长江鳃胚胎及仔鱼发育研究

以人工繁殖所得受精卵为材料，采用显微照相技术对长江鳡Elopichthys bambusa胚胎及仔鱼发育过程进行观察，并对不同发育时期的形态特征进行了描述和拍照记录。实验结果显示：长江鳡的受精卵为圆球形，卵径为3．5～4．0mm，吸水膨胀后卵径为12．5～14．5mm，为非黏性漂流性卵；胚胎发育可分为胚盘、卵裂、囊胚、原肠、神经胚、器官分化和出膜7个阶段；仔鱼的发育分为卵黄囊期和晚期两个阶段。以长江水为培养用水，水体温度为22—25℃条件下，长江鳡的受精卵历时27h45min孵出仔鱼，其总积温为663℃·h；水体温度为26～29℃条件下，长江鳡仔鱼发育历时30d。

Embryonic and larval development of yellowcheek carp Elopichthys bambusa in the Yangtze River

The embryonic and larval development were observed and described in yellowcheek carp Elopichthys bambus induced to spawn by hormone injection and artificial fertilization under a stereomicroscope. The results showed that the fertilized eggs were spheroid in shape, unsinkable, and unglutinous, and have an average diameter from 3.5 mm to 4.0 mm, 12.5-14.5 mm after expanded in water. The embryonic development can be divided into 7 stages, including blastodisc, cell cleavage, blastula, gastrula, neural stage, organogenesis and hatching, and the larval development can be classified into 2 stages, including yolk period and advanced period. The larvae were hatched 27 hours and 45 minutes after fertilization in Yangtze River at water temperature of 22-25 ℃ ,with total accumulative temperature of 663 ℃ .h. The larval development lasted for 30 days at water temperature of 26-29 ℃.