不同海水酸化模式对马粪海胆胚胎和浮游幼体骨针发育的影响

摘要

为了比较CO2引起的海水酸化和HCI引起的海水酸化对棘皮动物的影响,本研究以中国北方海岸带土著种-马粪海胆(Hemicentrotus pulcherrimus)为对象,分析比较了两种海水酸化模式对马粪海胆胚胎和骨针发育的影响.根据IPCC对2100年海水酸化程度的预测,在实验室条件下,建立了自然海水组(pH=8.06± 0.01)和六个海水酸化处理组(三个CO2处理组和三个HCI处理组).结果表明:(1)与自然海水组相比,酸化处理组马粪海胆胚胎的卵裂率呈现随海水pH下降而延长的趋势,与HCI酸化处理相比,CO2处理对马粪海胆胚胎卵裂率的影响更为严重;(2)两种海水酸化模式下,马粪海胆浮游幼体四腕浮游幼体均出现对称性缺失和骨针外露现象;(3)与自然海水组相比,两种海水酸化模式对马粪海胆四腕浮游幼体骨针发育具有不同影响,HCI酸化处理组浮游幼体呈现骨针变短现象,而CO2处理组四腕幼体的骨针则出现变长现象;(4)扫描电镜结果显示,海水酸化可影响马粪海胆浮游幼体骨针的钙化结构,当海水△pH=-0.5时,CO2处理组马粪海胆浮游幼体骨针的腐蚀程度要比HCI处理组更为严重.本研究结果提示,不同的海水酸化模式对马粪海胆胚胎和骨针发育有不同程度的影响,相比强酸(HCl)引起的海水酸化而言,CO2引起的海水酸化对马粪海胆的影响更为严重.%To compare the effects of CO2-induced seawater acidification and HCI-induced seawater acidification on benthic echinoderms,Hemicentrotus pulcherrimus inhibiting intertidal coastal zone in northern China was utilized in the current study.Under two seawater acidification scenario conditions,embryogenesis and larval spicule development were investigated and compared,respectively.Based on the projection of IPCC,present natural seawater condition (pH=8.06 ± 0.01) and six laboratory-controlled acidified conditions (three CO2-treated groups and three HCI-treated groups,respectively) were set up.Results showed that:(a) early embryonic cleavage tended to be delayed as pH declined in all acidified seawater groups,embryonic cleavage delay of CO2-treated groups tended to be more severe as compared to that of HCI-treated groups;(b) impaired larval symmetry were observed both in CO2-treated groups and HCI-treated groups,there was no significant difference between the two;(c) alteration in skeletal elements was observed in all acidified groups as compared to control,and elongated spicules were observed in CO2-treated groups and shorten spicules were found in HCI-treated groups.Also,when A pH=-0.5,spicule corrosion in CO2-treated group was worse than that in HCI-treated group.All data observed in this study suggest that different seawater acidification scenarios had different effects on sea urchins.Compared to HCI-induced seawater acidification,the effects of CO2-induced seawater acidification on sea urchins were more profound.