Aquatic Hermaphrodite Snails Exposed to Polychlorinated Biphenyls (PCBs) Experience Increased Mortality, Reduced Reproduction, and Endocrine Disruption

Abstract

Populations of freshwater gastropods are decreasing globally. To investigate one aspect of decline, we exposed the benthic dwelling hermaphroditic snail Planorbella (= Helisoma) trivolvis (Say) (Marsh Rams-horn) to polychlorinated biphenyls (PCBs). Marsh Rams-horn is a simultaneous hermaphrodite, suggesting that disruption of reproductive success is independent of snail interaction and more dependent on internal controls. We examined the impact of exposure to PCBs on mortality, reproductive success, and tissue hormone concentrations. Exposure to Aroclor®1254 in concentrations found in natural habitats caused higher mortality and reduced reproductive success. Additionally, tissue estrogens were significantly elevated while testosterone remined unchanged in PCB-exposed snails. Given the importance of hermaphroditic freshwater gastropods in ecosystems, worldwide population decline, and ubiquity of PCBs, identifying the impact of exposure informs our ability to combat population loss.