Perception of alarm cues influences the outcome of shelter competition in crayfish20

Abstract

The effects of predators on prey populations may significantly alter many aspects of prey biology, including spatial distribution, foraging activities, and social interactions. In aquatic habitats, chemosensation is an important mode of communication and has been shown for many taxa, including crayfish, to be used in detection of predator and/or conspecific alarm cues. Here, we report on an experiment to test the hypothesis that detection of alarm cues results in greater individual investment in contests over shelters. We tested this hypothesis through dyadic contests between sex‐ and size‐matched, non‐reproductive individuals of Faxonius virilis. We found that crayfish responded to exposure to alarm cues by spending more time inside a shelter. We also report that in contests between pairs in which one crayfish had been exposed to alarm cues and the other had not, exposed individuals were significantly more likely to win ownership of a single shelter. However, we did not detect any differences in the contest parameters we recorded between exposed and unexposed crayfish. These impacts on both individual and social behavior indicate that the presence of predators is likely to have large effects on the distribution and structure of crayfish populations.

Are you scared yet? Variations to cue indices elicit differential prey behavioral responses even when gape-limited predators are relatively small

“…However, some organisms rely most heavily on one sensory modality to make relevant decisions. For instance, in aquatic systems, crayfish primarily use chemical signals and cues to navigate habitats (Callaghan et al 2012;Driscoll et al 2020). Crayfish have evolved a highly sensitive chemosensory system that allows for the detection of predators in dark waters where visual cues may be unhelpful and less accurate and have been established as ecosystem engineers as well as keystone species (Jones et al 1994;Statzner et al 2000;Creed and Reed 2004;Usio and Townsend 2004;Wright and Jones 2006).…”