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Research article - Peer-reviewed, 2021

Psychoactive pollution suppresses individual differences in fish behaviour

Polverino, Giovanni; Martin, Jake M.; Bertram, Michael; Soman, Vrishin R.; Tan, Hung; Brand, Jack A.; Mason, Rachel T.; Wong, Bob B. M.


Environmental contamination by pharmaceuticals is global, substantially altering crucial behaviours in animals and impacting on their reproduction and survival. A key question is whether the consequences of these pollutants extend beyond mean behavioural changes, restraining differences in behaviour between individuals. In a controlled, two-year, multigenerational experiment with independent mesocosm populations, we exposed guppies (Poecilia reticulata) to environmentally realistic levels of the ubiquitous pollutant fluoxetine (Prozac). Fish (unexposed: n = 59, low fluoxetine: n = 57, high fluoxetine: n = 58) were repeatedly assayed on four separate occasions for activity and risk-taking behaviour. Fluoxetine homogenized individuals' activity, with individual variation in populations exposed to even low concentrations falling to less than half that in unexposed populations. To understand the proximate mechanism underlying these changes, we tested the relative contribution of variation within and between individuals to the overall decline in individual variation. We found strong evidence that fluoxetine erodes variation in activity between but not within individuals, revealing the hidden consequences of a ubiquitous contaminant on phenotypic variation in fish—likely to impair adaptive potential to environmental change.


animal personality; behavioural plasticity; behavioural types; ecotoxicology; individuality; pharmaceuticals

Published in

Proceedings of the Royal Society B: Biological Sciences
2021, Volume: 288, number: 1944, article number: 20202294

        SLU Authors

        Sustainable Development Goals

        SDG14 Life below water

        UKÄ Subject classification

        Behavioral Sciences Biology

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