(full paper is archived in the Miller Library)
Title: A symbiotic relation between intertidal hermit crabs and sea anemones
Student Author(s): Yates, Gaylan Dean
Faculty Advisor(s): Abbott, Donald P.
%E Baxter, Charles
Location: Final Papers Biology 175H
Date: June 1980
Keywords: symbiosis at the seashore
Abstract: The hermit crabs Pagurus samuelis and Pagurus granosimanis live in close association with the sea anemones Anthopleura xanthogrammica and A. elegantissima in the intertidal region at Hopkins Marine Station. The crabs are often observed walking on the columns and tentacles of the anemone without any response from the nematocysts. This appears similar in many ways to the relationship established betweem the tropical anemone fish and their hosts. The hermit crabs go through a sequence of behavior in which they acquire a coating of mucus from contact with the anemone. The mucus is acquired through a series of behavioral steps exhibited by the crabs: poking, brushing, and stroking the anemone. Once acclimated, the crab freewalks among the tentacles feeding off of small food particles stuck to the Anthopleura and even removing food from the gut of its host. The protective mucus coat gradually loses its effectiveness if the hermit crab is isolated from anemones. This is a symbiotic relationship benefiting the crabs by providing a source of food and protection from a potential predator.