High Heat Tolerance Is Negatively Correlated with Heat Tolerance Plasticity in Nudibranch Mollusks
High Heat Tolerance Is Negatively Correlated with Heat Tolerance Plasticity in Nudibranch Mollusks
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DOI：
10.1086/704519
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发表时间：
2019-07-01
影响因子：
1.6
通讯作者：
Stillman, Jonathon H.
中科院分区：
文献类型：
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作者：
Armstrong, Eric J.;Tanner, Richelle L.;Stillman, Jonathon H.
快速的海洋变暖可能会改变海洋外温动物的栖息地适宜性和种群适应性。对热扰动的敏感性将部分取决于物种的性能上限（CTmax）的可塑性。然而，我们目前缺乏数据CTmax可塑性的几个主要的海洋类群，包括裸鳃类软体动物，从而限制了这些物种的栖息地变暖的预测反应。为了确定未来变暖的相对敏感性，我们调查了耐热极限（CTmax），耐热可塑性（适应反应比），热安全系数，代谢的温度敏感性，和代谢成本的热休克9种裸鳃类收集在整个热梯度沿着东北太平洋沿岸的加州，并在环境温度和高温下进行热驯化。种间耐热性差异显著，范围为25.4 ± 0.5 ℃至32.2 ± 1.8 ℃（xoer bar ± SD），但种内不随采集地点而变化。热可塑性一般较高（0.52 +/- 0.06，x oer bar +/- SE），与CTmax呈强负相关，符合热适应的权衡假设。热挑战的代谢成本很低，任何物种暴露于急性热休克后1小时的呼吸速率没有显着变化。根据最高栖息地温度计算的热安全裕度，几乎所有被检查的物种都是负数（-8.5摄氏度+/- 5.3摄氏度，x棒+/- CI [置信区间]）。从这些数据中，我们得出结论，温暖的适应潮间裸鳃类限制塑料反应急性热挑战，南部温暖适应的物种可能是最ulnerable未来变暖。
Rapid ocean warming may alter habitat suitability and population fitness for marine ectotherms. Susceptibility to thermal perturbations will depend in part on plasticity of a species' upper thermal limits of performance (CTmax). However, we currently lack data regarding CTmax plasticity for several major marine taxa, including nudibranch mollusks, thus limiting predictive responses to habitat warming for these species. In order to determine relative sensitivity to future warming, we investigated heat tolerance limits (CTmax), heat tolerance plasticity (acclimation response ratio), thermal safety margins, temperature sensitivity of metabolism, and metabolic cost of heat shock in nine species of nudibranchs collected across a thermal gradient along the northeastern Pacific coast of California and held at ambient and elevated temperature for thermal acclimation. Heat tolerance differed significantly among species, ranging from 25.4 degrees +/- 0.5 degrees Cto 32.2 degrees +/- 1.8 degrees C(xoer bar +/- SD ), but did not ary with collection site within species. Thermal plasticity was generally high (0.52 +/- 0.06 , x oer bar +/- SE ) and was strongly negatiely correlated with CTmax in accordance with the trade-off hypothesis of thermal adaptation. Metabolic costs of thermal challenge were low, with no significant alteration in respiration rate of any species 1 h after exposure to acute heat shock. Thermal safety margins, calculated against maximum habitat temperatures, were negatie for nearly all species examined (-8.5 degrees +/- 5.3 degrees C , x oer bar +/- CI [confidence interal]). From these data, we conclude that warm adaptation in intertidal nudibranchs constrains plastic responses to acute thermal challenge and that southern warm-adapted species are likely most ulnerable to future warming.