WOLF , Mary C; MOORE, Paul A: Orientation in Complex Sensory Landscapes: Spatial Arrangement of Odor Sources Modifies Orientation Strategies of Crayfish.

In natural aquatic systems organisms are presented with multiple food cues that are distributed in space and have to make decisions on how to respond to this plethora of information. Previous orientation work has relied on using one food odor stimulus where in natural habitats they are bombarded with multiple food information that can impact foraging decisions. The present study investigated how the spatial distribution of multiple food cues can affect crayfish orientation. Crayfish Orconectes virilis were presented with a series of food cues that were differentially spaced within an artificial stream. Orientation behavior was filmed from above and digitized one frame per second. In addition, electrochemical recordings were taken to characterize the structure and distribution of the odor plumes. Finally, an acoustic doppler velocimeter (ADV) was used to characterize the hydrodynamic structure of the artificial stream. Crayfish showed significantly altered orientation strategies when presented with different spatial arrangements of food cues. Since altering the spatial arrangement if the odor sources does not impact the hydrodynamics, any changes in orientation strategies indicates a chemotactic strategy as opposed to a rheotactic strategy.