Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.
Reintroduction is an increasingly common conservation tool used to recover populations of imperilled species, but its success depends on the suitability of the introduced animals’ phenotype for their new habitat. For fishes, thermal tolerance may be a key trait in urbanized habitats. We compared thermal tolerance (CTmax) among three lineages (western, central, eastern) of imperilled redside dace (Clinostomus elongatus). CTmax of eastern adults was 3–4 °C lower than that of the other lineages, but adults of each lineage had similar thermal acclimation responses. In contrast, the acclimation response of juveniles differed by ∼80% between the central and western lineages. Using these data, we predicted how each lineage would fare in a hypothetical reintroduction to relatively warm urbanized habitats. Owing to the differences in juvenile acclimation responses, predicted thermal safety margins for the central lineage were double those predicted for the western lineage. Overall, we suggest that CTmax is a useful trait to incorporate into the source population selection process; however, there is an urgent need for the establishment of captive experimental research populations of imperilled species to address remaining uncertainties.

中文翻译：

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为保护性重新引入选择源种群：从濒危红斑鱼种群间热耐受性变化的经验教训

加拿大渔业和水产科学杂志，提前印刷。
重新引入是一种越来越常见的保护工具，用于恢复濒危物种的种群，但其成功取决于引入动物的表型对其新栖息地的适用性。对于鱼类来说，耐热性可能是城市化栖息地的一个关键特征。我们比较了濒危红斑鱼（Clinostomus elongatus）的三个谱系（西部、中部、东部）的耐热性（CTmax）。东部成虫的 CTmax 比其他谱系低 3-4 °C，但每个谱系的成虫具有相似的热适应反应。相比之下，中西部谱系之间幼鱼的适应反应相差约 80%。使用这些数据，我们预测了每个谱系在假设重新引入相对温暖的城市化栖息地时的表现。由于幼年适应反应的差异，中央谱系的预测热安全裕度是西部谱系预测的两倍。总的来说，我们建议 CTmax 是一个有用的特征，可以纳入源种群选择过程；然而，迫切需要建立濒危物种的圈养实验研究种群，以解决剩余的不确定性。