三疣梭子蟹的第二次卵巢发育规律
The Second Ovarian Development of Swimming Crab, Portunus trituberculatus
-
摘要: 2005年3—5月,在室内养殖条件下对第二次卵巢发育的三疣梭子蟹进行连续采样,系统研究了其第二次卵巢发育期间的卵巢指数(GSI)、肝胰腺指数(HSI)、卵巢外部特征、卵巢发育分期及其组织学变化。结果表明:① 三疣梭子蟹第二次卵巢发育过程可以分为4期,Ⅰ期卵巢为乳白色或者淡黄色细带状,卵巢中主要为卵黄合成期的卵母细胞和内源性卵黄合成前卵母细胞;Ⅱ期为淡黄色或橘黄色,主要为外源性卵黄合成期的卵母细胞;Ⅲ期卵巢为橘红色,主要为外源性卵黄合成期的卵母细胞和近成熟期的卵母细胞;Ⅳ期卵巢发育基本成熟,肉眼可见卵粒,主要为成熟期的卵母细胞;② 三疣梭子蟹第二次卵巢发育期间,GSI显著增加,HSI变化不显著,GSI和发育天数呈显著正相关性,HSI和GSI的变化没有显著的相关性。Abstract: During March to May of 2005, mature female swimming crabs were held in captive conditions and fed with fresh clam, Sinonovacula constricta. The spawned crabs were sampled and dissected to investigate the changes to the gonadosomatic index (GSI), hepatosomatic index (HSI), external features of ovary, ovarian histology and its stages during the second ovarian development of Portunus trituberculatus. The results demonstrated that: (1) the process of the second ovarian development could be divided into four stages: stage Ⅰ ovary was ribbonlike and milk white or buff, the main cells in the ovary were endogenous vitellogenic oocytes (EN) and previtellogenic oocytes (PR); stage Ⅱ ovary was buff and orange, the main cells were exogenous vitellogenic oocytes(EX); stage Ⅲ ovary was deep orange, the main cell types were ex and nearly-mature oocytes (NO); stage Ⅳ ovary was ripe, the main cell type was mature oocytes(MO); (2) During the period, the GSI increased significantly, while the HSI did not show a significant difference. A positive correlation could be found between GSI and ovarian development, days after spawning, however there was no significant correlation between GSI and HSI.