Use of chemical cues for shell preference by the hermit crab, Pagurus samuelis

Abstract

A series of experiments tested shell recognition ability of the hermit crab Pagurus samuelis. When presented with a choice between its original shell and another matched gastropod shell not previously inhabited by a hermit crab, P. samuelis chose its original shell. However, when a crab was presented with a choice between its boiled original shell and a boiled shell without prior hermit crab inhabitants, or the boiled shell of another crab, it lost its preference for its original shell. These experiments indicate that preference for the original shell by the crab is dependent on chemical, but not visual cues, and that these chemical cues are eliminated by boiling. In addition, P. samuelis displayed the ability to detect its original shell versus the shell from a conspecific. Crabs preferred their original shells. No difference was found in tests where a crab was given a choice between the scent of itself without a shell, and the scent of another shell‐less crab. This indicates that the cue for original shell preference is in some manner associated with the crab's shell.