Exposure to an environmental estrogen breaks down sexual isolation between native and invasive species

Authors

  • Jessica L. Ward,

    Corresponding author
    1. Department of Fisheries, Wildlife and Conservation Biology and Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN, USA
    Current affiliation:
    1. Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN, USA
    • Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA
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  • Michael J. Blum

    1. Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA
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Correspondence

Jessica Lyn Ward, Department of Ecology and Evolutionary Biology, University of Minnesota, 1987 Upper Buford Circle, Saint Paul, MN, 55108, USA.

Tel.: +1 504 941 0899;

Fax: +1 612-624-6777;

e-mail: jlward@umn.edu

Abstract

Environmental change can increase the likelihood of interspecific hybridization by altering properties of mate recognition and discrimination between sympatric congeners. We examined how exposure to an environmentally widespread endocrine-disrupting chemical (EDC), bisphenol A (BPA), affected visual communication signals and behavioral isolation between an introduced freshwater fish and a native congener (genus: Cyprinella). Exposure to BPA induced changes in the expression of male secondary traits as well as male and female mate choice, leading to an overall reduction in prezygotic isolation between congeners. Changes in female mate discrimination were not tightly linked to changes in male phenotypic traits, suggesting that EDC exposure may alter female choice thresholds independently of the effects of exposure on males. These findings indicate that environmental exposure to EDCs can lead to population declines via the erosion of species boundaries and by promoting the establishment and spread of non-native species via hybridization.

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