Tube Worms

Tube worms on stone, mussel shells, whelk shell and cockle shell.

I'd noticed that some shells on the beach, particularly mussel shells, had strange white squiggly deposits on them. I assumed this was some sort of chalky material. It took me a little while to find out exactly what these were, but the Internet can be a wonderful thing and simply putting the question 'What are the white squiggly things on mussel shells?' to Google gave me the answer. They are in fact the homes of tiny tube worms, the examples in the photo, which I collected from the beach at Lundin Links today, are I think Keel Worms (Pomatoceros Species). They live permanently attached to hard structures, such as stones or shells, living inside a protective tube that they produce themselves from sand grains a chalky substance and mucus secretions. The tube narrows to a point at the tail end and has a prominent “keel” or ridge along its length. At high tide the keel worm puts out a small crown of colourful tentacles, which filter food particles from the water. When the tide goes out it withdraws the tentacles back into the tube