When the living coral is underwater, it is brightly colored. Lots of soft heads called polyps are surrounded by tentacles. When they are disturbed, they escape into their hard skeleton. The corals breathe air through their skins and extract materials from the sea water to build their stony skeletons. Conch A conch has a hard shell that is shaped like a spiral.
Conches are different colors.
The conch uses its one foot to move across the bottom of the sea. Conch shells have many uses. Some conch shells are used to make buttons and cameos. The shell of an East Indian species is used as a horn. The egg cases of certain conchs look like leathery wafers strung on a cord.