Clams are bivalve mollusks that live in marine and coastal waters and are prized for their tender texture and mildly briny flavor. They are one of the most concentrated natural food sources of vitamin B12 and also provide high-quality complete protein, selenium, phosphorus, iron, choline, and the long-chain omega-3 fatty acids EPA and DHA. Clams can be steamed in their shells or purchased shucked for use in chowders, soups, pasta dishes, seafood stews, and other recipes. Because clams filter large volumes of water as they feed, sourcing them from clean, monitored harvesting waters is especially important.