Gorillas, the largest living primates, stand up to 1.75 meters (68.8 in) tall on two feet, and have arm spans up to 2.75 meters (108 in). Adult male gorillas weigh between 135-275 kg (297-605 lb) and females, 70-140 kg (154-308 lb). In captivity, gorillas can weigh as much as 350 kg (770 lb). There are three subspecies within the genus, Gorilla gorilla, the western lowland gorilla; G. gorilla graueri, the eastern lowland gorilla; and G. gorilla beringei, the mountain gorilla. Mainly vegetarians, gorillas have special stomachs for consuming tough plant material; however, the lowland gorilla consumes vegetation and fruit.