As acute stress induced by predation risk can generate significant oxidative damage, prey organisms are forced to balance their defence reaction and the cost of activating the cellular defence system. Stress tolerance differs significantly among species; therefore predator pressure indirectly shapes the community structure. To test adaptation abilities of amphipod crustaceans (Dikerogammarus villosus and Gammarus jazdzewskii) we exposed them to acute (35 min.) and chronic (1 or 7 days) predation risk (the Eurasian perch). We measured respiration (related to metabolic rate), cellular defence systems (antioxidant enzyme (catalase) activity and heat shock protein (Hsp70) concentration), and the level of oxidative damage (thiobarbituric acid reactive substances (TBARS) concentration). Both amphipods increased their respiration rate in the presence of predation cues, irrespective of the duration of their pre-exposure to danger. This increase in D. villosus was initiated more quickly (immediately vs. after 10 min. of the test) and lasted for a longer time (20 vs. 10 min.) than in G. jazdzewskii. However, only G. jazdzewskii after a short exposure to predation risk exhibited an increase in its catalase activity, Hsp70 concentration and oxidative damage. No changes in these parameters were exhibited by D. villosus or after a chronic exposure of G. jazdzewskii to predation cues. Our results show that prey organisms are able to reconfigure their physiology to maintain increased metabolic rate under prolonged predator pressure and, at the same time, reduce oxidative damage as well as costs related to anti-oxidant defence.

中文翻译：

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水生无脊椎动物对慢性捕食风险的适应性反应的实验证据。

由于捕食风险引起的急性应激会产生重大的氧化损伤，猎物有机体被迫平衡防御反应和激活细胞防御系统的成本。物种之间的胁迫耐受性差异很大；因此，捕食者的压力间接​​影响着群落结构。为了测试两栖类甲壳类动物（Dikerogammarus villosus和Gammarus jazdzewskii）的适应能力，我们将它们暴露于急性（35分钟）和慢性（1或7天）捕食风险（欧亚鲈鱼）中。我们测量了呼吸（与代谢率有关），细胞防御系统（抗氧化酶（过氧化氢酶）活性和热休克蛋白（Hsp70）浓度）和氧化损伤水平（硫代巴比妥酸反应性物质（TBARS）浓度）。两种食足动物在存在捕食线索的情况下均提高了呼吸频率，而与预先暴露于危险中的持续时间无关。比起贾兹热斯基（D. jazdzewskii），绒毛D.绒毛菌的增加开始得更快（与10分钟后立即相比），持续时间更长（20对10分钟）。但是，只有短时暴露于捕食风险后的贾氏假丝酵母表现出其过氧化氢酶活性，Hsp70浓度和氧化损伤的增加。这些参数没有出现变化，无论是D. villosus还是在G. jazdzewskii长期暴露于捕食线索之后。我们的结果表明，猎物有机体能够在延长的捕食者压力下重新配置其生理结构，以维持新陈代谢的速率，同时减少氧化损伤以及与抗氧化防御相关的成本。