鲻仔、稚鱼的发育及生长特点

Characteristics of development and growth of larva and juvenile in Mugil cephalus

对人工培育的1～43日龄的鲻各发育阶段的形态特征进行了观察和描述.根据卵黄囊、鳍和鳞片的变化,将鲻的胚后发育划分为仔育期、稚鱼期和幼鱼期3个时期.初孵仔鱼平均全长2.4421 mm,在水温19.94（±1.03）℃、盐度30、pH 8.10～8.15的条件下,初孵仔鱼至10日龄为早期仔鱼,4日龄仔鱼开口,孵化后11～26日龄为后期仔鱼,孵化后27～38日龄为稚鱼,孵化后39日龄进入幼鱼期.并研究了鲻胚后发育的生长特点,结果发现鲻仔稚鱼属于均匀生长类型.此外,还探讨了鲻胚后发育过程中的危险期,以及生长发育与生活习性之间的联系.

The morphological characteristics at early development stages were observed and described in hatcheryproduced Mugil cephalus from newly hatched larvae to 43 d after hatching. The post embryonic development of M. cephalus was divided into larval stage,juvenile stage and young fish stage,based on the features of yolk-sac,fins and scales. Under the water temperature of 19.94（±1.03）℃,salinity of 30,and p H 8.10-8.15,it took 10 days from newly-hatched larvae stage to prelarva stage. The mouth of larva opened 4 days after hatching. From 11 d to 26 d after hatching,the fish developed into postlarva stage. From 27 d to 38 d after hatching,the fish developed into juvenile stage,and entered to young fish stage in 39 d after hatching. The characteristics of growth during postembryonic development stages of M. cephalus were investigated,the results showed that the larva and juvenile of M. cephalus belonged to uniform growth type. In addition,the crises period that appeared during postembryonic development stage and the relationship between the development characteristics and life habit were discussed in this paper.