Copper mediates life history responses of Daphnia pulex to predation threat

A key challenge for ecological and ecotoxicological risk assessment is to predict the of organisms when exposed simultaneously multiple stressors in sub-lethal concentrations. Here, we assessed whether concentrations an anthropogenic stressors, heavy metal copper (Cu), mediates impacts a natural threat species, predation risk, among six distinct Daphnia pulex clones. We investigated interaction between two on morphological defenses several life-history traits including maturation time, size at maturity, somatic growth rate survival rates. Combining life table experiment response surface design, found no evidence that effects predator cue induced responses tested D. However, our data indicate can mediate risk. For age also clear observed varied by clones were strong or weak responders. Specific exploration relationship history under suggest hypothesis strategies deal with stressors. While interactions different make it harder their outcomes, ultimately assess water quality regulations about such study provides theory aid understanding predicting impacts.