Ecologically relevant arsenic exposure alters female mate preference and anxiety-like behavior in Betta splendens

Arsenic is a metalloid pollutant that is commonly found in surface and groundwater worldwide. Toxicological effects of arsenic are relatively well-known, but much less studied are its effects on behavioral endpoints, which may have considerable evolutionary and population-level consequences. Here we investigated the effects of exposure to environmentally relevant concentrations of arsenic (0, 10 and 100 μg/L) for 96-hours on female preference for male color (i.e. red versus blue) in Betta splendens, an increasingly popular fish model for contaminant-induced behavioral dysfunction. Further, we examined whether arsenic exposure altered anxiety-like behaviors using a standard scototaxis test (preference for light or dark), as well as measured tissue cortisol concentrations to increase our understanding of possible mechanisms driving behavioral responses. We found exposure to 100 μg/L arsenic results in a loss of female preference for red males, and arsenic exposed females showed increased anxiety-like behavior. The loss in preference for male coloration may have been driven by anxiety, as preference for red was negatively correlated with anxiety-like behavior for all fish. Interestingly, increase in anxiety-like behavior occurred without a parallel increase in cortisol. Female preference for red colored males may confer fitness benefits, and this study highlights important arsenic-induced behavioral changes that could have population level consequences.