Methods:
The purpose of this project is to determine potential differences in the reliance on a chemical signal (compared to visual or tactile information) under different contexts. Dyadic contests will be staged based on a 3 x 2 design. I will utilize three sensory block treatments (visual block, chemical block, tactile block) for different size treatments (size matched or size different) for male intrasexual contests. Prior to the contest, individuals will be injected with fluorescent dye (fluorescein) in order to visualize urine release. Black lights will be used to assist with the visualization of the fluorescent dye/urine solution released during the contest. For each contest, frequency and duration of urine release will be measured and each release time point will be paired with a behavior determined by an ethogram (Bergman & Moore, 2003). All animals used will be crayfish (Orconectes rusticus) collected from Maple Bay (Burt Lake). Due to the injection of foreign material and housing conditions that differ from natural conditions, all animals will be frozen at the conclusion of this project. Animals will be housed in flow-through troughs at the Lakeside Lab Research Facility and will be placed in individual containers within the troughs in order to eliminate social interactions prior to contests. All experiments will take place within the Lakeside Lab Research Facility as a completely darkened room will be necessary for urine visualization during contests.