Marine Biology and Ecology Research Centre, Plymouth University, Plymouth PL4 8AA, UK
Marine Biology and Ecology Research Centre, Plymouth University, Plymouth PL4 8AA, UK.
J Exp Biol. 2018 Apr 20;221(Pt 8):jeb171629. doi: 10.1242/jeb.171629.
With both global surface temperatures and the incidence and intensity of extreme temperature events projected to increase, the assessment of species' sensitivity to chronic and acute changes in temperature has become crucial. Sensitivity predictions are based predominantly on adult responses, despite the fact that early life stages may be more vulnerable to thermal challenge. Here, we compared the sensitivity of different life history stages of the intertidal gastropod using thermal death time curves, which incorporate the intensity and duration of heat stress, and used these to calculate upper critical thermal limits (CT) and sensitivity to temperature change (). Early (larval) life stages had both a lower CT and a lower than adults, suggesting they are less good at withstanding short-term extreme thermal challenges but better able to survive moderate temperatures in the long term. This result supports the predicted trade-off between acute and chronic tolerance to thermal stress, and is consistent with the different thermal challenges that these stages encounter in the intertidal zone. We conclude that different life history stages employ different thermal strategies that may be adaptive. Our findings caution against the use of predictions of the impact of global warming that are based on only adult responses and, hence, which may underestimate vulnerability.
随着全球表面温度以及极端温度事件的发生率和强度预计都将增加，评估物种对温度的慢性和急性变化的敏感性变得至关重要。尽管事实是早期生命阶段可能更容易受到热胁迫的影响，但敏感性预测主要基于成年个体的反应。在这里，我们比较了使用包含热应激强度和持续时间的热死亡时间曲线的方法来评估潮间带腹足纲动物不同生活史阶段的敏感性，并利用这些数据来计算上临界热极限 (CT) 和对温度变化的敏感性 ()。早期（幼虫）生命阶段的 CT 和 均低于成年个体，这表明它们在短期极端热胁迫下的耐受能力较差，但在长期内更能耐受中等温度。这一结果支持了对热应激急性和慢性耐受性之间的预期权衡，并且与这些阶段在潮间带遇到的不同热挑战相一致。我们的结论是，不同的生活史阶段采用不同的热策略，这可能是适应性的。我们的研究结果告诫人们不要仅基于成年个体的反应来预测全球变暖的影响，因为这可能会低估易感性。
