|Title||Behaviorally-selective chemoreceptor lesions reveal two different chemically mediated orientation strategies in the rusty crayfish, Orconectes rusticus|
|Publication Type||Journal Article|
|Year of Publication||2015|
|Authors||Kraus-Epley KE, Lahman SE, Moore PA|
|Journal||Journal of Crustacean Biology|
|Pagination||753 - 762|
Information from environmental stimuli is essential for animals to make behaviorally and ecologically relevant decisions. We sought to determine by studying Orconectes rusticus(Girard, 1852), the relative importance of mechanical and chemical information during orientation of crayfish to food and the type of orientation strategy crayfish employ to locate attractive odor sources. This was achieved through selectively lesioning chemoreceptors, leaving mechanoreceptors intact. Chemoreceptors were lesioned by placing the olfactory appendages in 50 ppt saltwater for two hours, then a deionized water bath for 10 minutes. Crayfish were subsequently used in orientation trials with a food source of fish gelatin. Orientation videos were digitized and orientation parameters (walking speed, heading angles and turning angles) were analyzed at a population level using a polynomial regression to determine how parameters changed as a function of distance from source and experimental treatment. Through the lesioning of chemoreceptors, we determined whether crayfish were orienting using chemotaxis or odor-gated rheotaxis. Lesioned crayfish oriented to the source with significantly decreased upstream heading angles compared to controls. Regression analysis revealed that lesioned crayfish had significantly altered orientation parameters demonstrating a change in orientation strategy. Results suggest that intact crayfish are using chemical information to guide search behavior while lesioned crayfish are performing a rheotactic-type of search.