Seawater carbonate chemistry and total wet weight, metabolically active tissue, ingestion rate and oocyte diameter of Adult Mussels Mytilus chilensis

The effect of CO2-driven ocean acidification (OA) on marine biota has been extensively studied mostly on a single stage of the life cycle. However, the cumulative and population-level response to this global stressor may be biased due to transgenerational effects and their impacts on physiological plasticity. In this study, we exposed adult mussels Mytilus chilensis undergoing gametogenesis to two pCO2 levels (550 and 1200 μatm) for 16 weeks, aiming to understand if prolonged exposure of reproductive individuals to OA can affect the performance of their offspring, which, in turn, were reared under multiple stressors (pCO2, temperature, and dissolved cadmium). Our results indicate dependence between the level of pCO2 of the broodstock (i.e., parental effect) and the performance of larval stages in terms of growth and physiological rates, as a single effect of temperature. While main effects of pCO2 and cadmium were observed for larval growth and ingestion rates, respectively, the combined exposure to stressors had antagonistic effects. Moreover, we found a suppression of feeding activity in post-spawning broodstock upon high pCO2 conditions. Nevertheless, this observation was not reflected in the final weight of the broodstock and oocyte diameter. Due to the ecological and socioeconomic importance of mussels' species around the globe, the potential implications of maternal effects for the physiology, survival, and recruitment of larvae under combined global-change stressors warrant further investigation.

由二氧化碳驱动的海洋酸化（Ocean Acidification, OA）对海洋生物群落的影响已被广泛研究，但绝大多数研究仅聚焦于生物生命周期的单个阶段。然而，由于跨代效应及其对生理可塑性的影响，针对这一全球胁迫因子的累积效应与种群水平响应可能存在偏差。本研究将处于配子发生阶段的成年智利贻贝（Mytilus chilensis）暴露于两种二氧化碳分压（pCO2）水平（550与1200 μatm）的环境中16周，旨在探究繁殖个体长期暴露于海洋酸化环境是否会影响其子代的表现，而子代将进一步被置于多重胁迫（pCO2、温度与溶解态镉）环境下培育。研究结果显示，亲贝的二氧化碳分压暴露水平（即亲本效应）与幼虫阶段在生长及生理速率层面的表现存在相关性，且该相关性同样受温度单一效应的影响。尽管pCO2与镉的主效应分别体现在幼虫生长与摄食速率上，但多重胁迫的联合暴露却表现出拮抗效应。此外，我们还发现，在高pCO2环境下，产卵后的亲贝摄食活动受到抑制。尽管如此，该现象并未体现在亲贝的最终体重与卵母细胞直径上。鉴于全球范围内贻贝物种所具备的生态与社会经济重要性，亲本效应在多重全球变化胁迫下对幼虫生理、存活及种群补充的潜在影响值得进一步研究。