basking sharks are ovoviviparous, meaning that the young embryos develop in a yolk sac inside of the female, but they aren’t attached to a placental connection. it is believed that the females can delay gestation so that they may remain pregnant from 1 to 3 years. mating occurs in the early summer and the females often move to very shallow water when ready for the young to be born. she may have up to 6 pups that are up to 6 feet long. the age of maturity is from 6 to 13 years. basking sharks start mating when they are around 15 to 20 feet long.