Anyone kept a flame scallop for a while?

I've read they just don't have a naturally long life span in the wild, a couple years at best. Mine is good sized, so it's no baby. It's doing quite well, I was very picky when shopping for one. I've had it for about 4 months. I'm just curious what to expect for a life span in captivity. I'd like to hear some first hand experience, forum searches seem to have everyone quoting the same source...