Cardiidae
Cardiidae, commonly known as cockles, are a family of saltwater clams, marine bivalve mollusks in the order Cardiida. Cockles are generally small to medium-sized, with characteristically heart-shaped shells. They are found in a wide range of marine environments, from shallow intertidal zones to deeper waters, and have a global distribution.
Common Names
The common name "cockle" is derived from the Latin word "coclea", meaning "snail". The name is often applied to other bivalves, including species in the families Arcidae, Tellinidae, and Veneridae.
Characteristics
Cockle shells are typically heart-shaped or rounded, with prominent ridges or ribs radiating from the umbo (the hinge point of the shell). The shells are often brightly colored and may have intricate patterns. Cockles have a strong adductor muscle that allows them to close their shells tightly for protection. They also possess a muscular foot that they use to burrow into the sediment.
Environments
Cockles inhabit a variety of marine environments, including:
- Intertidal zones: Cockles are often found in shallow water, where they can be exposed to air during low tide.
- Subtidal zones: Cockles can also live in deeper water, where they are permanently submerged.
- Sand and mudflats: Cockles typically burrow into sandy or muddy substrates.
- Estuaries: Cockles can tolerate a wide range of salinity, making them well-suited to estuarine environments.