Affiliation: | (1) Department of Biology, Minnesota State University Moorhead, Moorhead, MN, 56563, U.S.A.;(2) College of Biological Science, Univeristy of Minnesota , Saint Paul, Minnesota, 55113, U.S.A. |
Abstract: | Synopsis Fishes in the superorder Ostariophysi possess specialized epidermal cells that contain a chemical alarm cue. The alarm cue is released when the skin is damaged during a predatory attack. Therefore, the cue serves as a reliable indicator of predation risk to nearby conspecifics and ecologically similar heterospecifics with which it shares predators. Antipredator behavior in response to these alarm cues has been demonstrated in numerous studies in confined spaces (laboratory aquaria, field traps, fluvarium). When tested on a natural field population however, behavioral response has been inconsistent. Here, we expose free-ranging redbelly dace and fathead minnows to skin extract of redbelly dace and record their behavioral response with an underwater video camera. We observed avoidance of areas in which skin extract was introduced, but no avoidance of areas in which water (control) was introduced. These data confirm the ecological function of skin extract in mediating predator–prey interactions in aquatic habitats, and argue against the hypothesis that alarm reactions are an artifact of confined spaces. |