In a recently-viewed episode of Good Eats, Alton Brown mentioned that properly stored in a refrigerator with a damp towel over the container, oysters could live as long as a week. Then he showed how to open and prepare them.
So, when exactly is an oyster no longer alive? Is it when the shell is forcibly opened, when the oyster knife goes under it to separate it from the bottom shell, or... or... or.... I can't say it.