Great white sharks reproduce via internal fertilization, and fertilized eggs are retained in the body until a short while after hatching in a 12-month gestation, after which the young are born live. Prior to birth, the young may eat unfertilized eggs and smaller unborn sharks in the womb. Newborn great white sharks receive no parental care, and swim away immediately after birth.
Sharks breed between the ages of 9 and 23 and have a lifespan between 30 and 40 years. The largest sharks can reach 23 feet in length and well over 3 tons in weight. The females tend to be substantially larger than the males. When they are young, their diets include smaller animals such as squid, stingrays and smaller sharks. Older sharks prefer mammalian prey, including seals, sea lions, dolphins and whale carcasses. Their approach to hunting varies, but the most common strategy is to attack unseen from below, striking with such force that sometimes both shark and prey burst free of the water's surface. A single massive bite severs appendages and causes severe blood loss, and the shark feeds after the prey dies from these injuries. Their upper and lower jaws work differently, with the lower jaw holding the prey while the upper cuts and tears.