Little information is available regarding the mating systems of whale sharks. Like many other species of sharks, whale sharks have two reproductive extensions called claspers between two pelvic fins. These claspers assist with holding onto the female and transferring sperm successfully. In a study by Schmidt et al. (2010), 29 of 304 embryos from a harpooned female whale shark were retained for DNA analysis to determine paternity. From this 10% litter sample, Schmidt et al. concluded all 304 embroys had the same father. Embryos from this shark were also at varying developmental stages, suggesting that whale sharks may be capable of delayed fertilization.

Whale sharks are ovoviviparous, though little information is otherwise known regarding reproduction of whale sharks. Males are thought to reach sexual maturity when 30 years of age and at least 9 meters in length. Age of sexual maturity in females is unknown. In 1995, a female whale shark harpooned in Taiwan was found carrying 304 embryos. Only 15 of these were alive when their mother was recovered, and only one survived for 143 days in captivity.

Range age at sexual or reproductive maturity (male): 30 (high) years.

Key Reproductive Features: sexual ; fertilization (Internal ); ovoviviparous ; delayed fertilization

Currently very little is known about parental involvement of whale sharks. Reports of adults swimming with some younger whale sharks may suggest some measure of parental investment. It is also possible that younger whale sharks remain near adults for protection.