title: The psychoactive pollutant fluoxetine compromises antipredator behaviour in fish.
abstract: Pharmaceuticals are increasingly being detected in aquatic ecosystems worldwide. Particularly concerning are pharmaceutical pollutants that can adversely impact exposed wildlife, even at extremely low concentrations. One such contaminant is the widely prescribed antidepressant fluoxetine, which can disrupt neurotransmission and behavioural pathways in wildlife. Despite this, relatively limited research has addressed the behavioural impacts of fluoxetine at ecologically realistic exposure concentrations. Here, we show that 28-day fluoxetine exposure at two ecologically relevant dosages-one representing low surface water concentrations and another representing high effluent flow concentrations-alters antipredator behaviour in Eastern mosquitofish (Gambusia holbrooki). We found that fluoxetine exposure at the lower dosage resulted in increased activity levels irrespective of the presence or absence of a predatory dragonfly nymph (Hemianax papuensis). Additionally, irrespective of exposure concentration, fluoxetine-exposed fish entered the predator 'strike zone' more rapidly. In a separate experiment, fluoxetine exposure reduced mosquitofish freezing behaviour-a common antipredator strategy-following a simulated predator strike, although, in females, this reduction in behaviour was seen only at the lower dosage. Together, our findings suggest that fluoxetine can cause both non-monotonic and sex-dependent shifts in behaviour. Further, they demonstrate that exposure to fluoxetine at environmentally realistic concentrations can alter antipredator behaviour, with important repercussions for organismal fitness.
authors.affiliation: School of Biological Sciences, Monash University, Victoria, Australia. Electronic address: jake.martin@monash.edu.
authors.forename: Jake M
authors.initials: JM
authors.lastname: Martin
authors.affiliation: School of Biological Sciences, Monash University, Victoria, Australia; Environmental and Marine Biology, Åbo Akademi University, Turku, Finland.
authors.forename: Minna
authors.initials: M
authors.lastname: Saaristo
authors.affiliation: School of Biological Sciences, Monash University, Victoria, Australia.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Bertram
authors.affiliation: Centre for Environmental Sustainability and Remediation, RMIT University, Victoria, Australia.
authors.forename: Phoebe J
authors.initials: PJ
authors.lastname: Lewis
authors.affiliation: Centre for Environmental Sustainability and Remediation, RMIT University, Victoria, Australia.
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Coggan
authors.affiliation: Centre for Environmental Sustainability and Remediation, RMIT University, Victoria, Australia.
authors.forename: Bradley O
authors.initials: BO
authors.lastname: Clarke
authors.affiliation: School of Biological Sciences, Monash University, Victoria, Australia.
authors.forename: Bob B M
authors.initials: BBM
authors.lastname: Wong
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000633:toxicity*; D003532:Cyprinodontiformes / Q000502:physiology*; D004781:Environmental Exposure; D005260:Female; D005473:Fluoxetine / Q000633:toxicity*; D007313:Insecta; D008297:Male; D011235:Predatory Behavior / Q000187:drug effects*; D012737:Sex Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000928:Antidepressive Agents; D014874:Water Pollutants, Chemical; D005473:Fluoxetine
keywords: Antidepressant; Antipredator behaviour; Fluoxetine; Gambusia holbrooki; Non-monotonic; Pharmaceutical pollution