The shell-acquisition behaviour of the bivalve-using hermit crab Porcellanopagurus nihonkaiensis Takeda, 1985 (Decapoda, Anomura, Paguroidea)
Keyword(s):
Almost all species of hermit crabs inhabit dead gastropod shells; however, species of some genera have evolved to inhabit bivalve or patelliform shells. It has been assumed that these species carry their shells using uropodal rasps and the hooked dactyls of their fourth pereopods, although no detailed description of the shell acquisition behaviour of those species has previously been documented. We have therefore observed the shell acquisition behaviour of Porcellanopagurus nihonkaiensis Takeda, 1985, which was collected by dredge at Shimoda, Shizuoka Prefecture, Japan. Our observation suggests that the shell is fixed in place by only the uropodal rasps in combination with hydrostatic pressure in the telson.