Answer:
The viviparous sharks who carry the eggs until the pups are born, have different gestation periods.
The dogfish shark is known to keep their eggs for 18 to 24 months.
The bull shark gestation is about one year.
The hammerhead shark gestation period is from 7 to 12 months.
Other species that are ovoviviparous carry the eggs until the pups born alive and fully developed. They also have long gestation periods.
The tiger shark gestation is about 14 to 16 months.
The great white shark gestation is about 11 months.
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