THE NOTCH at the front of the shell is for a siphon tube. The whelk uses the tube
for searching out carrion - dead fish and crabs and suchlike - underwater.
Common Whelk, Buccinum undatum
Keelworms, Pomatoceros lamarcki, have constructed their keeled tubes inside the discarded
whelk shell. They’re members of the tubeworm family Serpulidae and they feed by spreading
a crown of brightly coloured tentacles from the mouth of the tube.