Not sure what species of shell it is but what made the holes?
No interactions present.
Holes like this can come from boring sponges such as Cliona or can result from the activities of the small polychaete worm Polydora ciliata. There is some evidence of lateral galleries so I suspect the latter.
The more I look on the beach the more I discover I don't know and have never even heard of. Will be researching Cliona and Polydora, I'm sure they'll reapppear.
The magic of nature is all around us - we just need to learn how to see it.
Oops I didn't know it'd been commented on!
Lat/Lng: 53.8681, -3.0507
OS grid ref: SD310418