Australian Land Hermit Crab - Shell Preference

Shell Preference

The preferred seashells of C. variabilis include Babylonia, Nerita, Phasianella, Thais, Tonna and Turban seashells. They are also found to be fond of several varieties of land snail shells such as Aratan snail and rice snail.

As the hermit crabs grow, they must exchange their shell for a larger one. Since intact gastropod shells are not an unlimited resource, there is frequently strong competition for the available shells, with hermit crabs fighting over shells. The availability of empty shells depends on the abundance of the gastropods and hermit crabs, but most importantly on the frequency of organisms that predate on gastropods but leave the shells intact. A hermit crab with a shell which is too tight cannot grow as fast as hermit crabs with well-fitting shells, and is more likely to be eaten. Although hermit crabs need to change shells regularly, they will not abandon their old shell unless they have a larger and newer one to change into and unless they feel safe.