Shellfish is a culinary term that is often used for several species of molluscs, gastropods, bivalves and arthropods. Some examples are the St. James shell, mussels, razor clams, oysters, cockles and whelks. Most shellfish live partly or fully buried into the seabed, mostly in sandy or gravelly bottoms. They feed by filtering nutrients out of the water. Seed and eggs are released into the water and fertilized externally. Most shellfish are hermaphroditic, they can be both male and female. There are many different shellfish species in the North Sea that are very much suitable for consumption. Fishing methods on shellfish include hand-picking, dredging or mechanic dredges (suckers).
The whelk is a large, edible sea snail. This species is very common in the North Atlantic Ocean, some Arctic islands and North America. This species is particularly common along the coasts of north-western Europe. Empty egg capsules of whelks are often found washed up on beaches. The whelk lives at depths up to 100 m. They are scavengers and have a carnivorous diet. Whelk is a true delicacy in Normandy and Britanny. The whelks are cooked and used in a starter with mayonaise. It is also a frequently used seafood in fruit des mer.