Clams live in both salt water and fresh water. Most clams are found in shallow water in areas that are muddy or sandy. However, there is a particular species known as Abra profundorum, which can be found in the Pacific Ocean at depths of up to 16,000 feet.
Clams are invertebrates with a bivalve shell. This means that their shells are equal in size and closed together with two adductor muscles. They also have a muscular foot that they use to burrow themselves in the mud. Burying themselves offers protection against wave activity and predators. Clams can be found in a variety of sizes ranging from 0.004 of an inch to almost 4 feet as seen in the giant clam, which is found in both the Pacific and Indian oceans.