alt Hacker NewsIANAB but lobsters are worth a look. They apparently do not get slower or weaker or even lose fertility as they age. And apparently Greenland Sharks might live for 300-500 years, are immune to cancers, and their DNA can repair itself. Maybe leaving the ocean was our ancestors' mistake.
Greenland sharks are interesting because they do everything slowly, including aging. Our best guess is that pregnant Greenland sharks have at least a decade-long gestation period. Which seems like an adaptation to cold and relatively barren environments?