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），即南极海若螺（Limacina helicina antarctica），是罗斯海（Ross Sea）浮游动物（zooplankton）的优势类群，支撑了该区域丰富的海洋巨型动物（marine megafauna）多样性，也使得这片海域成为国际保护区。本研究针对全球变化相关的非生物胁迫因子——与环境实际情况匹配的温度梯度（-0.8℃、4℃）以及反映当前与未来模拟极端状况的pH处理组，观测了其呼吸速率的响应。实验于实验室环境下开展，在14天周期内进行重复采样，并采用微孔板呼吸测定技术（microplate respirometry），研究发现幼体翼足类在接近原生环境温度的-0.8℃条件下，暴露于高二氧化碳分压（pCO2，920微大气压（µatm））时代谢速率显著上升。类似地，当翼足类同时暴露于多重胁迫因子——升高的二氧化碳分压（pCO2，960微大气压（µatm））与高温（+4℃）时，其代谢速率同样升高。整体而言，研究结果表明二氧化碳分压（pCO2）与温度以加性效应共同调控翼足类的代谢速率。此外，本研究发现南极海若螺（Limacina helicina antarctica）能够耐受远超其栖息地最高温度的急性高温暴露。综上，南极海若螺似乎对pH与温度胁迫较为敏感，这两类非生物胁迫因子预计会对极地海域的变温海洋后生动物（ectothermic marine metazoans）造成尤为严重的危害。