Intraspecific Competition of Pagurus samuelis on Shell Selection and Recognition

Ariana A. Mortazavi


Marine hermit crabs use gastropod shells to protect their soft abdomens. By knowing a hermit crab’s shell preference, the dynamics of hermit crab interactions within a species can be better understood for shell selection and exchanges. This research conducted three treatments on the Pagurus samuelis hermit crab to test shell recognition ability and selection. The purpose of this experiment was to test intraspecific competition of P. samuelis on shell selection and recognition. The gastropod shells originally inhabited by the hermit crabs were all C. funebralis. P. samuelis females and males were presented with a choice of their original shell and another similar gastropod shell previously inhabited by a P. samuelis of the same sex. Overall, when tested individually, females preferred their own shell while males had no preference. However, when P. samuelis was presented the same shell choice in the presence of another hermit crab of the same sex, its preference changed. The location of the shell also mattered for the hermit crab’s shell choice. The experiments indicate that shell preference is dependent on the presence or absence of a conspecific of the same sex. Also, it was found that a P. samuelis hermit crab’s sex does make a difference in shell choice selection and preference.

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