The mollusc (or mollusk) shell is typically a calcareous exoskeleton which encloses, supports and protects the soft parts of an animal in the phylum Molluscae, like snails, clams, tusk shells, and several other classes.
a one shelled mollusk
Gastropods, or slugs and snails, as opposed to molluscs with two shells which are bivalves.
A mollusk is a sea creature that lives within a shell. A cobra does not live in a shell.
THey use a shell
the function of the its shell is to protect the mollusk's very vulnerable and sensitive organs.
Every mollusk except slugs, which have evolved to not need a shell, has a shell. Snails, clams and other bivalves have an external shell. Octopi, squid and cuttlefish have an internal shell.
no
slug
yes
jellyfish
A shell
It is a shell, as in a cockle shell or oyster shell.