What is "dog cockle"

The dog cockle or European bittersweet, Glycymeris glycymeris, is a species of marine clam, a coastal bivalve mollusc of European waters.

Despite its common name, it is not closely related to the common cockle.

While the English common name "dog cockle" implies an inferior food that might only be suitable for animals, this shellfish is edible and enjoyed in many European countries, although the flesh has a reputation for becoming tough if overcooked. Its name in French (amande de mer) and Spanish (almendra de mar) means "sea almond", due to its apparently sweet and almond-like flavour.