Chemical Ecology and Social Behavior of Anomura

Abstract

Anomura is an extremely diverse assemblage of crustacean decapods with a large variety of forms and lifestyles, which makes the taxon ideal for comparative studies of social systems and means of communication. Notwithstanding this, our knowledge of Anomura is mostly restricted to the crab–shell relationships in hermit crabs, whereas promising fields of research, such as chemical ecology, are still in their infancy. This review will analyze the role played by chemical signals and cues in the social life of this taxon. Although our knowledge of anomuran chemical ecology is biased towards hermit crabs, we will illustrate the high potential of this taxon for complex chemosensory abilities. Case studies will be provided, showing that waterborne chemicals are used, for instance, to identify the sex of a potential mate in Pagurus geminus, to assess females’ reproductive state and fecundity by Pagurus filholi males, to select the higher-quality males in the lithodid Hapalogaster dentate, to attract Clibanarius vittatus, Pagurus longicarpus, and P. pollicaris to shell-recruitment sites, and to individually recognize conspecifics in P. longicarpus. Finally, we will discuss the directions to follow in the near future. Particularly, more scientific attention should be paid to unravel the identity of the substances involved in the transmission of information and to extend ecological studies to the still underexplored groups of lithodids, galatheids, and porcellanids.