为了解鲤科经济鱼类马口鱼(Opsariichthys bidens)胚胎及仔稚鱼发育特点,采用人工干法授精获得受精卵,在人工孵化及培育条件下观察了马口鱼胚胎发育及仔稚鱼的形态变化与生长特性.马口鱼成熟卵及受精卵均呈圆形、沉性,卵径分别为1.00-1.20mm及1.4-1.6mm.在26-28℃水温下,胚胎发育历时37h,历经了胚盘形成期、卵裂期、囊胚期、原肠胚期、神经胚期、器官发生期、心跳期和孵出期等阶段,所需积温为968.95℃.h.初孵仔鱼全长3.74±0.04mm.在26-28℃水温下,仔鱼孵后12h,胸鳍原基形成;孵后48h,肠道形成;孵后84h,一鳔室形成;孵后96h,多数开始平游;孵后108h,卵黄囊消失,早期仔鱼发育至后期仔鱼,营外源性营养;孵后14d,两鳔室形成;孵后17d,全长12.46±0.76mm,各鳍发育完整,鳞片开始出现,进入稚鱼期;孵后23d,全长达17.09±1.08mm,外部形态特征与成鱼相近.马口鱼仔稚鱼生长方程显示异速生长特性.本研究积累了马口鱼早期生活史资料,为马口鱼人工繁殖及鱼苗培育提供理论参考.%In order to reveal the developmental process and characteristics of embryo,larva and juvenile of Opsariichthys bidens,we obtained fertilized eggs by dry artificial fertilization method.Then the process of development had been observed carefully under artificial rearing conditions after artificial hatching.The results showed that the mature egg (1.00-1.20mm in diameter) and fertilized egg (1.4-l.6mm in diameter) of O.bidens are demersal and in shape of spherical.The hatching of fertilized eggs took 37h at 26-28℃C,and the embryonic developmental stages of O.bidens could be divided into blastoderm stage,cleavage stage,blastula stage,gastrula stage,neurula stage,organogenesis stage,heart beating stage and hatching stage.The total accumulative temperature is 968.95℃C.h and the lengths of newly hatch-out larvaes were (3.74±0.04)mm.When the water temperature was 26-28℃C,pectoral fin formed on 12HAH (hour after hatching).What's more,the formations of intestines have been observed on 48HAH.One-chamber air bladder and formed on the 84HAH;to mostly larva fish of O.bidens,the behaviour of horizontal swimming could be observed on 96HAH.As the sign of the late larvae stage,the larva exhausted all the yolk sac and entered the stage of exogenous feeding on 108HAH.Two-chamber air bladder formed on 14DAH (day after hatching).Fin rays were formed on 17DAH,the formation of scales occurred at the same time which means the larvae reached the juvenile stage.The total lengths of juvenile were (12.46±0.76)mm.Juvenile fish grew up to fingerling fish on 23DAH,the total lengths of fingerling were (17.09±1.08)mm and there was no difference in the morphological feature between fingerling fish and adult fish.Statistic analysis showed that the growth of O.bidens was allometric.This study provided theoretical basis for further development of artificial reproduction and fry culture of O.bidens.
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