Common hermit crab

Way of life

More about the common hermit crab


Way of life

Hydroid polyps (Hydractinia echinata)

The hermit crab protects its soft and sack like abdomen by sticking it in an empty cone shell. Large hermit crabs live in empty whelk or neptunus shells, smaller individuals live in moon shells, common periwinkle shells or the shells of hinia nitida.
    The exterior of the shells are often covered with colony building hydroid polyps (Hydractinia echinata), which have stinging cells. When the hermit has outgrown its shell and needs a larger one, it will usually want to take its "pets" to the new shell. To accomplish this, the hermit crab gently strokes the hydroids with its claw. Eventually the hydroids became detached and can then be moved over to the new shell. When the hermit crab has moved into its new shell, the opening is closed with its large claw.

common hermit crab
Common hermit crab covered with hydroid polyps (Hydractinia echinata).

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