2013年5月，对水库网箱养殖的3足龄美洲鲥亲鱼进行催产，通过半干法人工授精获得受精卵。连续观察美洲鲥从受精卵到初孵仔鱼29个发育期的发育时序及形态特征，结果显示：美洲鲥胚胎发育可以分为卵裂前期、卵裂期、囊胚期、原肠胚期、神经胚期、器官形成期、孵化出膜期等7个阶段；美洲鲥的受精卵卵膜透明，无粘性，无油球，卵径为（3．15±0．15）mm，卵周隙为0．8 mm；在孵化水温（21．5±0．5）℃条件下，受精后30 min，胚盘形成；50 min，进入卵裂期；5 h 10 min，进入囊胚期；12 h，进入原肠期；16 h，进入神经胚期；受精后24 h 10 min，进入器官形成期；59 h 50 min，进入孵化出膜期；66 h 30 min后，开始出膜。鲥鱼受精卵完成胚胎发育所需积温为1463（℃·h）；初孵仔鱼全长6．9～7．1 mm，体透明。本研究为美洲鲥的人工繁殖提供理论指导。%Fertilized eggs were obtained from cage-culturedAlosa sapidissima by half dry artifical fertiliza⁃tion in May 2013.The developmental time and morphological characters of 29 embryonic developmental stages were observed using microscope from fertilization to hatching. The results showed that the embryonic develop⁃ment of Alosa sapidissima could be divided into 7 stages,including the one-cell stage,cleavage stage,blastula stage,gastrula stage,neural stage,organogenesis stage and the hatching stage according to the morphological features.The fertilized eggs of Alosa sapidissima were transparent without stickiness and oil globule;the egg di⁃ameter was 3.15±0.15 mm;the egg gap was 0.8 mm.Under the water temperature (21.5±0.5)℃,30 minutes after fertilizing,the fertilized eggs developed to the formation of blastoderm,50 minutes to the cleavage stage, 5hours and 10 minutes to the blastula stage,12 hours to the gastrula stage,16 hours to the neurula stage, 24hours and 10 minutes to the organogenesis stage,59 hours and 50 minutes to the hatching stage,and 66 hours and 30 minutes,fries began to hatch out.Under the water temperature (21.5±0.5)℃,the total effective accumulated temperature for the embryonic development of Alosa sapidissima was 1 463 (℃· h ) . The total length of the newly hatched larvae was (3.15±0.15)mm and the larvae were transparent.This study might pro⁃vide theoretical guidance for artificial propagation of Alosa sapidissima.
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