Continuity of chronic predation risk determines changes in prey physiology

Area of Science:

• Ecology
• Environmental Science
• Animal Behavior

Background:

• Prey species often alter their physiology to mitigate the costs associated with sustained exposure to predators.
• The impact of intermittent or periodic predation risk on prey physiological adjustments remains less understood compared to constant risk.

Purpose of the Study:

• To investigate how the continuity of predation risk (constant vs. periodic) influences the physiological responses of two amphipod species.
• To assess the impact of predation risk on cellular defense systems, intracellular damage, and energy reserves in amphipods.

Main Methods:

• Exposure of Dikerogammarus villosus and Gammarus jazdzewskii to periodic and constant predation cues for one week.
• Measurement of total antioxidant status (TAS), heat shock proteins (Hsp70), lipid peroxidation (TBARS), and glycogen concentration.

Main Results:

• Predation risk reduced TAS in G. jazdzewskii and D. villosus (under periodic risk).
• Hsp70 was downregulated in D. villosus (periodic risk) and G. jazdzewskii (constant risk).
• TBARS levels decreased in D. villosus (all risk types) and G. jazdzewskii (periodic risk), while glycogen remained unaffected.

Conclusions:

• The continuity of predation risk significantly shapes prey physiological reconfiguration, optimizing costs under challenging conditions.
• Amphipods demonstrate resilience and can thrive under chronic predation risk, whether constant or periodic, highlighting their adaptability in natural environments.