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Brookfield zoo celebrates birth of shark pup through parthenogenesis – Times of India

NEW DELHI: In a fascinating event Brookfield Zoo near Chicago welcomed a shark pup born through parthenogenesis. The baby epaulette shark hatched during the summer, and its mother, who has been a resident at the zoo since 2019, has never shared a tank with a male. Parthenogenesis, a form of asexual reproduction, led to this remarkable event.
The zoo’s dedication to wildlife conservation and research is evident, as this unique birth adds to the diversity of life within the zoo.Stay tuned for updates as the shark pup continues to grow and thrive in its new home.
“Beginning in 2022, the adult female shark began laying two to four, typically infertile eggs, each month,” the zoo said in a news release. “One of those eggs was fertile, and following a five-month incubation the pup hatched and has been behind the scenes being monitored by staff.”
It’s important to note that sharks are classified as fish, not mammals, despite certain shark species giving birth to live offspring.
The shark pup, born via parthenogenesis, is currently two months old and measures approximately 6 inches. When it reaches adulthood, it has the potential to grow to a size of 2-3 feet.
“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,” the zoo’s Mike Masellis, a lead animal care specialist, said. “We are looking forward to guests being able to see the pup.”
Epaulette sharks offer a unique blend of charm and intrigue, boasting distinctive large false eye spots resembling epaulettes. These remarkable creatures are renowned for their ability to “walk” not only on the seafloor and coral but even on land.
Asexual reproduction, while observed in various species, was only recently confirmed in sharks. The Brookfield Zoo reports the second known instance of apparent asexual reproduction in an accredited zoo or aquarium, with the first case originating from the New England Aquarium in Boston, the source of the adult epaulette females at the Chicago Zoo.
Zoo staff have been receiving valuable advice from their colleagues at the New England Aquarium on caring for the young shark pup during its initial months.
This form of asexual reproduction in sharks is termed automictic parthenogenesis. Unlike conventional reproduction, where an egg is fertilized by sperm, automictic parthenogenesis involves a polar body, a byproduct of germ cells that usually get reabsorbed into the female’s body.
However, in the case of parthenogenesis, one of the polar bodies, which should have been reabsorbed, acts like sperm and fuses with the cell destined to become an egg. This results in a fertilized egg with the standard set of chromosomes but lacks the genetic diversity inherent in sexual reproduction.
Notably, around two decades ago, female bonnethead sharks demonstrated “astonishing virgin births” at the Henry Doorly Zoo in Nebraska, even without male sharks present for a prolonged period. Genetic analysis revealed the offspring had no paternal DNA. Unfortunately, the baby bonnethead shark met a tragic end, succumbing to an attack just hours after hatching.
In contrast, the epaulette shark pup has fared better and has recently made its public debut, captivating visitors in the zoo’s Living Coast exhibit.

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