Effects of Environmentally Relevant Concentrations of Sertraline on the Antipredator Behavior of Scinax fuscovarius Tadpoles

Sertraline is one of the most commonly detected antidepressants in surface waters, raising concerns on potential, non-intended effects on the behavior of non-target organisms. In this study we experimentally evaluate whether sertraline, at environmentally relevant concentrations, influences the behavior of prey in response to their predators. Our model system comprised tadpoles of the treefrog Scinax fuscovarius as consumers and larvae of the dragonfly Erythrodiplax as predators. This prey–predator system was exposed to sertraline concentrations of 0, 0.1, and 1.0 ug/L. We quantified tadpole activity rates, food intake rates, spatial avoidance, and hiding behavior, all of which are known to regulate predation risk. No main effects of sertraline were observed for any response variable; a main effect of predator presence was observed for spatial avoidance only. Most importantly, a significant sertraline-by-predator presence interaction term suggests that activity rates under the presence of predator is influenced by sertraline. We in addition quantified response variables related to swimming kinematics, which are also known to regulate predation risk. Tadpoles exposed to sertraline spent less time swimming, swam shorter distances, and required more stimuli to initiate swimming. Overall, our results suggest that environmental contamination by sertraline might influence larval amphibian behavior in ways that could afect their fitness.