Strange: “Sharks at the Chicago Zoo give birth without any contact with males”

A shark in a Chicago zoo has made history — giving birth despite having no contact with any males.

The female epaulette shark lives in a habitat of her own at the Brookfield Zoo, located outside Chicago, where she’s lived since 2019. She hasn’t been housed with a male since her arrival, according to a press release from the zoo.

On August 23, one of the mom’s eggs hatched into a pup — only the second recorded case of an epaulette shark pup produced by asexual reproduction at an Association of Zoos and Aquariums’ accredited facility.

The first occurrence was at New England Aquarium, where Brookfield Zoo’s adult females originated.

“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,” Mike Masellis, a lead animal care specialist at Brookfield Zoo, said in a statement. “Our colleagues at New England Aquarium have been a great resource as shark pups produced parthenogenetically can be very delicate.”

On August 23, one of the mom’s eggs hatched into a pup.CZS-Brookfield Zoo

The baby shark is now two months old and about five to six inches.CZS-Brookfield Zoo

Parthenogenesis (PG) is an asexual reproduction where the female can produce an embryo without sperm to fertilize it, according to the National Institutes of Health.

According to the Britannica, PG is a natural occurrence in some invertebrates such as ants and bees, but is rare in more complex vertebrates, such as sharks.

The mama shark first came to the zoo when she was just three years old, and the zoo says the species reaches sexual maturity around seven years old.

The female shark hasn’t been housed with a male since her arrival.CZS-Brookfield Zoo

It’s only the second recorded case of an epaulette shark pup produced by asexual reproduction at an Association of Zoos and Aquariums’ accredited facility.CZS-Brookfield Zoo

She started to lay two to four typically infertile eggs each month starting in 2022. But as it turns out, one of those eggs was fertile.

The pup hatched after a five-month incubation period and has been monitored by animal care staff “behind the scenes.”

The baby shark is now two months old and about five to six inches. When fully grown, epaulette sharks can get up to two-and-a-half to three feet in length.

The pup hatched after a five-month incubation period and has been monitored by animal care staff “behind the scenes.”CZS-Brookfield Zoo

She can now be seen at the entrance of the Living Coast habitat at the zoo.

“We are looking forward to guests being able to see the pup,” Masellis said.

The mama shark first came to the zoo when she was just three years old, and the zoo says the species reaches sexual maturity around seven years old.Jim Schulz / CZS-Brookfield Zoo

Epaulette sharks are typically found in warm, shallow waters around New Guinea and Australia. They are “mostly nocturnal,” can tolerate “extremely low oxygen environments” and are known to “walk” short distances using their pectoral fins.

In order to appear larger than it is, the species has fake eyespots behind its head, which resemble shoulder decorations on uniforms — and is how the species got its name.