Anyway, the fishing nets hadn't produced much of note but when I turned over a large boulder we found this underneath.
It's the first time I've ever come across a live cowrie in all the time I've pootled in pools. I've waxed about searching for their shells before (see Trivial Pursuit) but the real deal is even better - a truly bonny beast. The tangerine stripes on the foot are magnificent as is the large orangey siphon tube. Perhaps the strangest feature of all though is linked to that orange oval on its back. This is the leading edge of the cowrie's mantle which it projects out from underneath its shell and up over the outer surface. As we watched the mollusc move, this veil was pulled up and retracted quite often. In this picture you can see that it is pulled further back.
This underside view shows the foot retracted.
There are two cowrie species in the North Sea - Trivia monacha and Trivia arctica. This one, I think, is Trivia monacha - the European Cowrie. I hesitate slightly because it is supposed to have three clear dark spots on its back. This one has only vague darkish areas but given that I found it fairly high up on the shore its unlikley to be T. arctica as this is reported as only occuring below low tide levels.
My own goal at Football Hole is to turn up a sea hare next time.