Octopuses, snails, slugs, oysters, clams, scallops, squids, and a number
of similar creatures all belong to a “family” of animals called mollusks
[(mahl]{.smallcaps} uhsks). The name means “soft body.”
A mollusk has no skeleton. But most mollusks do have some kind of shell
that gives them protection. Their shells are the “sea shells” so often
found on beaches.
Some mollusks never move. But most have a sort of thick pad on which
they can crawl very slowly. Other mollusks, such as squids and
octopuses, have snaky arms instead of a pad. And most mollusks have a
very special sort of tongue, one that is different from the tongue of
any other animal. It is like a ribbon that is covered with tiny teeth. A
mollusk uses its tongue like a file.
There are more than eighty thousand different kinds of mollusks. Each
kind of mollusk that has a shell has its own special kind of shell.
People who collect and study sea shells can often look at a shell and
tell what kind of mollusk lived in it.
octopus