Multimodal individual recognition in the crayfish cherax destructor

There is some evidence that macrurans recognize each other as individuals. In freshwater crayfish there are conflicting reports and there is limited information about the sensory mechanisms involved. To determine the extent to which the crayfish Cherax destructor is capable of individual recognition, we performed experiments that familiarized animals with each other and then manipulated their recent success in dominance contests. Crayfish were more likely to win an encounter when paired against a familiar opponent than an unfamiliar one after the manipulation stage. In other experiments, animals were attracted to familiar conspecifics when only visual or chemical cues were present. This demonstrates that C. destructor is able to discriminate between a familiar and an unfamiliar opponent. The results highlight the complex nature of intraspecific communication in crayfish and suggest elements likely to be of importance in the social interactions of groups in the wild state.