In the second known case of shark parthenogenesis(単為生殖), a female Atlantic blacktip shark in the Virginia Aquarium & Marine Science Center became pregnant while in captivity away from males of her species. In May 2007, the 5-foot (1.5-meter) shark died and underwent a necropsy(検死). It was then that aquarium officials discovered that she was carrying a nearly full-term(臨月の)pup(子). DNA testing showed that the pup had no father. This second case of asexual(無性の)reproduction in sharks has convinced scientists that the first case was not merely a fluke(まぐれあたり、幸運)of nature, and they are now trying to determine how common this form of reproduction is in wild shark populations.