Whelk is a common name that is applied to various kinds of sea snail. Although a number of whelks are relatively large and are in the family Buccinidae (the true whelks), the word whelk is also applied to some other marine gastropod species within several families of sea snails that are not very closely related. Many have historically been used, or are still used, by humans and other animals for food. (In an average whelk (100g), there are 137 calories, 24g of protein, 0.34g of fat, and 8g of carbohydrates.) Dog whelks were used in antiquity to make a rich red dye that improves in color as it ages.