1965, he gave a portion of this culture to Dorothy Spangenberg, and she in turn gave Cabrillo Marine Aquarium some in 1994. They were still large medusae in the tank, but I believe they were no longer tracked once she left. Mike Schaadt at Cabrillo Marine Aquarium told me recently that he had one that he knew was at least 6. As for a single polyp, I ran an experiment a few years back to see, and unfortunately it was destroyed before the answer became known. IN that time, each of 3 stobilated twice and produced approximately 60 buds.
Details are in forthcoming in print.
I have heard stories of monstrously old anemones, but I know no details. Else, Oregon Coast Aquarium has had some of theirs in their cylinder tank since they opened, making them at least 8-9 yrs. It has been suggested that some tropical anemones live to 100 yrs or so and their cold water conterparts even longer. If you count corals colonies as individual animals, then probably 1000's of years. Of course one would have to define if a coral colony is an individual cnidarian or a mass of individual polyps.