Shark reproduction varies from once each year to at irregular intervals several years apart. Mating also varies among species, from those that mate year-round to those that prefer certain seasons and regions, often affected by migration.
Sharks usually reach sexual maturity at 12 to 15 years of age. Some species, like the great white, bear just one or two pups per litter, while others, like the whale shark, may have more than 100. Roughly 70 percent of sharks are live-bearing, while the others lay eggs that hatch if they survive predation. Gestation periods normally range from 6 to 22 months.