How to live for a very long time

From the BBC:

A clam dredged up off the coast of Iceland is thought to have been the longest-lived animal discovered.

Scientists said the mollusc, an ocean quahog clam, was aged between 405 and 410 years and could offer insights into the secrets of longevity.

I'm no shell-fish expert, but I would imagine that one of the secrets of this particular clam's long life would be down to so far NOT being dredged up out of its natural environment.

Just a thought.