Confusingly, the common name "cockle" is also given (by seafood sellers) to a number of other small edible bivalves which have a somewhat similar shape, however these bivalves are in other families such as the Veneridae (Venus clams) and the Arcidae (ark clams). Cockles in the family Cardiidae are sometimes known as "true cockles" in order to distinguish them from these other species.