Whelk

whelk is a large marine mollusc, inhabiting a single shell. Whelks are widely distributed, but are commercially exploited in only some regions. They are carnivorous, scavenging among carrion or preying on other molluscs, using their extensible proboscis, tipped with a radula, to reach into and extract nourishment from their victims. In certain climatic conditions they can absorb toxin from their prey, and are capable of retaining this for several months; so their harvesting is best left to professional and knowledgeable gatherers.