Live-bearing sharksAlmost 70% of the sharks living today have developed a method to care for their brood inside the female's body. In many aspects it resembles the reproductive method of mammals. The eggs are fertilized in the upper part of the fallopian tube and are encased in only a very thin membrane. The females then retain the developing eggs in the last extended section of the fallopian tube which is thus termed the womb or uterus. Protected by the mother's body, the pups develop and are born as self-sufficient sharks following a gestation period of 6 to 22 months. The size of the pups at birth is usually between 45 and 60 cm.