Asian elephants weigh 200–265 lb (90–120 kg) at birth. Unlike other mammals, they continue to grow well into adult life. Females cease growth at 25–30 years, males at 35–45. Fully-grown Asian elephants animals typically weigh 2-3 tonnes in females and 4-5 tonnes in males, and are 2–3 m high at the shoulder.
The elephant’s trunk is, anatomically, a fusion between its nose and upper lip. The trunk is remarkably sensitive, flexible and manoeuvrable, as well as being immensely strong. It contains no bone or cartilage, but is principally composed of muscle, in eight main sets (four on each side) comprising a total of about 150,000 separately moveable muscle units. Two nostrils run the entire length of the trunk for breathing.
Only males possess tusks, although females frequently possess tiny tusks called ‘tushes’, which can just be seen protruding from the lip, especially when the trunk is raised. A percentage (currently increasing) of males congenitally lack tusks: known as ‘mukhnas’, these animals are thought to compensate by being especially strongly-built, particularly in the upper trunk region.
The tusks are, anatomically, greatly expanded lateral incisor teeth. They are comprised almost entirely of dentine. About a third of their length is buried within a socket in the animal’s skull. The tusks are solid, except the upper part within the socket, where there is a pulp cavity. The tusks grow by addition of dentine there, pushing them out by up to 6 in (15 cm) a year. The tusks of a large bull can extend 79 in (200 cm) in total length and weigh 110 lb (50 kg) each, although such figures are rare nowadays.