Feeding behaviour of fifteen species of hermit crabs (Crustacea : Decapoda : Anomura) from the Otago region, southeastern New Zealand

Abstract

Hermit crabs are common and conspicuous; members of intertidal and subtidal habitats. Although there exists an extensive literature on their behaviour, in the main this deals with :shell related behaviour :such as shell selection and shell fighting, and with behaviour patterns associated with the various symbiotic relationships of which hermit crabs form part (see the extensive bibliography in the recent review of hermit crab behavioural ecoloKv by Hazlett 1981). Other aspects of their behaviour have received much less attention . A number of studies on hermit. crab tee(ling behaviour have been made. However, relative to the number of living species (estimated at '" 700, Alcock 1905, Gordan 1956) very few have been investigated. Moreover, those species which have been studied to date all belong to genera of only two out of six families of marine hermit crabs (the Diogenidae and the Paguridae), and are intertidal or shallow water species. The feeding behadour of hermit crabs belonging to less well known families or genera or from less accessible habitats has not been studied. Nonetheless the available'data are sufficient to show that these animals have a wide range of feeding mechanisms including deposit-feeding, suspension-feeding, predation and scavenging. Often a species is able to feed in different ways depending on what food is available at the time (Kunze and Anderwn 1979, Schembri, 1982). Given such complexity of behaviour: (1 larger cross-section of species from a wider taxonomic range and from more diverse habitats needs to be investigated before evolutionary trends and adaptive radiation within the group can be studied. Sixteen species of hermit crabs belonging to four families are known to occur in the Otago region (table I; the late E. J. Batham unpublished data, C. L. ;McLay), personal communication) in habitats ranging from rocky intertidal through relatively coarse sediments of various sorts on the continental shelf to finer sediment:; on the continental shelf edge and slope. This rich fauna presented an ideal opportunity to study feeding in hermit crabs from a variety of taxonomic grouping and habitat types. Here the feeding behaviour and feeding mechanisms of 15 species of Otago hermit crabs are described and discussed in relation to their morphology habitat and previous work on feeding in hermit crabs.