PH25 Wildlife Ecotoxicology II
Exhibit Hall
8:00 AM - Thursday
(PH304A) Maternal transfer of contaminants and its effect on embryonic development in the amphibian (Gastrophryne carolinensis).
Hopkins, W1, DuRant, S1, Staub, B1, Rowe, C2, Jackson, B1, 1 Savannah River Ecology Laboratory, Aiken, SC, USA2 Chesapeake Biological Laboratory, Solomons, MD
ABSTRACT- Although there is now general consensus that many amphibian populations around the globe are declining at alarming rates, the cause of most declines remains unknown. Environmental contamination is one of several factors implicated in declines, and may be particularly important for sensitive developmental life stages. Developmental pathways in embryonic amphibians can be altered when embryos are exposed to contaminants via two primary mechanisms, uptake from their surroundings (e.g., water) and transfer from mother to offspring. To date, no studies have examined maternal transfer of contaminants in amphibians, despite its devastating effects on development in every other major vertebrate lineage. Here, we examine maternal transfer of several elements, most notably selenium, in narrow mouth toads (Gastrophryne carolinensis). After collecting adults near a coal burning power plant, toads were bred under captive conditions and eggs reared for 96 hours in uncontaminated water. Toads utilizing the industrial area transfer significant quantities of contaminants to their eggs, but the effect of maternal transfer on offspring quality is not yet clear. In the 58 egg clutches examined to date, hatching success was 82 vs. 93% in the contaminated and reference site, respectively. Of the larvae that hatched, the frequency of developmental abnormalities was 17 vs. 11% and abnormal swimming frequency was 19 vs. 12% in the contaminated and reference site, respectively. Axial malformations (shortening, scoliosis, lordosis) were the most prevalent abnormalities observed. The results of our study demonstrate that maternal transfer may be an important route of contaminant exposure in amphibians and warrants future study.
Key words: selenium, malformations, amphibians, maternal transfer