Effects of 16-Day Fluoxetine and pCPA Exposure on the Velocity of the Invasive Crayfish Procambarus clarkii

Fluoxetine, a selective serotonin reuptake inhibitor (SSRI), is one of the most detected antidepressants in wastewater, managing to enter watersheds where it is taken up by freshwater fauna. Here we asked if the serotonergic system affects the locomotive capabilities of Procambarus clarkii, a prolific worldwide invasive crayfish species, thanks in part to its dispersal rates. For this, we exposed adult crayfish to 1 µg/L and 100 µg/L solutions of fluoxetine and para-chlorophenylalanine (pCPA, a tryptophan hydroxylase inhibitor) and measured their velocity after 8 and 16 days on a two-metre-long metal gutter. Overall, our treatment effects were revealed to be non-significant, suggesting P. clarkii has high tolerance to fluoxetine and pCPA and that at environmentally significant concentrations fluoxetine may not affect P. clarkii locomotion. Though our study was of limited scope and further research is needed with revised set-ups, these results can help us better understand the impact of ambient fluoxetine on this invasive species.