额尔齐斯河黑鲫胚胎及早期仔鱼发育特征OA北大核心CSTPCD

This study was conducted to understand embryonic and larval development of Carassius carassius distributed in the Irtysh River Basin,fill the gap in artificial breeding,and enrich the reproductive biological data of this species.This study collected C.carassius parents from the Irtysh River,obtained fertilized eggs through artificial induction of fertilization,and observed their early developmental characteristics.The results showed that the embryos hatched out of the membrane at a temperature of(19.89±0.64)℃ for 110 h and 35 min,and a total accumulated temperature of 2274.54 h·℃.The C.carassius embryo started from the fertilized egg,placenta was bulged 50 min after fertilization and developed to a blastocyst in 6 h 40 min.The gastrul embryo developed in 17 h 20 min,nerve developed in 26 h 20 min,sarcomere appeared in 37 h 20 min,heartbeat occurred in 70 h 35 min,and membrane emerged in 110 h 35 min.The embryonic development process went through seven stages(26 periods)of fertilized egg,cleavage,blastocyst,gastrulation,neural embryo,organ formation,and hatching.Lying at the bottom,the total length of the fry hatched after 1 d was(4.45±0.12)mm,and the yolk sac was full;the full length of the fry after 2 d was(5.13±0.18)mm,the pigmentation had increased,and a short swim was observed;the total length of the fry after 3 d was(5.69±0.17)mm,they were sensitive to external stimuli,the yolk sac was absorbed,and anal and caudal fins were clearly visible.This study is the first to report the timing and characteristics of the early development of the Irtysh River C.carassius under artificial induction conditions,thereby providing basic data and an important reference for further large-scale breeding of seedlings.