Non-Lethally Produced Chemical Risk Cues Elicit Antipredator Responses in a Common Canadian Minnow

Abstract

Predation risk exerts significant pressure on the survival of prey species and has many indirect impacts on their habitat use, energy allocation, and community dynamics. Prey must consistently assess their surroundings by using multiple information sources to monitor predation risk and respond accordingly. In aquatic environments, chemical signals (i.e., alarm cues, disturbance cues, and predator odors) play a crucial role in informing prey of predation risk. Here, we systematically assess the impact of two non-lethal cues, disturbance cue and predator odor, on four aspects of prey fish behavior using the common blackchin shiner (Miniellus heterodon), a possible surrogate species for the Threatened pugnose shiner (Miniellus anogenus). In experiment 1, we found that conspecific disturbance cue elicited an increase in activity relative to the controls. However, there were no changes in area use, shoaling, or shelter use. In experiment 2, we found that predator odor elicited increased shelter use in blackchin shiner, consistent with an antipredator strategy, but no changes in activity, area use, or shoaling. Our two experiments suggest that disturbance cues and predator odors elicit different behavioral responses in blackchin shiner, perhaps since sources of risk information vary in their urgency and reliability. These results aimed to provide the baseline for future work on pugnose shiner, and demonstrate the value of using non-lethal chemical cues, with standardized methods, to study antipredator behavior in threatened species.