The Pagurus belongs to the Paguridae family. Hermit crabs are crustaceans with a curved and soft abdomen. It lives in empty shells of gastropods on which it sometimes attacks sponges or poisonous actinias to camouflage and defend itself. In case of danger it can withdraw completely inside the shell. The end of the tail of the hermit crab is suitable for strongly grasping the shell it always carries with it. When it grows and the size of the shell is no longer suitable is search for a new shell to protect yourself. In the video we see a hermit crab that has taken possession of the shell of the sea snail Phalium glaucum, a marine gastropod mollusc of the Cassidae family

Phalium glaucum, common name the grey bonnet or glaucus bonnet, is a species of large sea snail, a marine gastropod mollusk in the family Cassidae, the helmet snails and bonnet snails. This species lives on sandy bottoms with seagrass meadows, in intertidal and shallow subtidal areas to a depth of about 10 m. Shell of Phalium glaucum can reach a length of 60-147 millimetres.