Sunbathing will make you lighter. New behaviour observed in an intertidal hermit crab

Abstract

Hermit crab behaviour has been widely studied, including aspects related to reproduction, olfactory attractants, association with other species, daily movements and migrations, clustering and, profusely, shell selection and utilization (Bertness, 1980, 1981; Hazlett, 1981; Gherardi & Vannini, 1989; Gherardi, 1990; Gherardi et al., 1991; Turra & Leite, 2000; Calado et al., 2006). Studies have focussed mainly on the intertidal zones, because of both accessibility and the role that this changing environment plays in behavioural adaptations. Intertidal species have to have physiological tolerance to extreme changes of salinity, temperature and air exposure in short periods of time. Also, the intertidal habitat is a high-risk zone, because of predation from marine and terrestrial predators (Vanini & Chelazzi, 1985). Hermit crabs are one of the most successful groups in the intertidal zone, probably due to the shell association that provides them with movable shelter, offers protection from physical stress and helps to maintain micro-climatic conditions (Reese, 1969; Hazlett, 1981). Shells also play an important role in the social structure of hermit crabs (Hazlett, 1966; Gherardi et al., 1994). The dependence association between hermit crabs and shell has strongly extended into almost all aspects of their biology (Hazlett, 1981); for this reason there are numerous works studying the relation between hermit crabs and gastropod shells and the behaviour related with shell selection and utilization (García & Mantelatto, 2001 and references herein).