粗须白甲鱼的胚胎发育观察

Observation on the Embryonic Development of Onychostoma barbata

为探究粗须白甲鱼人工繁殖技术,本文采用人工催产获得的野生粗须白甲鱼受精卵,对胚胎及胚后发育阶段进行连续观察、拍照和测量。研究结果表明,粗须白甲鱼受精卵近似球形,为具有粘性的沉性卵,卵径(1.99±0.04)mm,吸水后变为(2.84±0.06)mm,受精后开始形成卵间隙,卵间隙形成过程中卵黄收缩、变小。在水温16.5℃~21.7℃条件下,水流控制速度为0.26 m;/h时,粗须白甲鱼从受精卵发育经105.33 h出膜。卵受精后7.73 h进入囊胚期,14.13 h进入原肠期,45.55 h进入器官形成期,73.35 h出现肌肉效应,77.08 h出现心跳,105.33 h完成出膜。本研究根据胚胎发育阶段的形态特征,将其划分为受精卵、胚盘隆起、卵裂、囊胚期、原肠胚期、神经胚期、器官形成期和出膜8个连续发育阶段,总共28个时期。

In order to explore the artificial breeding technology of Onychostoma barbata,and to provide scientific basis for the establishment of its productive seedling technology and management technology,the fertilized eggs were obtained by artificially induced spawning,and the whole processes of embryo and postembryonic development were continuously observed,photographed and measured by using the morphological and ecological research method.The results showed that the fertilized eggs of Onychostoma barbata were nearly spherical in shape and demersal eggs with viscosity.The egg diameter was(1.99±0.04)mm,and bulged to(2.84±0.06)mm after absorption.Just after fertilization,the periphery space of the eggs occurred.Moreover,the yolk sacs shrank and became smaller during the formation of the egg gap.When the incubation water temperature varied from 16.5℃to 21.7℃,and the water flow speed was controlled at 0.26 m~3/h,the membrane of Onychostoma barbata was released after 105.33 h from the normal development of fertilized eggs.After the fertilization,it entered the blastocyst stage at 7.73 h,the gastrual stage at 14.13 h,the organ formation stage at 45.55 h,the muscle effect appeared after 73.35 h,the heart beating occurred at 77.08 h,and the membrane emerged after 105.33 h.According to the morphological characteristics in all stages of the embryonic development processes,it could be divided into 8 stages,i.e.,fertilized egg stage,uplift of blastoderm stage,cleavage stage,blastula stage,gastrula stage,neurula stage,organ formation stage,and hatching stage,with a total of 28 developing phases.