Scientists have discovered that the Greenland shark—which you can find swimming around sub-arctic waters—is the longest-living vertebrate in the world.
These sharks can grow to weigh to more than 2,000 pounds and prefer water temperatures between 30 and 50 degrees Fahrenheit.
Researchers have found, thanks to carbon dating the sharks' eye lenses, that the average lifespan for this species is 272 years. They predict that the largest of the species, which stretched over 16 feet long, could have been anywhere from 272 to 512 years old.
This is only the best estimate scientists have in terms of accurately dating the species. Since fish are generally aged based on calcified body tissue (the same kind of process that's used to date a tree via growth rings), studying age based on eye lenses is relatively new territory.