Parthenogenesis in sharks has been confirmed in the bonnethead and zebra shark. A bonnethead female produced a pup by parthenogenesis. Like other hammerheads, the scalloped bonnethead is viviparous, with presumably two pups per litter. Typically, bonnethead sharks are about long, with a maximum size of about . On January 19, 2009, 15 bonnethead sharks died due to a maintenance error.