Often described as “living fossils,” sturgeon are one of the oldest groups of living vertebrates, with records dating back more than 150 million years. There are 25 sturgeon species worldwide, including the white sturgeon that can live over 125 years and the beluga that can weigh up to 1,500 kg. Sturgeon populations are found primarily in cold and temperate regions of the Northern Hemisphere, including North America, Europe and Asia. Among caviar-producing sturgeon, some of the most popular are found in the region bordering the Black Sea, the Sea of Azov, the Caspian Sea and the Aral Sea. The New World counts eight native species, which thrive in rivers on the east and west coasts of Canada and the United States, while additional species can be found in the rivers of Europe and central Asia, including the Danube, the Volga and the Yangtze. Despite their vast range, almost all species are threatened due to habitat destruction, overfishing, and pollution.