Mercenaria mercenaria, commonly known as the hard clam or quahog, is a species of clam found along the eastern coast of North America. These bivalve mollusks inhabit sandy and muddy substrates in coastal waters, where they burrow into the sediment. They are known for their robust, rounded shells, which can vary in color from gray to brown. Hard clams are an important part of the marine ecosystem and are also significant in commercial fisheries. They are harvested for food and are often used in various dishes, including chowders and stews. Their growth and reproduction are influenced by environmental factors such as temperature and salinity.