This common whelk shell plummeted from the sky as we sat by the harbour at Scarborough at the weekend, bouncing off Barbara’s leg then smashing into several pieces as it hit the concrete next to a stack of lobster pots. We didn’t see who dropped it but I suspect the herring gulls which were arguing amongst each other.
On the top left you can see the whelk’s siphonal canal. When it is hunting, the whelk’s siphon tube protrudes from this groove and swings from side to side as locates its prey using scent receptors.
Whelks produce a ‘purpurin’, a purple dye which is thought to immobilise their prey.
Keel worm cases encrust the exterior and some of the smooth interior of the shell.