What animal has the longest lifespan?

The bowhead is a mysticete whale, a suborder of cetaceans characterized by rows of baleen plates for feeding on plankton, a symmetrical skull and paired blowholes. The species is recognized by its large skull (it represents about a third of its body length), and the prominent upturned lower jaw. Adult bowheads have an average length of 15 to 18 meters, with a particulary large specimen reported at 19.8 meters and over 100,000 kg in weight. The species is essentially found in the arctic region, in association with ice floes. Because these whales do not have teeth - often used to estimate age in other mammals - it can be difficult to determine their age. However, data has shown that bowhead whales may be among the longest-lived animals on earth. Based on the recovery of stone harpoon tips in their blubber, and from analysis of eye tissue, scientists believe that the life-span of bowhead whales can be over 100 years. One individual in a study was believed to be more than 200 years old.