Meeting Abstract

71.6  Monday, Jan. 6 09:15  Atrazine and metolachlor exposure affects the chemosensory responses of male crayfish (Orconectes rusticus) to female odors BELANGER, R.M.*; SABHAPATHY, G.S.; KHAN, S.; University of Detroit Mercy; University of Detroit Mercy; University of Detroit Mercy belangra@udmercy.edu

The presence of environmental pollutants is known to have an effect on olfactory-mediated behaviors in aquatic animals. Exposure to the herbicides atrazine and metolachlor has been shown to affect important chemosensory behaviors in crayfish. Male crayfish rely on the presence of chemical signals, released from reproductively active females, in order to locate those females for mating purposes. In this study, we exposed form I (reproductive) male crayfish to ecologically relevant, sublethal levels of atrazine (80 ppb), metolachlor (80 ppb), an atrazine and metolachlor mixture (80 ppb of each) and water only (control) for 96 hours. We analyzed the behavioral reactions of herbicide-treated and control male crayfish to two different odor sources: reproductive female-conditioned water or water (control) delivered from one end of a test arena. We measured odor localization and locomotory behaviors of male crayfish in response to female odors and water (control) from all treatments. Crayfish that were not exposed to the herbicides spent more time closer to a reproductive female odor source, whereas crayfish in all herbicide exposure treatments showed no preference for the female odor. Further, control crayfish had an increased walking speed (cm/s) when female odor was present in the test arena. Male crayfish treated with atrazine and metolachlor demonstrated lower walking speeds when female odor was delivered. We conclude that sublethal concentrations of atrazine and metolachlor interfere with the ability of crayfish to receive or respond to reproductive signals which may negatively affect population growth in the ecosystems they occupy.