Laboratory of Aquatic Ecology, Evolution and Conservation, University of Leuven, Leuven, Belgium.
Biol Lett. 2013 Jun 12;9(4):20130350. doi: 10.1098/rsbl.2013.0350. Print 2013 Aug 23.
While there is increasing interest in non-consumptive effects of predators on prey, physiological effects are understudied. While physiological stress responses play a crucial role in preparing escape responses, the increased metabolic rates and shunting of energy away from other body functions, including antioxidant defence, may generate costs in terms of increased oxidative stress. Here, we test whether predation risk increases oxidative damage in Enallagma cyathigerum damselfly larvae. Under predation risk, larvae showed higher lipid peroxidation, which was associated with lower levels of superoxide dismutase, a major antioxidant enzyme in insects, and higher superoxide anion concentrations, a potent reactive oxygen species. The mechanisms underlying oxidative damage are likely to be due to the shunting of energy away from antioxidant defence and to an increased metabolic rate, suggesting that the observed increased oxidative damage under predation risk may be widespread. Given the potentially severe fitness consequences of oxidative damage, this largely overlooked non-consumptive effect of predators may be contributing significantly to prey population dynamics.
虽然人们对捕食者对猎物的非消耗性影响越来越感兴趣，但对生理影响的研究却很少。虽然生理应激反应在准备逃避反应方面起着至关重要的作用，但新陈代谢率的增加和能量从其他身体功能（包括抗氧化防御）转移，可能会导致氧化应激增加的成本。在这里，我们测试捕食风险是否会增加 Enallagma cyathigerum 蜻蜓幼虫的氧化损伤。在捕食风险下，幼虫表现出更高的脂质过氧化，这与昆虫中主要的抗氧化酶超氧化物歧化酶水平降低以及活性氧超氧阴离子浓度升高有关。氧化损伤的机制可能是由于能量从抗氧化防御转移，以及代谢率增加，这表明在捕食风险下观察到的氧化损伤增加可能很普遍。鉴于氧化损伤可能对适应性造成严重后果，捕食者的这种被广泛忽视的非消耗性影响可能会对猎物种群动态产生重大影响。
