Meeting Abstract

P3.140  Tuesday, Jan. 6  Anthropogenic Chemicals Adversely Affect Predator Avoidance Behavior of Larval Fish MCGEE, MR; SCHOENFUSS, HL*; St. Cloud State University, MN hschoenfuss@stcloudstate.edu

When aquatic organisms are exposed to common anthropogenic chemicals, how will that exposure affect innate survival behaviors? To investigate this question, short-term exposures (12 days) subjected larval fathead minnows Pimephales promelas to environmentally relevant concentrations of chemicals, singular or in mixture, from the following two classes: (1) estrogens or (2) anti-depressant pharmaceuticals. Following exposure, larvae were introduced to a simulated threat stimulus (standardized vibration). Under normal circumstances during a predator-prey confrontation, larval fish use an escape response, the C-start, to rapidly move away from an approaching threat. The C-start has been extensively studied and a neuro-anatomical axis of sensor-Mauthner cell (neuron; CNS)-effector has been identified. This behavior is also conserved across teleost lineages, and the inability to effectively execute a C-start has direct adversary consequences. High-speed (1,000 Hz) video recordings of larval C-start performances were collected for frame-by-frame analysis of latency periods, escape velocities, and total escape response. Both chemical classes adversely affected larval total escape response; however, they exhibited different modes of action. Estrogen exposure significantly affected larval latency periods (up to 60% longer to react); antidepressant exposure affected larval escape velocity (up to 63% slower). Our findings suggest that anthropogenic chemicals have the ability to influence larval escape performance through multiple modes-of-action. Further studies will explore the molecular alterations on the Mauthner cell axis caused by these chemical exposures. EPA STAR (R832741-01-0).