PHILLIPS, J. D.; * SCOTT, * N. A.; * POWELL, * L.D.; * PROPPER, * C. R.; Northern Arizona University: J.D. Phillips, N. A. Scott, L. D. Powell, and C.R. Propper. Exposure to Rural Metropolitan Reclaimed Wastewater Reduces the Number of Days to Undergo Metamorphosis in Xenopus laevis jdp24@dana.ucc.nau.edu

As the demand for water in the United States continues to rise, local authorities look to ease the demand by utilizing reclaimed wastewater (WW) for irrigation, construction, and a host of other uses. However, its use may pose an avenue for endocrine disrupting compounds (EDCs) to enter our environment as many EDCs have been found in WW downstream from treatment plants. We used the African-clawed frog as a biosensor to determine whether Flagstaff reclaimed WW has endocrine disrupting potential. More specifically, we determined the effects Flagstaff reclaimed water has on the sexual differentiation and metamorphosis. The experimental design consisted of two control groups (FETAX and conditioned water with ion concentrations similar to Flagstaff WW) and a reclaimed WW exposure group. Freshly ovoposited eggs from 3 mated pairs were placed in control or wastewater aquaria tanks (6 L/tank; 3 tanks/treatment; 30 animals/tank; total N/treatment = 90). Weekly, 12 animals from each group were removed and stage of development, mass, and total length were determined. Following metamorphosis the animals were sacrificed and gonads were extracted for future sexual analysis. Individuals from the experimental group underwent metamorphosis in fewer days, weighed less, and were shorter than the individuals from the control groups. The characteristics observed in the reclaimed animals supports the hypothesis that the WW contains EDC�s that my act as thyroxin or may alter hypothalamic-pituitary-thyroid activity. The reduced time until metamorphosis and the resulting morphologic changes in size at metamorphosis indicate that WW exposure influences endocrine directed development in this aquatic species.