Inducible defensive traits of Daphnia pulex against predators are mainly determined by the offspring's environment rather than their mother's experience

Abstract

Predator-induced defence, a widespread phenomenon in ecosystems, is only expressed when individuals or populations of prey sense the pressure of predation (Tollrian & Harvell, 1999). It has been a major topic in ecological studies for a long time (Diel et al., 2020;Van Donk et al., 2011;Weiss, 2019). Inducible defensive traits are usually induced by chemical signals produced by predators (kairomone) or wounded prey (alarm signals), then other prey can sense these signals and respond to predators in time (Mitchell et al., 2017). This plasticity of inducible defences is beneficial for prey by protecting them from predators when predators are present, while avoiding the potential costs of defence expression when predators are absent (Westra et al., 2015).Previously, many studies have confirmed that prey individuals can express defensive traits in morphology, behaviour, physiology, and life history strategy when detecting predation signals. For example,