Publication
Psychoactive pollution suppresses individual differences in fish behaviour
Publisher:
The Royal Society
Date:
10-02-2021
DOI:
10.1098/RSPB.2020.2294
Abstract: 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 in iduals. 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 in iduals' activity, with in idual 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 in iduals to the overall decline in in idual variation. We found strong evidence that fluoxetine erodes variation in activity between but not within in iduals, revealing the hidden consequences of a ubiquitous contaminant on phenotypic variation in fish—likely to impair adaptive potential to environmental change.