Predation is an important structuring force in ecosystems and prey organisms developed a wide array of antipredator traits. Most attention went to behavioural, morphological and life history traits to deal with predators while physiological mechanisms involved in the defense against predators have been largely ignored. Physiological/molecular mechanisms may both play an intermediate role in shaping traditionally studied antipredator traits and also constitute end points on their own. In this project we study these physiological traits both by selecting a priori candidate molecules involved in immune function, oxidative defence and defence against protein degradation (Hsp60 and Hsp70) and by using an exploratory peptidomics approach. The study organisms will be damselfly larvae. By focusing on one genus with known phylogeny and repeatable changes in predator environment we can detect independent macroevolution of physiological antipredator traits.