The embryos feed on egg yolk and there is no placental connection to the mother. The number of litters and the size of the newborns are unknown, but the gestation period is thought to be between 1 and 3.5 years.
Males probably reach sexual maturity at 4-5 meters in length, corresponding to an age of 12-16 years. Females mature at 8.1-9.8 meters.
Basking sharks have an average life span of about 50 years.
