Tempereature tolerance and developmental phenotypic plasticity in early life stage fish

全球气候变化正在推动世界范围内河流系统温度上升的总趋势。因此，人为因素导致的当地水环境温度升高可能会对这些生态系统中的鱼类造成巨大的选择压力。动物如何应对环境的变化将预测种群对这些未来条件的反应。虽然我们对鱼类对变暖和降温的急性反应了解很多，但我们对热史如何促进生理调节，从而保护鱼类免受慢性变暖或间歇性加热事件的影响知之甚少。我的研究项目集中在早期生命阶段鱼类的表型反应，以及暴露在高温下如何增强对未来热挑战的保护。为了解决这个问题，我打算描述在仔鱼和幼鱼发育期间以及由于预先暴露在温度升高的结果而获得的热保护的大小和时间。我还将描述在不同的温度制度下饲养卵或仔鱼时，永久性的热保护比例(即，发育可塑性的结果，而不是通过驯化的结果)。然后，在更广泛的生活史特征的背景下，研究这种对温度升高的表型可塑性，我将检验这样的假设，即鱼类较长的世代时间将与可逆表型的倾向相关，因为永久适应当前条件的选择性压力可能较小。

Global climate change is contributing to a general trend of increased temperatures in river systems worldwide. Consequently, temperature increases in local aquatic environments driven by human sources may be inducing intense selection pressures on fish in these ecosystems. How animals cope with changes in their environment will predict how populations respond to these future conditions. While we understand a great deal about acute responses to warming and cooling in fish, we know much less about how thermal history might promote physiological adjustments that result in protection from chronic warming or episodic heating events. My research program focuses on the phenotypic responses of early life stage fish, and how exposure to elevated temperature may enhance protection from future thermal challenge. To address this, I intend to characterize the magnitude and timing of thermal protection acquired during development of larvae and juvenile fish, and as a result of pre-exposure to increased temperatures. I will also describe the proportion of thermal protection that is permanent (i.e., a result of developmental plasticity, as opposed to through acclimation) when eggs or larval fish are reared under different thermal regimes. Examining, then, this phenotypic plasticity to elevated temperatures over the broader context of life history characteristics, I will test the hypothesis that longer generational times in fish will be associated with a propensity for reversible phenotypes, as there may be less selective pressure to permanently adjust to current conditions.