Interpopulational variation in the cold tolerance of a broadly distributed marine copepod.
Interpopulational variation in the cold tolerance of a broadly distributed marine copepod.
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DOI：
10.1093/conphys/cou041
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发表时间：
2014
影响因子：
2.7
通讯作者：
Neufeld CJ
中科院分区：
文献类型：
--
作者：
Wallace GT;Kim TL;Neufeld CJ
采用三个指标研究了潮间带桡足动物加利福尼亚虎爪的耐寒性的种群间差异。所有三个指标都显示出一致的纬度趋势，即来自较冷的北纬地区的人口比来自较温暖的南方地区的人口具有更强的耐寒性。在许多陆生变温动物中已经观察到耐寒性的纬度变化趋势，但很少有研究调查海洋无脊椎动物冷生理的种群间差异。本文以潮间带桡足动物加利福尼亚虎足为模型系统，研究了局部适应如何影响广泛分布的海洋甲壳类动物的耐寒性。在纬度为18°的5个种群中，使用以下三个指标来比较寒性：寒性昏迷发生温度、寒性昏迷恢复时间和冷冻后恢复时间。与来自温暖的南纬地区的桡足类动物相比，北方种群的动物表现出更低的冷昏迷开始温度，更短的冷昏迷恢复时间和更快的冷冻后恢复速度。重要的是，所有三个指标都显示出一致的纬度趋势，这表明任何单一指标都可以等效地用于未来研究耐寒性的纬度变化。我们的结果与先前的研究一致，表明单个物种内的种群可以对空间变化的气候条件表现出强烈的局部适应。因此，在生物气候模型中考虑局部适应将有助于理解加利福尼亚锥虫等广泛分布的物种对人为气候变化的反应。
Three metrics were used to study interpopulational differences in the cold tolerance of the intertidal copepod Tigriopus californicus. All three metrics showed a consistent latitudinal trend in which populations from colder northern latitudes had greater cold tolerance than those from warmer southern locations. Latitudinal trends in cold tolerance have been observed in many terrestrial ectotherms, but few studies have investigated interpopulational variation in the cold physiology of marine invertebrates. Here, the intertidal copepod Tigriopus californicus was used as a model system to study how local adaptation influences the cold tolerance of a broadly distributed marine crustacean. Among five populations spanning 18° in latitude, the following three metrics were used to compare cold tolerance: the temperature of chill-coma onset, the chill-coma recovery time and post-freezing recovery. In comparison to copepods from warmer southern latitudes, animals from northern populations exhibited lower chill-coma onset temperatures, shorter chill-coma recovery times and faster post-freezing recovery rates. Importantly, all three metrics showed a consistent latitudinal trend, suggesting that any single metric could be used equivalently in future studies investigating latitudinal variation in cold tolerance. Our results agree with previous studies showing that populations within a single species can display strong local adaptation to spatially varying climatic conditions. Thus, accounting for local adaptation in bioclimate models will be useful for understanding how broadly distributed species like T. californicus will respond to anthropogenic climate change.