中华花鳅胚胎及胚后发育的研究

Embryo Development and Post Embryonic Development of Cobitis sinensis

通过人工授精获得中华花鳅(Cobitis sinensis)受精卵,利用显微镜对其胚胎及胚后发育进行连续观察,并用数码相机拍照记录。结果显示:中华花鳅的卵为圆球形,卵质均匀呈金黄色,具有微粘性,刚产出时,卵径约为0.95 mm,在水温25.7~27.1℃的情况下,胚胎发育历时约25 h 30 min,共分为6个阶段:受精卵阶段、卵裂和囊胚阶段、原肠胚阶段、神经胚阶段、器官形成阶段和出膜阶段。胚后发育分为仔鱼期、稚鱼期和幼鱼期共3个时期。其中,仔鱼期分为仔鱼前期和仔鱼后期,在水温24.1~26.7℃的情况下,仔鱼前期从仔鱼出膜到卵黄囊吸收消失历时3 d,仔鱼后期从卵黄囊吸收消失到外鳃消失历时2.5 d;稚鱼期从内鳃形成到外部形态发育完善历时34.5 d;幼鱼期从外部形态发育完善到第一次性成熟历时2年。

In this study,fertilized eggs of Cobitis sinensis are obtained by artificial insemination and the embryos and post-embryonic development are continuously observed by a microscope and recorded by digital cameras.The results show that the eggs of C.sinensis are round and slightly viscous,with uniform egg plasm in golden yellow;the diameter of the eggs is around 0.95 mm when they are laid out.The embryonic development lasts about 25 h 30 min when the water temperature is 25.7~27.1 ℃.It is divided into six stages:fertilized egg stage,cleavage and blastocyst stage,gastrula stage,neuroembryo stage,organ formation stage and hatching stage.Post-embryonic development is divided into three stages:larval stage,juvenile stage and young stage.The larval stage is further divided into pre-larval stage and late-larval stage.When the water temperature is between 24.1 ℃ and 26.7 ℃,it takes 3 days from hatching to yolk sac absorption in the pre-larval stage,and another 2.5 days for the outer gill to disappear in the late-larval stage.The juvenile stage takes 34.5 days from the formation of the inner gills to the complete development of external morphology,and the young stage takes another 2 years to reach sexual maturity.