Whelk

Whelk is a word used for some marine gastropods. They are found in temperate and tropical waters, and are used by humans as food. The name is properly used for the family Buccinidae, sometimes called the "true whelks".
Use of the term.
Whelk is a common name, and used for gastropods of various families. 
Life of a whelk.
True whelks are carnivores and scavengers. They feed on clams, carrion, and sometimes even on detritus. Their sense of smell is very well-developed; they can sense chemical signals from their prey from a considerable distance. Many whelks can bore through the shell of bivalves. Because of this, they can cause harm in oyster farms. Whelks can even attack fish caught in a net by extending their probosces to twice the length of their own bodies.