Investigating factors within the parental environment that influence the fitness of a freshwater gastropod species and their sensitivity to metal exposure
To effectively assess and manage the risks posed by chemicals in the environment, toxicological data must accurately represent the adverse effects that may occur in environmentally relevant exposure scenarios. An increasing weight of evidence suggests that certain chemicals can cause lasting adverse outcomes on populations long after the initial exposure had ended. These latent or transgenerational effects may alter the fitness of subsequent generations of organisms without direct exposure. To understand the influence of the parental environment, including exposure history, as a factor in offspring fitness and sensitivity to metals, the life history of the model gastropod Planorbella pilsbryi was thoroughly characterized. Organism sensitivity to metals was established and compared with the sensitivity of juveniles born to Cu-exposed parents. It was found that juveniles born to Cu-exposed parents were significantly more sensitive to subsequent Cu exposures than offspring born to unexposed parents. Mechanistic investigations of the bioaccumulation and direct maternal transfer of Cu indicated that maternal transfer of Cu to egg masses did correspond with trends in transgenerational effects. However, investigations of altered energy budgets and stress responses as mechanisms of the documented transgenerational effects were inconclusive.