不同pH对海湾扇贝胚胎发育及幼虫生长发育的影响

Effects of Different pH on Embryo Development and Larval Growth of Bay Scallop(Argopecten irradia)

为探究pH对海湾扇贝(Argopecten irradia)胚胎发育及幼虫生长发育的影响,本研究以pH8.0~8.2为对照组,分析不同pH(分别为7.6~7.7、7.3~7.4、7.0~7.1和6.7~6.8)对海湾扇贝胚胎及幼虫的影响。结果显示,随着pH的降低,各实验组孵化率降低,畸形率增高,孵化时间延长,且幼虫个体明显小于对照组(P<0.05)。D形幼虫期与壳顶幼虫期幼虫存活率与生长速率均显著低于对照组(P<0.05)。幼虫发育至第8天时,pH 7.0~7.1与pH 6.7~6.8实验组的存活率分别为6.1%和5.6%,而对照组为75.2%,除pH 7.6~7.7组外,各实验组生长速率均在3.4μm/d及以下,基本呈现生长停滞状态。眼点幼虫附着率与对照组差异显著(P<0.05),第7天时,pH6.7~6.8实验组附着率仅为31.7%。研究表明,海水pH变化对海湾扇贝早期胚胎及幼虫生长发育具有显著影响,该研究为评估pH变化对海湾扇贝等经济贝类资源和养殖产业的影响提供了参考资料。

To explore the influence of pH on embryo development and larval growth of bay scallop(Argopecten irradia),pH 8.0~8.2 was set as the control group to analyze the influence of different pH(7.6~7.7,7.3~7.4,7.0~7.1,and 6.7~6.8)on the development of embryos and larva of bay scallop.The results showed that with decrease in pH,the hatching rate of embryos in each experimental group decreased,the deformity rate increased,hatching time was prolonged,and the larva were significantly smaller than those in the control group(P<0.05).The survival rate and growth rate of D-larvae and top umbo larvae were significantly lower than those of the control group(P<0.05).The survival rates of the pH 7.0~7.1 and pH 6.7~6.8 experimental groups were 6.1%and 5.6%,respectively,and 75.2%in the control group on the 8 th day of larva development.The growth rates of each experimental group were 3.4μm/d and below,except for the pH 7.6~7.7 group,which basically showed a state of growth stagnation.There was a significant difference in the adhesive rate between the experimental group and the control group(P<0.05).On the 7 th day,the adhesive rate of the pH 6.7~6.8 experimental group was only 31.7%.The results showed that the change in seawater pH had a significant effect on early embryo and larva development in bay scallop,which provides a reference for the evaluation of the effects of pH change on economic shellfish resources,such as bay scallop and others in the aquaculture industry.