Meeting Abstract
Animals living within aquatic habitats regularly encounter chemical pollution as a result of anthropogenic activities. Typically, the toxicity of chemical pollutant or toxins is determined by the median lethal concentration (LC50). However, LC50’s do not provide an accurate representation of exposure to a pollutant within natural systems. In their native habitats, animals experience exposure as a fluctuating concentration as a result of turbulent mixing. Edwards and Moore (2014) showed that more turbulent environments produce exposures with a high degree of fluctuation in frequency, duration, and intensity. In order to more effectively evaluate the effects of pollutants, we created a more ecologically relevant exposure paradigm, utilizing both natural flow and substrate within a small mesocosm. A commonly used pharmaceutical, naproxen, was used as the toxin and female Orconectes virilis crayfish as the target organism to investigate changes in fighting behavior as a result of dynamic exposure. Flow-through streams with a substrate mixture of gravel and sand were constructed for dynamic exposure trials, while aquarium tanks were used for static exposures. Crayfish underwent either a static or a dynamic exposure to naproxen in 23 hour long trials. Following exposure, the target crayfish and an unexposed size matched opponent underwent a 15 minute fight trial. These fight trials were recorded and later analyzed using a standard ethogram. Results indicate that exposure to sub-lethal concentrations of naproxen, in both static and flowing conditions, significantly alters aggressive behavior. Results also indicate a significant difference in behavior as a result of different exposure paradigms.
