金乌贼和曼氏无针乌贼胚胎发育及其盐度耐受能力的比较研究

采集金乌贼(Sepia esculenta)及曼氏无针乌贼(Sepiella maindroni)受精卵,观察了金乌贼胚胎发育过程,比较分析了2种乌贼受精卵和仔乌的形态特征;分别研究了金乌贼受精卵在盐度20,25,30(对照)、33,36及曼氏无针乌贼受精卵在盐度15,20,25,30(对照)、36条件下的孵化率,分析了2种乌贼受精卵在192 h盐度突变过程中卵液渗透压和受精卵Na~+/K~+-ATPase活力的变化,比较了其在相同盐度20,25,30,36条件下的孵化率及耐受盐度突变的生理适应过程.结果表明,金乌贼胚胎发育第7天器官开始分化,第14天器官开始形成,盐度30、水温22～24℃时,其孵化时间为20～21 d;盐度30处理组,2种乌贼受精卵的孵化率均显著高于其他盐度处理组(P<0.01);在192 h盐度突变过程中,2种乌贼受精卵卵液渗透压随环境盐度的变化而变化,金乌贼受精卵卵液渗透压与环境渗透压相等,而曼氏无针乌贼受精卵卵液渗透压比环境渗透压平均高出60 mOsm/kg,2种乌贼受精卵均未检测到Na~+/K~+-ATPase活性.比较发现,虽然2种乌贼受精卵调节渗透压能力均较弱,但曼氏无针乌贼受精卵比金乌贼能更好地适应盐度变化.本研究旨在探明两种乌贼受精卵对盐度的适应性,为开展规模化人工繁育与资源增殖提供基础依据.

A comparative study of Sepia esculenta and Sepiella maindroni on embryonic development and ability of salinity tolerance

Fertilized eggs of Sepia esculenta and Sepiella maindroni were collected from the wild and the embryonic development of S.esculenta was observed in laboratory.The morphological characters of fertilized eggs and newly hatched larvae between the two species were also compared.The effects of different seawater salinities of 20,25,30 (control),33,36 for S.esculenta and 15,20,25,30 (control),36 for S.maindroni on hatching rate were studied,respectively.Changes in egg fluid osmolality and egg Na+/K+-ATPase activi...