Nicolaus Copernicus University, Faculty of Biology and Veterinary Sciences, Department of Invertebrate Zoology and Parasitology, Lwowska 1, 87-100, Toruń, Poland.
Nicolaus Copernicus University, Faculty of Biology and Veterinary Sciences, Department of Ecology and Biogeography, Lwowska 1, 87-100, Toruń, Poland.
Sci Rep. 2020 Apr 24;10(1):6972. doi: 10.1038/s41598-020-64000-9.
Prey reconfigure their physiology to avoid costs of prolonged predator pressure. However, these changes might not occur under periodic predation risk, with repeating acute phases. To test the effect of predation risk continuity on changes in prey physiology, we exposed amphipods: Dikerogammarus villosus and Gammarus jazdzewskii to periodic and constant predation cue. After one week, we measured: cellular defence systems: total antioxidant status (TAS), heat shock proteins (Hsp70); intracellular damage marker: lipid peroxidation (TBARS); condition index: glycogen concentration. Predator presence reduced TAS level in G. jazdzewskii independent of its continuity and in D. villosus after periodic exposure. Amphipods showed downregulation of Hsp70 when exposed to periodic (D. villosus) or constant (G. jazdzewskii) predation risk. Exposure to predators reduced TBARS level in D. villosus (irrespective of the continuity) and G. jazdzewskii (periodic exposure). Glycogen concentration in both species was not affected by predator presence. Thus, the continuity of the predator cue shaped prey physiology reconfiguration, optimizing costs of physiological adjustments under challenging conditions. Nevertheless, the lack of negative consequences of the prolonged exposure to the predator cue, whether constant or periodic, shows that amphipods can thrive under chronic predation risk, which is a constant part of the wild environment.
被捕食者会重新配置其生理机能以避免长期承受捕食压力的成本。然而，在周期性的捕食风险下，这些变化可能不会发生，因为周期性的捕食风险会反复出现急性阶段。为了测试捕食风险连续性对猎物生理变化的影响，我们让两种片脚类动物：Dikerogammarus villosus 和 Gammarus jazdzewskii 暴露于周期性和持续的捕食线索下。一周后，我们测量了以下生理指标：细胞防御系统：总抗氧化状态（TAS）、热休克蛋白（Hsp70）；细胞内损伤标志物：脂质过氧化（TBARS）；状况指数：糖原浓度。捕食者的存在降低了 G. jazdzewskii 的 TAS 水平，无论捕食风险是否连续，而 D. villosus 在周期性暴露后 TAS 水平也降低了。当暴露于周期性（D. villosus）或持续（G. jazdzewskii）捕食风险时，两种片脚类动物的 Hsp70 都出现了下调。暴露于捕食者会降低 D. villosus（无论连续性如何）和 G. jazdzewskii（周期性暴露）中的 TBARS 水平。两种物种的糖原浓度均不受捕食者存在的影响。因此，捕食者线索的连续性塑造了猎物生理机能的重新配置，在具有挑战性的条件下优化了生理调整的成本。然而，长期暴露于捕食者线索（无论是持续的还是周期性的）并没有带来负面影响，这表明片脚类动物可以在慢性捕食风险下茁壮成长，而慢性捕食风险是野外环境的一个恒定组成部分。
