Malacology is the study of mollusks. These animals include snails, slugs, clams, mussels, octopus, squid, and many other kinds of animals without backbones that are often found in the sea, but sometimes in lakes and rivers, and on land. Most of them have shells, but not all of them. Some people save these shells because they may be very pretty. Many people eat mollusks, especially those people who live near the ocean.
Scientists study mollusks to learn how many kinds there are, where they are found, how they came to be as they are, and what their lives are like, as well as many other things about them. These scientists are called malacologists.