Fluoxetine inhibits predator avoidance behavior in tadpoles

Fluoxetine is a selective serotonin re-uptake inhibitor used to treat anxiety and depression in humans. It has been detected as a contaminant in the surface waters in many countries. The effects of fluoxetine (0, 0.03, 0.3, and 3 mu g L-1) on the swimming and behavioral responses of Bufo arabicus tadpoles to alarm chemicals from predatory dragonfly larvae (Anax imperator) were measured. Fluoxetine significantly reduced swimming speed at 0.3 and 3 mu g L-1 in the absence of predator alarm chemicals but had no effect in their presence. Tadpoles exposed to predator alarm chemicals avoided open water and preferred to hide. Exposure to fluoxetine at 3 mu g L-1 completely eliminated this predator avoidance response, making the tadpoles more vulnerable to predation.