Overview

Bivalvia is a class of marine and freshwater molluscs with laterally compressed bodies enclosed by a two-part hinged shell. They lack a head and a radula, and the majority are filter feeders. The class includes clams, oysters, cockles, mussels, scallops, and numerous other families found in saltwater and freshwater environments worldwide.

Origin and history

Bivalves have a fossil record dating to the early Cambrian period, over 500 million years ago. They have been harvested by humans for food since prehistoric times, with shell middens found on every inhabited continent. In Mesoamerica, bivalves such as clams and oysters were gathered along both the Pacific and Gulf coasts, and their shells were used for tools, ornaments, and lime production for nixtamalization. The Romans cultivated oysters in controlled beds, a practice that spread across Europe and later to the Americas.

Varieties and aliases

  • Clams (multiple families, including Veneridae and Myidae)
  • Oysters (family Ostreidae)
  • Mussels (family Mytilidae)
  • Scallops (family Pectinidae)
  • Cockles (family Cardiidae)
  • Geoducks (family Hiatellidae)
  • Razor clams (family Solenidae)

Culinary uses

Bivalves are eaten raw, steamed, grilled, fried, baked, or incorporated into soups and stews. Oysters are commonly served raw on the half shell with lemon, mignonette, or hot sauce. Mussels are often steamed in white wine, garlic, and herbs. Clams appear in chowders, pasta sauces, and steamed preparations. Scallops are typically seared or grilled. In Mexican coastal cuisine, clams and oysters are used in ceviches, tacos, and caldos such as caldo de almejas. Bivalves pair with acidic ingredients like lime, tomato, and vinegar, as well as garlic, butter, and chili.

Cross-cuisine context

Bivalves are a global ingredient with analogues across every cuisine represented on the platform. In Mexican cuisine, clams (almejas) and oysters (ostiones) are central to coastal dishes from Sinaloa, Baja California, and Veracruz. In Japanese cuisine, clams (hamaguri, asari) appear in miso soup and hot pots, and oysters (kaki) are eaten raw or fried. In Korean cuisine, clams (jogae) are used in soups like jogaetang and in grilled preparations. In Vietnamese cuisine, clams (nghêu) are steamed with lemongrass and chili. In Filipino cuisine, clams (tulya) and mussels (tahong) are cooked in sinigang and adobo-style dishes. In Peruvian cuisine, clams (conchas) and scallops (conchas de abanico) are key to ceviches and tiraditos. In Salvadoran and Guatemalan cuisine, bivalves are less central but appear in coastal seafood soups. In Arabic cuisine, clams and mussels are used in rice dishes and stews. In Armenian cuisine, bivalves are uncommon. In Russian cuisine, mussels and scallops appear in salads and soups. In Cambodian cuisine, clams are stir-fried with prahok and herbs. In Persian cuisine, bivalves are not traditional. No direct analogue exists for bivalves as a class, but individual species map to local equivalents in each cuisine.

Notes for cooks

  • Bivalves should be alive at time of cooking. Discard any with cracked shells or that do not close when tapped.
  • Store live bivalves in a breathable container in the refrigerator, not in sealed plastic or fresh water.
  • Cooking time is short. Overcooking produces tough, rubbery meat. Steam just until shells open.