Walruses (from Dutch walrus, probably a folk-etymological alteration - via Dutch walvis "whale" and ros "horse" - of an older Scandinavian word related to Old Norse rosmhvalr, "red? whale" or "walrus") are large semi-aquatic mammals that live in the cold Arctic seas of the Northern Hemisphere. There are 6 populations in the arctic and 2 or 3 subspecies exist: 4 in the Atlantic, Odobenus rosmarus rosmarus, 1 in the Pacific, Odobenus r. divergens and some consider the 6th in the Laptev Sea to be a third subspecies, Odobenus r. laptevi. The Pacific walrus is slightly larger, with males weighing up to 1,900 kg (4,180 lb), but Atlantic males top out at 1,600 kg (3,500 lb).