Green turtles life span is about 70 years. They reach sexual maturity between 18 and 30 years old, depending on their area of origin. Females have a spermatheca, so a single intercourse fertilizes their eggs for a whole season. The intercourse, taking place on the surface or in deep water, can last several hours. The eggs grow in separate oviducts, which allows their development and egg laying to take place every two weeks.