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以人工繁殖所得的仔鱼为材料,观察了厚颌鲂胚后发育过程,对各个发育期的形态特征进行了描述。结果表明,厚颌鲂胚后发育过程可划分为2个阶段16个时期。初孵仔鱼平均全长(4.78±1.12)mm,肌节数43对。孵出后115.5h卵黄吸尽,仔鱼完全依赖于外源性营养,进入晚期仔鱼阶段,此时仔鱼全长(7.11±0.90)mm。发育至47d时开始出现鳞片,标志着进入了幼鱼阶段,此时全长(19.75±3.71)mm。在22.2~25.0℃条件下经过68d的发育,全长(31.82±3.87)mm的鱼苗,鳞片出齐,基本具备成鱼特征。在胚后发育过程中,鱼体长度生长、鱼体长度性状间的比例关系并不相同,其中,孵出期的生长速度最大;肛后长/全长比例随胚后发育逐渐增加,最后稳定在45%左右;体长/体高比值逐渐减小,并逐渐与成鱼的比例接近。
The artificial larvae were used as materials to observe the post-embryonic development of Megalobrama nobilis and the morphological characteristics of each stage were described. The results showed that the process of post-embryo development can be divided into two stages and 16 stages. The average length of newly hatched larvae was (4.78 ± 1.12) mm, with 43 pairs of sarcomeres. 115.5h after hatching egg yolk exhaustion, larvae completely dependent on exogenous nutrients into late larval stage, at this time the full length of larvae (7.11 ± 0.90) mm. Scales started to develop at 47 days, marking the entry into the juvenile stage with a full length (19.75 ± 3.71) mm. Under the condition of 22.2 ~ 25.0 ℃ for 68 days, the fry with the full length (31.82 ± 3.87) mm and scales had the same appearance and basically had the characteristics of adult fish. During the post-embryonic development, the relationship between the length growth of fish body and the length of fish body was not the same. Among them, the growth rate was the largest at hatching stage; the ratio of length of anus to full length increased gradually with embryo development and finally stabilized At about 45%; body length / height ratio gradually decreased, and gradually with the adult fish close to the ratio.