Cockles are the family Cardiidae of bivalve mollusks.

The rounded shells are symmetrical, heart-shaped and feature strongly pronounced ribs. The mantle has three apertures (inhalant, exhalant, and pedal) for siphoning water and for the foot to protrude. Cockles typically burrow using the foot and feed by siphoning water in and out, sifting plankton from it. They are also capable of 'jumping' by bending and straightening the foot. Unlike most bivalves, cockles are hermaphroditic and reproduce quickly.

Cockles are a popular type of shellfish in both Eastern and Western cooking. Consumption of raw cockles has been linked to hepatitis. [1] Cockles are sold fresh as a snack food in the United Kingdom, and are eaten with vinegar. They are also available pickled in jars and, more recently, they are often sold in convenient sealed packets (with vinegar) containing a plastic two-pronged fork.

They are an effective bait for a wide variety of sea fishes.