Global warming is a worldwide phenomenon affecting the functioning of diverse ecosystems, including fresh waters. Temperature increase affects physiology and behaviour of ectotherms due to growing energetic demands necessary to sustain increased metabolic rate. Anti-predator responses may resemble temperature-induced changes in organisms, suggesting synergism between these factors. To check how temperature shapes physiological and behavioural responses of ectotherms to predation risk, we exposed amphipods: Dikerogammarus villosus and Gammarus jazdzewskii to fish kairomones at 10, 17 or 24 °C. Animals were placed in tanks where temperature was gradually adjusted to the desired test temperature and acclimated under such conditions for 3 subsequent days. Then they were exposed to the predator cue (the Eurasian perch kairomone) for 35 min to test their acute responses. We measured metabolic rate (as respiration), antioxidant defence (CAT: catalase activity, TAS: total antioxidant status), oxidative molecules (TOS: total oxidative status), oxidative damage (TBARS: thiobarbituric acid reactive substances) and behaviour (locomotor activity). Amphipods increased respiration with raising temperature and when exposed to predation risk (all temperatures). Only G. jazdzewskii exhibited increased TOS when exposed to 24 °C or to predation risk at all temperatures. Antioxidant defence increased with raising temperature (CAT, TAS) and decreased under predation risk (CAT). Cellular damage increased in G. jazdzewskii under predation risk at 10 and 24 °C, but raised temperature itself did not generate any damage. Amphipods reduced locomotor activity at 24 °C. Thus, at elevated temperatures, amphipods minimized their cellular damage at the cost of increased antioxidant defence and lower locomotor activity (potentially disadvantageous under higher energetic demands). Under predation risk, the performance of antioxidant systems was reduced, probably due to energy allocation into anti-predatory mechanisms, leading to increased cellular damage at suboptimum temperatures. Thus, negative consequences of elevated temperature for organisms may be amplified by changes in behaviour (compromising food acquisition) and non-consumptive predator effects.

全球变暖是一种全球性现象，影响着包括淡水在内的多种生态系统的功能。由于维持新陈代谢速率所必需的不断增长的能量需求，温度升高会影响等温线的生理和行为。抗捕食者的反应可能类似于温度引起的生物体变化，表明这些因素之间存在协同作用。为了检查温度如何影响外温对捕食风险的生理和行为反应，我们暴露了两栖类：两足类动物Dikerogammarus villosus和Gammarus jazdzewskii在10、17或24°C下捕捞海洛酮。将动物放在槽中，在槽中将温度逐渐调节至所需的测试温度，并在此条件下适应3天。然后，将它们暴露于捕食者线索（欧亚鲈鱼海洛酮）中35分钟，以测试其急性反应。我们测量了代谢率（作为呼吸），抗氧化剂防御（CAT：过氧化氢酶活性，TAS：总抗氧化剂状态），氧化分子（TOS：总氧化状态），氧化损伤（TBARS：硫代巴比妥酸反应性物质）和行为（运动能力） 。两栖类动物随着温度升高以及暴露于被捕食的风险（所有温度）时，呼吸都会增强。只有G. jazdzewskii暴露于24°C或在所有温度下都有捕食风险时，TOS升高。抗氧化剂的防御作用随着温度的升高而增加（CAT，TAS），而在掠食风险下（CAT）则降低。G. jazdzewskii中的细胞损伤增加在10和24°C下有被捕食的危险，但温度升高本身并未产生任何损害。两栖动物降低了24°C的运动能力。因此，在升高的温度下，两栖类动物以增加的抗氧化剂防御能力和较低的运动活性为代价（在较高的能量需求下可能不利）而将其对细胞的损害最小化。在具有捕食风险的情况下，抗氧化剂系统的性能会降低，这可能是由于能量分配到了反捕食机制中，导致在次适温下细胞损伤增加了。因此，行为改变（危害食物获取）和非消耗性捕食者效应可能会加剧高温对生物体的负面影响。