Exposure to Wastewater in the American Bullfrog Affects Feeding Behavior but not Activity or Baseline Corticosterone Levels

WESTMORELAND, KL*; MORENO, VN; SHAH, PJ; PHILLIPS, JD; SCOTT, NA; POWELL, LD; SOMLEY, BL; PROPPER, CR; Northern Arizona University; Northern Arizona University; Northern Arizona University; Northern Arizona University; Northern Arizona University; Northern Arizona University; Northern Arizona University; Northern Arizona University: Exposure to Wastewater in the American Bullfrog Affects Feeding Behavior but not Activity or Baseline Corticosterone Levels

Reclaimed water from wastewater treatment plants is screened for certain chemicals, but many do not yet fall under the screening regime. Some of these chemicals can interrupt the normal function of the vertebrate endocrine system by binding to hormone receptors and preventing many critical growth and physiological functions. In collaboration with the USGS, we evaluated reclaimed water from the Rio de Flag Treatment Plant in Flagstaff, Arizona for a broad range of potential chemicals. Then, in our lab we used in vivo and in vitro methods to test the hypothesis that Flagstaff reclaimed water does affect the behavior and endocrine function of the American Bullfrog (Rana catesbieana). Our studies highlight the effect of Flagstaff reclaimed water on the stress response. In vivo, the frogs were exposed to conditioned dechlorinated tap or wastewater for one month, and then the effect of the treatments on feeding behavior, activity, and interrenal activity were measured. We found that there was a statistically significant difference between the number of crickets eaten between the treated and control groups in the second feeding test (p=.0213) that occurred after 25 days of treatment. All other behavior and activity tests were not statistically significant. The baseline interrenal activity as measured by corticosterone levels in Rana catesbieana plasma was also statistically insignificant (p=0.3152) between treatments. These results suggest that although exposure to wastewater may influence feeding behavior, it may not produce this effect by influencing baseline levels of corticosterone.

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