团头鲂的胚胎发育与观察方法优化

通过人工繁殖获得团头鲂受精卵,在体视显微镜下对其胚胎和早期仔鱼发育过程进行了连续观察、拍照与测量.结果显示,团头鲂受精卵呈圆球形,具黏性,卵径(1.18±0.09)mm;在水温(21±1)℃条件下,团头鲂胚胎发育从受精到孵化历时39h10min,经历了胚盘形成、卵裂期、囊胚期、原肠胚期、神经胚期、器官形成期和出膜期7个发育阶段;初孵仔鱼体长(3.44±0.29)mm,出膜后第4d仔鱼鳔完全充气,卵黄囊消失;观察时,受精卵至尾鳍出现期胚胎置0.7%生理盐水中,肌肉效应期和后面各时期的胚胎经4%多聚甲醛固定后置3%甲基纤维素中拍照可获得良好效果.该工作为研究团头鲂胚胎早期发育过程提供了实时和动态的图像资料,并为鱼类胚胎发育观察提供了基本技术参考.

Embryonic development of Megalobrama amblycephala and optimization on the observation method

This study investigated the development process of embryos and early larval fish from Megalobrama amblycephala under stereoscopic microscope.The fertilized eggs were sticky and round with a diameter at(1.18 ± 0.09)mm.The embryonic development underwent seven stages as blastoderm formation,cleavage,blastula,gastrula,neurula,organ formation and hatching stage.Under incubation temperature of(21±1)℃,the embryos take 39 h10 min to hatch into larvae,which is near(3.44±0.29)mm in length.The swim bladder of the larvae was inflated completely and the yolk sac disappeared in the fourth day.An optimized protocol was obtained to achieve the better observation:Embryos before muscle functioning stage were treated with 0.7% saline,or embryos after muscle functioning stage were fixed in 4% PFA and immersed into methylellulose.Taken together,the present study provided dynamic images on the embryonic development of M.amblycephala and supplied a basic technical skill on observation of fish embryos.