Females reach sexual maturity at 4.5 m ( 15 ft ) in length and 18 -- 35 years in age .
Males reach sexual maturity much earlier at 3.15 m .
Females reach sexual maturity at 4.5 m ( 15 ft ) in length and 18 -- 35 years in age , while males reach sexual maturity much earlier at 3.15 m .