OK, so I just tried a large whelk today (Chinese mistranslate it as "conch"). After smashing open his shell and then starting to cut him up, I immediately notice his flesh is very firm. So he was very tough after being cooked.
I was wondering, do shellfish like this breakdown and soften like land-based-meat through long cooking (or slightly long, super-hot cooking in a pressure cooker).
My understanding is no, they don't, because their muscular structure is different. The whole long-cooking thing in land animals is to breakdown collagen, which is what holds together the musce fibers. But from what I understand that's not how shellfish muscles are, right? I don't think they have collagen holding the fibers together. It's just one large dense muscle, especially for the simple animals like the bivalves and sea snails.
Am I right?