Bivalves include all marine and freshwater mollusks with two shell-like plates hinged together by a muscle.  This group includes popular foods such as clams, mussels, scallops and oysters. They are commonly referred to as shellfish. However, bivalves should not be confused with crustaceans, another variety of shellfish including lobsters, crabs and shrimps.
When buying live bivalves, there are some rules to keep in mind about how to keep them alive, cook and eat them safely.
- Never buy a bivalve that's cracked or that won't close after you tap it.
- Store bivalves in the fridge in an open bowl WITHOUT water.
- Always brush and rinse bivalves clean (never use soap) before cooking and remove their beards if they have them.
- Cook bivalves within 24 hours of purchasing.
- Bivalves are ready to eat once they've opened during cooking. Overcooking will make them chewy.
- Never eat a bivalve that won't open during cooking.