Social Recognition in Hermit Crabs

Abstract

The types of social recognition shown by hermit crabs are reviewed. Three aspects of hermit crab behavioral ecology that are important in social recognition are discussed. First, movement patterns can increase the probability of repeated interactions between individuals, thus increasing the possibility of social recognition based on past experience. Second, the phenomenon of individuality and consistency in the execution of behaviors is a necessary feature for individual social recognition. And finally, the evidence for dominance hierarchies in hermit crabs and the linkage to social recognition are considered. The experimental evidence for social recognition in hermit crabs is reviewed. While most studies have demonstrated just binary or class recognition (e.g., familiar versus non-familiar), the work of Gherardi and coworkers provide good evidence for possible true individual recognition in the hermit crab Pagurus longicarpus. The special considerations arising from the use of gastropod shells for protection by hermit crabs are discussed as they relate to aspects of social recognition.