Data from: Developmental plasticity of the stress response in female but not male guppies

To survive, animals must respond appropriately to stress. Stress responses are costly, so early-life experiences with potential stressors could adaptively tailor adult stress responses to local conditions. However, how multiple stressors influence the development of the stress response remains unclear, as is the role of sex. Trinidadian guppies (Poecilia reticulata) are small fish with extensive life history differences between the sexes and population variation in predation pressure and social density. We investigated how sex and early-life experience influence hormonal stress responses by manipulating conspecific density and perceived predation risk during development. In adults, we sampled cortisol twice to measure initial release and change over time in response to a recurring stressor. The sexes differed considerably in their physiological stress response. Males released more cortisol for their body mass than females and did not reduce cortisol release over time. By contrast, all females, except those reared at high density with predation cues, reduced cortisol release over time. Cortisol responses of males were less dynamic in response to current circumstances and early-life experiences than females, consistent with life history differences between the sexes. Our study underscores the importance of early-life experiences, interacting ecological factors, and sex differences in the organization of the stress response.为生存所需，动物必须对压力作出恰当应对。压力应对存在显著能量代价，因此早期接触潜在压力源的经历，可使成年个体的压力应对策略适应性地匹配当地环境条件。然而，多种压力源如何影响压力应对系统的发育，以及性别在其中的作用，目前仍不明确。特立尼达孔雀鱼（Trinidadian guppies，学名Poecilia reticulata）是一种小型鱼类，其两性间存在广泛的生活史差异，且不同种群在捕食压力与社会密度上存在变异。本研究通过操控发育阶段的同种个体密度与感知到的捕食风险，探究了性别与早期生活经历如何影响激素介导的压力应对反应。针对成年个体，我们两次采集样本以测量初始皮质醇释放量，以及其对重复压力刺激的响应随时间的变化情况。研究发现，两性的生理压力应对反应存在显著差异：相较于雌性，雄性的单位体重皮质醇释放量更高，且未随时间推移降低皮质醇释放量。与之相反，除了在高种群密度且伴随捕食线索的环境中发育的雌性个体外，其余雌性的皮质醇释放量均随时间推移而降低。雄性的皮质醇应对反应在响应当前环境与早期生活经历时，其动态性弱于雌性，这与两性间的生活史差异相符。本研究强调了早期生活经历、相互作用的生态因子，以及性别差异在压力应对系统调控中的重要性。