title: Counterbalancing effects of maternal mercury exposure during different stages of early ontogeny in American toads.
abstract: Maternal transfer of environmental contaminants is a disadvantageous parental effect which can have long-lasting implications for offspring fitness. We investigated the effects of mercury (Hg) on the reproductive success of female amphibians and the subsequent effects of maternal transfer on the development of their offspring. American toads (Bufo americanus) maternally transferred Hg to their eggs, and there was a negative relationship between Hg concentrations and the percentage of viable hatchlings produced in clutches. However, when we continued to monitor larvae that successfully hatched, we found 21% greater metamorphic success in larvae from Hg-exposed mothers compared to reference larvae. The negative effect in the embryonic stage and positive effect in the larval stage counterbalanced one another, ultimately resulting in no difference in predicted terrestrial recruitment, regardless of maternal Hg exposure. Our findings demonstrate that maternal effects on survival manifesting at different stages in ontogeny have the potential to produce complicated outcomes.
authors: Wildlife Ecotoxicology and Physiological Ecology Program, Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, VA 24061, USA.
authors: Christine M
authors: CM
authors: Bergeron
authors: William A
authors: WA
authors: Hopkins
authors: Catherine M
authors: CM
authors: Bodinof
authors: Sarah A
authors: SA
authors: Budischak
authors: Haruka
authors: H
authors: Wada
authors: Jason M
authors: JM
authors: Unrine
mesh_terms: D000818:Animals; D002025:Bufonidae; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D005298:Fertility / Q000187:drug effects*; D007814:Larva / Q000187:drug effects; D018811:Maternal Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D008628:Mercury / Q000633:toxicity*; D008675:Metamorphosis, Biological / Q000187:drug effects*; D010063:Ovum / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D008628:Mercury