FUNCTIONAL RELATIONSHIPS AMONG SELENIUM CONCENTRATIONS IN THE DIET, TARGET TISSUES, AND NONDESTRUCTIVE TISSUE SAMPLES OF TWO SPECIES OF SNAKES
WILLIAM A. HOPKINS,1 JOEL W. SNODGRASS,2 JENNIFER
A. BAIONNO,1 JOHN H. ROE,1 BRANDON STAUB,1
and BRIAN P. JACKSON1
1Wildlife
Ecotoxicology and Physiological Ecology Program, University of Georgia,
Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, South Carolina
29802, USA
2Department of Biology, Towson University, Towson, Maryland
21252, USA
(Received 17 November 2003; Accepted 12 July 2004)
Abstract-Nondestructive sampling methods, such as removal
of feathers for contaminant analysis, are desirable in ecological monitoring
programs that seek to minimize the impacts of harvesting organisms. Although
many reptiles are declining worldwide, nondestructive sampling techniques
seldom have been employed for assessing contaminant exposure in these
organisms. In this study, we examined the utility of nondestructive tissue
sampling for assessing Se exposure in reptiles. We describe the functional
relationships among dietary Se concentrations, target tissue Se concentrations,
and Se concentrationsm nondestructive tissue samples (blood and tail tissue
biopsy) in two species of snakes that had been exposed to Se under very
different experimental protocols. Using nonlinear regression, we found
strong positive correlations (r2 > 0.92) in all comparisons
among Se concentrations in nondestructive tissues, diet, and target tissues.
Moreover, equations describing these relationships can be used to estimate
concen- trations of Se in diet and target organs, from known concentrations
of Se in nondestructive tissue samples. Although the current paucity of
toxicity data on reptiles precludes tests of our models, we demonstrate
how the equations describing these relationships might be used to make
predictions about Se accumulation in target organs for risk assessment.
Future studies on reptiles that examine these relationships under different
Se exposure conditions, and those that document physiological responses
of reptiles to various concentrations of Se, will help to refine our models
and test their efficacy for predicting health risk.
Keywords-Selenium, Reptiles, Trophic transfer, Nondestructive
tissues, Risk assessment
SREL Reprint #2809
Hopkins, W. A., J. W. Snodgrass, J. A. Baionno, J. H. Roe, B. P. Staub and B. P. Jackson. 2005. Functional relationships among selenium concentrations in the diet, target tissues, and nondestructive tissue samples of two species of snakes. Environmental Toxicology and Chemistry 24:344-351.
