Transgenerational Effects of Copper on a Freshwater Gastropod, Planorbella pilsbryi
Rebecca K Osborne, Patricia L. Gillis, Ryan S. Prosser
Abstract
Although much less common in ecotoxicology than traditional single-generation studies, multigenerational studies may offer a deeper understanding of the chronic and population-level effects caused by contaminants. To evaluate the potential utility of multigenerational contaminant studies and develop a feasible generational test design, we conducted a two-generational toxicity test using the freshwater File Ramshorn snail (Planorbella pilsbryi). Adults were exposed to five sublethal concentrations of copper, which resulted in significant delays in reproduction with increasing copper exposure and complete reproductive inhibition at the highest concentration (75.0 µg/L). Mortality and inhibition of reproduction were not observed in the control and three lowest concentrations (4.7, 9.4, and 18.8 µg/L Cu) over the course of the exposure and during recovery in clean water, indicating no lasting adverse effects. However, subsequent exposure of the unexposed juveniles that were produced during the recovery period (i.e. those not directly exposed to copper) showed that juveniles born to copper-exposed parents (LC50: 11.57 µg/L Cu; 95% CI: 3.71–19.43 µg/L Cu) were significantly less tolerant to copper exposure than juveniles born to unexposed parents (LC50: 29.25 µg/L Cu; 95% CI: 22.17–36.32 µg/L Cu). Despite no obvious changes in parental reproductive success, the fitness of unexposed juveniles was compromised due to parental exposure.