The gray whale (Eschrichtius robustus), also known as the grey whale, is a baleen whale that migrates between feeding and breeding grounds yearly. It reaches a length of 14.9–15.2 m (49–50 ft), a weight of up to 41 to 45 tonnes (45 to 50 short tons; 40 to 44 long tons) and lives between 55 and 70 years, although one female was estimated to be 75–80 years of age. One of the longest-living Gray whales currently is a female, first sighted in 1977, and estimated to be 53–55 years old as of 2024. The common name of the whale comes from the gray patches and white mottling on its dark skin. Gray whales were once called devil fish because of their fighting behavior when hunted. The gray whale is the sole living species in the genus Eschrichtius. It is the sole living genus in the family Eschrichtiidae, however some recent studies classify it as a member of the family Balaenopteridae. This mammal is descended from filter-feeding whales that appeared during the Neogene. The gray whale is distributed in a Northeast Pacific (North American), and an endangered Northwest Pacific (Asian), population. North Atlantic populations were extirpated (perhaps by whaling) on the European coast in the 12th to 14th centuries, and on the American and African Atlantic coasts around the late 17th to early 18th centuries.