Have you ever wondered which animals live the longest? Human life expectancy varies significantly across the globe from just 45 years in Swaziland to 82 years in Switzerland
. How does that compare to the animal kingdom's old-timers? According to a list compiled by Discovery News, the Ocean Quahog, a bivalve mollusc living on the North Atlantic seabed, is the world's longest-living animal. The top three is completed by the Bowhead Whale and the Rougheye Rockfish.