长丰鲢胚胎发育的初步观察

Observation on the embryonic development of Changfeng silver carp

在(24±1)℃温度条件下观察长丰鲢(Changfeng silver carp)受精卵发育过程及其胚胎发育各个时期的形态特征。结果显示:长丰鲢受精卵为漂流性卵(半浮性卵),无油球,细胞质均匀分布,卵径为(1.55±0.05)mm,吸水后卵膜膨大,卵径达到(5.10±0.40)mm。在水温(24±1)℃的条件下,胚胎发育总历时为(28.5±1.0)h,胚胎发育过程所需总积温为(685.0±62.3)℃獉h。长丰鲢受精卵卵裂方式与其他家鱼一样,属于盘状卵裂,本文依据胚胎发育各阶段的形态特征,将其划分为7个连续发育的关键阶段,18个不同的时期,分别为受精卵期、卵裂期、囊胚期、原肠胚期、神经胚期、器官发生期和出膜期。

The embryonic development characteristics of Changfeng silver carp were studied at the water temperature（ 24 ± 1） ℃. The results showed that the fully mature eggs were spherical, semi- floating and（ 1. 55 ± 0. 05） mm in diameter. After water absorption,the egg membrane swelled,the average egg diameter was（ 5. 10 ± 0. 40） mm and without oil globule. It took（ 28. 5 ± 1. 0） h from fertilization to hatching- out with the average accumulative temperature of（ 685. 0 ± 62. 3） ℃ ·h. The cleavage of fertilized eggs of Changfeng silver carp has belonged to discoidal cleavage. The embryonic development process could be divided into 7 stages,including fertilized egg stage,cell division stage,blastula stage,gastrula stage,neurula stage,organ formation stage and hatching stage. They contained eighteen developing phases,whose characteristics were described in detail.