The shellfish gene

I've never been a big fan of shellfish ( except for potted shrimps, and where can you get them these days ? )
Treating a friend to tea on her birthday, I shuddered to hear her say she really couldn't decide whether to have the clams or the squid. Unfortunately they'd run out of clams, but offered mussels as a substitute.
She was delighted with them, but my chicken, avocado and parmesan salad looked a lot prettier.