A female shark in a US zoo has given birth to a pup despite having no contact with any males in the last four years, marking the second time the species is known to have undergone what’s commonly called a “virgin birth” in captivity.
“Sharks reproduce by laying eggs, but what’s most interesting is this embryo developed without the need for male fertilisation,” the Brookfield Zoo in Illinois shared on Facebook.
The process of giving birth without mating – known as parthenogenesis – has intrigued scientists in the last two decades.
A number of animals in both the wild and in captivity have been documented in recent years to have undergone parthenogenesis, including birds, non-avian reptiles, snakes, and lizards, and is relatively rare for complex vertebrates like sharks to have such virgin births.
The epaulette sharks are nocturnal creatures found in the warm and relatively shallow waters from the southern coast of New Guinea to the northern coast of Australia.
They can reach about 2.5 to 3ft in length when fully grown and can tolerate low oxygen environments, sometimes even known to “walk” short distances on land using their muscular pectoral fins.
On August 23, the Brookfield Zoo became one of only two facilities to have had successful hatching of epaulette shark pups produced by such an asexual reproduction process.
The adult female shark reached sexual maturity at 3, and was only 7 years old when she began laying eggs.
She had not been housed with a male since arriving at the Brookfield Zoo in 2019, zoo officials say.
The shark began laying two to four eggs each month of which one was fertile and a pup hatched from it following a five-month incubation period, the zoo noted.
“We are happy to report that our epaulette pup has been eating well on her diet of finely chopped capelin, minced squid tentacles, and other finely chopped seafood....We are looking forward to guests being able to see the pup,” Mike Masellis, a lead animal care specialist at Brookfield Zoo said in a statement.
