Behavioral responses of northern crayfish (Faxonius virilis) to conspecific alarm cues and predator cues from smallmouth bass (Micropterus dolomieu)

Abstract

ABSTRACT While the ability for crayfish to detect visual and chemical cues is well documented, relatively few studies have probed the behavioral responses of crayfish to cues from key predators that they encounter in natural environments. Therefore, we examined how northern crayfish (Faxonius virilis) (Hagen 1870) responded to (1) alarm cues from conspecifics versus chemical cues from smallmouth bass (Micropterus dolomieu) (Lacepéde 1802), (2) varying concentrations of alarm cue from conspecifics, and lastly (3) smallmouth bass visual cues, chemical cues, and a combination of the two. We found that crayfish reduced walking activity in the presence of alarm cues. Chemical cues from smallmouth bass were also capable of eliciting a behavioral response, both alone and when paired with visual cues. Understanding the behavioral mechanisms by which crayfish respond to predatory fish is important to managing freshwater systems in the context of ongoing human- and climate-aided range expansions of both taxa.