Abstract: In order to study the impact of seawater acidification on early development of sea urchin Hemicentrotus pulcherrimus, this paper took 2 methods of CO2-induced and HCl-induced to simulate seawater acidification. According to IPCC prediction, the experiment designed one nature seawater group (Control, nature seawater pH), 3 CO2 treatment groups (OA1-CO2, OA2-CO2 and OA3-CO2, ΔpH=-0.3, -0.4, -0.5 units, respectively), and 3 HCl treatment groups (OA1-HCl,OA2-HCl and OA3-HCl, ΔpH=-0.3,-0.4,-0.5 units, respectively). Results showed that: ① these 2 methods had no significant effect on fertilization rate (P>0.05). ② Compared with nature seawater group, the embryo swimming percentage of H. pulcherrimus in all groups were decreased, but that in OA1-CO2 and OA1-HCl treatment groups were decreased remarkably (P<0.05), while that in other treatment groups (OA2-CO2, OA3-CO2, OA2-HCl and OA3-HCl treatment groups) were decreased (P<0.01). ③ Meanwhile, CO2-induced and HCl- induced seawater acidification also affected four-arm pluteus survival rate of H. pulcherrimus. The larval survival rate in majority of treatment groups (except the OA1-HCl treatment group) was remarkably decreased (P<0.01). Compared to that of nature seawater group, the larval survival rate of OA1-HCl treatment group was decreased significantly (P<0.05). The survival rates of other groups were also remarkably reduced (P<0.01). ④ Under CO2-induced seawater acidification conditions, we found that symmetry structure of four-arm pluteus was lost with the increasing of seawater pH, while there was no significant structure change of four-arm pluteus reared in HCl treatment groups. All results demonstrated that in the near future seawater acidification has an important effect on early development of sea urchin H. pulcherrimus, especially the seawater acidification induced by CO2.

Key words: Hemicentrotus pulcherrimus, seawater acidification, embryo, early development

摘要： 采用二氧化碳（CO2）和强酸（HCl）模拟海水酸化，研究未来海水酸化对马粪海胆（Hemicentrotus pulcherrimus）胚胎早期 发育的影响。根据IPCC预测，实验设置了1 个自然海水组、3 个CO2酸化胁迫组:OA1-CO2（自然海水pH降0.3）、OA2-CO2（自 然海水pH降0.4）和OA3-CO2（自然海水pH降0.5））；3个HCl酸化胁迫组：OA1-HCl（自然海水pH降0.3）、OA2-HCl（自然海水 pH降0.4）和OA3-HCl（自然海水pH降0.5）。结果显示：①两种海水酸化模式对马粪海胆受精率并无显著影响（P>0.05）；② 与自然海水组相比，两种酸化模式下马粪海胆胚胎上浮率均呈下降趋势，其中OA1-CO2组和OA1-HCl组胚胎上浮率显著降低且差 异显著（P<0.05），其余各酸化胁迫组胚胎上浮率则呈极显著降低趋势（P<0.01）；③随着酸化程度的加深，两种酸化模式下 马粪海胆四腕浮游幼体存活率较自然海水组均呈下降趋势，与自然海水组相比，OA1-HCl组存活率显著降低（P<0.05），其余 各酸化胁迫组存活率降低程度极为显著（P<0.01）；④与自然海水组相比，CO2酸化胁迫组马粪海胆四腕浮游幼体的对称性缺 失现象随酸化程度的加深而加剧，而HCl酸化胁迫对马粪海胆四腕浮游幼体对称性并无明显影响。结果提示，未来海水酸化对 马粪海胆早期发育具有重要影响，与HCl酸化模式相比，由CO2导致的海水酸化对马粪海胆胚胎早期发育的影响更为复杂。

关键词: 马粪海胆, 海水酸化, 胚胎, 早期发育