Characterizing the potential for, and mechanisms of, organismal response to environmental stress, particularly in the context of temperature, remains important for predicting effects of global change on natural populations. A number of studies have looked at changes in behavioral variation, focusing primarily on activity, boldness and aggression, while many behavioral traits have gone unexplored. In this study, I examine responses of a widespread neotropical livebearer, the barred killifish, to variation in water temperature. In addition to activity and boldness, I assayed variation in anxiety (measured as thigmotaxis – preference for edges) following a short-term exposure to thermal stress. Similar to other studies, elevated temperatures were associated with significant increases in activity and propensity for risk-taking behavior. There was no effect of thermal stress on anxiety, but males did have overall lower anxiety than females. An increase in activity and boldness may be a general response to thermal stress, even if competing hypotheses of the adaptive benefit remain unresolved. The insensitivity of thigmotaxis to thermal stress suggests that this measure of anxiety may be independent of variation along the shy-bold axis and therefore represent a useful measure for future studies of behavioral variation.

中文翻译：

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热应激会增加活鱼的活动和冒险行为，但不会增加焦虑

表征生物体对环境压力的反应的潜力和机制，特别是在温度的背景下，对于预测全球变化对自然种群的影响仍然很重要。许多研究着眼于行为变异的变化，主要关注活动、大胆和攻击性，而许多行为特征尚未得到探索。在这项研究中，我研究了一种广泛分布的新热带活体鱼类，即被禁止的鳉鱼，对水温变化的反应。除了活跃度和胆量之外，我还分析了短期暴露于热应激后焦虑的变化（以触感——对边缘的偏好来衡量）。与其他研究类似，温度升高与活动和冒险行为倾向的显着增加有关。热应激对焦虑没有影响，但男性的焦虑总体上确实低于女性。活动和胆量的增加可能是对热应激的普遍反应，即使适应性益处的竞争假设仍未得到解决。触感对热应激的不敏感性表明，这种焦虑的衡量标准可能与沿害羞轴的变化无关，因此代表了未来行为变化研究的有用衡量标准。