Meeting Abstract
Animals must gather information from their environment to make decisions that maximize fitness and minimize injury and energy use. These decisions (i.e. assessment strategies) are especially important in the context of fighting behavior. The assessment strategy used by a particular species is dependent upon neural complexity as well as surrounding environmental factors (context). One such context is the ability of opponents to communicate effectively through various cues or signals. Degradation or absence of a signal can significantly alter contest dynamics, increasing fight times due to the inability to accurately assess oneself or an opponent. This study examined whether alterations in chemical communication affected the assessment strategy used by crayfish (Orconectes rusticus) by staging one-on-one contests. Mixed sex contests were randomly assembled and one individual was chosen to undergo lesioning, which impaired chemosensory abilities. Dyads were composed of either size matched opponents or opponents that differed in size (up to 30% difference in body length). Saltwater lesioning was used to lyse chemical receptors on the primary chemosensory organ while leaving mechanoreceptors intact. In order to elucidate mechanistic differences in the decision making paradigm (i.e. assessment strategy) for males and females, we compared the use of a quantifiable signal using chemical visualization techniques. Both individuals were injected with a fluorescent dye, and fights were observed under black lights. Trials were videotaped and analyzed for the type of assessment strategy in use as well as any differences in the timing or duration of signal release. Results indicate that blocking chemical communication appears to alter decision making in mixed sex crayfish contests.
