Meeting Abstract

P2.90  Friday, Jan. 4  Exposure to an environmentally relevant stressor alters whole body corticosterone, oral morphology, growth, and development in larval Southern Leopard Frogs throughout metamorphosis. PETERSON, J.D.; MENDONCA, M.T.*; Auburn University; Auburn University mendomt@auburn.edu

Coal combustion residues (CCR), derived from coal burning power plants, have become a major global pollutant. In the US, 57 million tons of CCR, containing high concentrations of contaminants, are released into aquatic settling basins, habitats frequently used by local wildlife. These contaminants can pose as sub-lethal stressors and potentially affect amphibian physiology and development. Experimental studies that have exogenously manipulated corticoids (hormones linked with stressors) have found that this treatment can influence oral morphology, growth, and development but there have been few studies to date that have explored the relationship of endogenous corticoid levels on these parameters. In the current study, we exposed larval Southern Leopard Frogs to CCR, an environmentally relevant stressor, throughout metamorphosis to observe effects on endogenous corticosterone, oral morphology, growth, and development. Whole body corticosterone concentrations were significantly elevated in tadpoles exposed to CCR at key developmental stages throughout metamorphosis. Ninety percent of the CCR-exposed tadpoles displayed oral abnormalities, while no control individuals displayed abnormalities. Tadpoles raised on CCR sediment took significantly longer to reach and were significantly smaller in body size at all developmental stages, on average, when compared to controls. Our study is the first to show that an environmentally relevant stressor can influence endogenous corticoid secretion during amphibian metamorphosis. Furthermore, this increased secretion of corticosterone may mediate the oral abnormalities, retarded growth, and delayed metamorphosis that we observed.