Female Chinese mitten crab Eriocheir sinensis with body weight of 50—70 g was reared in a 2.5 m×3.75 m×1.0 m PE bucket with PVC boards and aquatic grass at water temperature of 19.2—28.5℃.When the Chinese mitten crab was molted for reproduction,30 female individuals were still cultured for 60 days,and 3 samples were dissected at random every 5—10 d to measure ovarian weight and body weight and to sample a small amount of ovarian tissue which was fixed in Bouin′s solution for histological observation in order to evaluate the survival rate,weight gain rate and ovarian development pattern.The mean survival rate was found to be(71.11±3.85)%and weight gain rate to be(54.60±4.93)%in the female Chinese mitten crab molted for reproduction.The ovary was shown to be developed slowly within the first 20 days,and then entered the rapid development stage,with mean gonadosomatic index of(7.43±0.23)%in 60 days.The female Chinese mitten crab had oocytes with increasing diameter as the development of ovary,with the long diameter of 280μm in 60 days.The major histological changes in the ovary were observed in the female from 20 days to 50 days,the transition from the endogenous yolk oocyte to the near-mature oocyte,with increase in gonadosomatic index from(1.48±0.09)%to(6.83±0.51)%.