Responses of hermit crabs to hemolymph from conspecifics and heterospecific crustaceans

Previous studies indicate that hermit crabs may use the blood or hemolymph from dying crabs to locate the soon-to-be-vacated shells. In this study, I determined and characterized the responses of hermit crabs to hemolymph from various crustaceans. Hermit crabs tested included members of the Diogenidae: Dardanus venosus, Clibanarius tricolor, C. antillensis, C. vittatus, and Calcinus tibicen; and Paguridae: Pagurus longicarpus and P. annulipes. Test odor sources included the previously mentioned hermit crabs plus seven additional odors, including three non-anomuran crustaceans. Most significant responses to hemolymph were to species within the same family. In several cases, the strongest responses were to conspecifics or congenerics. These results show clearly that hermit crabs in general use chemicals from other hermit crabs as cues for finding new shells. These results also show that the shell a crab occupies influences its response to odors, illustrating the role of context in these interactions.