Data from: Additive effects of pCO2 and temperature on respiration rates of the Antarctic pteropod Limacina helicina antarctica

The Antarctic pteropod, Limacina helicina antarctica, is a dominant member of the zooplankton in the Ross Sea and supports the vast diversity of marine megafauna that designates this region as an internationally protected area. Here, we observed the response of respiration rate to abiotic stressors associated with global change – environmentally relevant temperature (-0.8˚C, 4˚C) and pH treatments reflecting current-day and future modeled extremes. Sampling repeatedly over a 14-day period in laboratory experiments and using microplate respirometry techniques, we found that the metabolic rate of juvenile pteropods increased in response to high pCO2 exposure (920 µatm) at -0.8˚C, a near-ambient temperature. Similarly, metabolic rate increased when pteropods were exposed simultaneously to multiple stressors, elevated pCO2 conditions (960 µatm) and a high temperature (+4˚C). Overall, the results showed that pCO2 and temperature interact additively to affect metabolic rates in pteropods. Furthermore, we found that L. h. antarctica can tolerate acute exposure to temperatures far beyond its maximal habitat temperature. Overall, L. h. antarctica appears to be susceptible to pH and temperature stress, two abiotic stressors which are expected to be especially deleterious for ectothermic marine metazoans in polar seas.

南极翼足类（Antarctic pteropod）海若螺南极亚种（Limacina helicina antarctica）是罗斯海浮游动物的优势类群，支撑着该海域丰富的海洋大型动物类群，亦使这片区域被划定为国际保护区。本研究针对与全球变化相关的非生物胁迫，观测了该翼足类的呼吸速率响应：设置贴近野外环境的温度梯度（-0.8℃、4℃），以及反映当前及未来模型预测极端情景的pH处理组。通过为期14天的实验室重复采样实验，并采用微孔板呼吸测定技术（microplate respirometry），我们发现幼体翼足类在接近环境本底温度的-0.8℃条件下暴露于高二氧化碳分压（pCO2，920 µatm）时，代谢速率显著升高。类似地，当翼足类同时暴露于多重胁迫——升高的二氧化碳分压条件（960 µatm）与高温（+4℃）时，其代谢速率同样提升。整体而言，实验结果表明，二氧化碳分压与温度可通过加性互作效应共同调控翼足类的代谢速率。此外，本研究还发现，海若螺南极亚种（L. h. antarctica）能够耐受远超出其栖息地最高温度的急性高温暴露。综上，该亚种对pH与温度胁迫表现出易感性；这两类非生物胁迫预计将对极地海域的外温性海洋后生动物造成尤为严重的危害。