Data from: Plastic responses of bryozoans to ocean acidification

Phenotypic plasticity has the potential to allow organisms to respond rapidly to global environmental change, but the range and effectiveness of these responses are poorly understood across taxa and growth strategies. Colonial organisms might be particularly resilient to environmental stressors, as organizational modularity and successive asexual generations can allow for distinctively flexible responses in the aggregate form. We performed laboratory experiments to examine the effects of increasing dissolved carbon dioxide (i.e. ocean acidification) on the colonial bryozoan Celleporella cornuta sampled from two source populations within a coastal upwelling region of the northern California coast. Bryozoan colonies were remarkably plastic under these carbon dioxide (CO2) treatments. Colonies raised under high CO2 grew more quickly, investing less in reproduction and producing lighter skeletons when compared to genetically identical clones raised under current atmospheric values. Bryozoans held in high CO2 conditions also changed the Mg/Ca ratio of skeletal walls and increased the expression of organic coverings in new growth, which may serve as protection against acidified water. We also observed strong differences between populations in reproductive investment and organic covering reaction norms, consistent with adaptive responses to persistent spatial variation in local oceanographic conditions. Our results demonstrate that phenotypic plasticity and energetic trade-offs can mediate ecological responses to global environmental change, and highlight the broad range of strategies available to colonial organisms.

表型可塑性（phenotypic plasticity）赋予生物快速响应全球环境变化的潜力，但目前学界对不同类群与生长策略下这类响应的范围与有效性仍知之甚少。群体生物或许对环境胁迫具备更强的耐受能力，因其组织模块化与连续无性世代可使其整体形态呈现出显著灵活的响应模式。
本研究开展室内实验，探究溶解二氧化碳浓度升高（即海洋酸化）对采自加利福尼亚北部海岸沿岸上升流区域两个源种群的群体苔藓虫Celleporella cornuta的影响。
在该二氧化碳（CO₂）处理条件下，苔藓虫群体展现出极强的表型可塑性。与当前大气二氧化碳浓度条件下培养的遗传同源克隆相比，高二氧化碳浓度环境中培育的群体生长速度更快，但其对繁殖的资源投入更少，且骨骼结构更轻薄。处于高二氧化碳环境的苔藓虫，其骨骼细胞壁的镁钙比（Mg/Ca ratio）发生改变，且新生组织中有机覆盖物的表达量上升，这或许可作为抵御酸化水体的保护机制。
本研究还发现，不同种群在繁殖资源投入与有机覆盖物反应规范上存在显著差异，这与当地海洋环境条件持续空间变异下的适应性响应相符。
本研究结果表明，表型可塑性与能量权衡可介导生物对全球环境变化的生态响应，并凸显了群体生物所具备的多样适应策略。