Supplementary material to: 'Changing feeding levels reveal plasticity in elasmobranch life history strategies'

Lucas S, Berggren P, Barrowclift E, Smallegange IM. 2024. Changing feeding levels reveal plasticity in elasmobranch life history strategies. <i>Preprint</i>. Life history strategies are shaped by phylogeny, environmental conditions and individual energy budgets, and have implications for population performance. Here, we used an approach that merges demography with energy budget theory to structure life history traits of 151 elasmobranch species into life history strategies for two contrasting feeding levels. We assessed how phylogeny and habitat impacted life history strategies, and tested if these strategies predict population performance and conservation status. Elasmobranch life history strategies are structured along the fast-slow continuum and reproductive strategy axes. However, species’ positions in this life history space were not fixed, but instead moved in an anticlockwise ‘whirlpool’ manner along the two axes in response to an increase in feeding level. We also found that population growth rate does not necessarily inform on a species demographic resilience. Finally, only at the higher feeding level does the fast-slow continuum predict IUCN conservation status, with the slowest species at the highest risk of extinction. Our analyses reveal plasticity in species life history strategies, and warn against extrapolating the fast-slow continuum and reproductive strategy framework from one environment to another when predicting a species’ response to (climate) change, perturbations, and, particularly in case of elasmobranchs, (over)exploitation.

Lucas S、Berggren P、Barrowclift E、Smallegange IM. 2024年。《改变摄食水平揭示板鳃类（elasmobranch）生活史策略的可塑性》。预印本。生活史策略由系统发育、环境条件与个体能量收支共同塑造，并对种群表现具有重要影响。本研究采用将种群统计学与能量收支理论相结合的方法，将151种板鳃类的生活史特征按照两种截然不同的摄食水平归类为不同的生活史策略。研究评估了系统发育与栖息地对生活史策略的影响，并检验了这些策略能否预测种群表现与保护等级。板鳃类的生活史策略沿快慢连续谱（fast-slow continuum）与繁殖策略轴构建分布，但物种在该生活史空间中的位置并非固定不变，而是随着摄食水平提升，沿双轴以逆时针“涡旋”的方式移动。本研究同时发现，种群增长率未必能反映物种的种群恢复力。最后，仅在较高摄食水平下，快慢连续谱才能预测国际自然保护联盟（IUCN）的保护等级，且生活史最慢的物种面临最高的灭绝风险。本研究的分析结果揭示了物种生活史策略的可塑性，并警示在预测物种对（气候）变化、扰动以及尤其是板鳃类所面临的（过度）开发的响应时，不应将快慢连续谱与繁殖策略框架从某一环境外推至其他环境。