Brookfield Zoo in Illinois has welcomed a new addition to its marine family — a baby epaulette shark born through parthenogenesis. In other words, the mother shark had a “virgin” birth. According to NPR, the unique birth occurred this summer and has captivated both zookeepers and visitors alike.
The Mother Never Shared A Tank With A Male
Sharks are fish, so most of them lay eggs to create offspring, but usually, they still need a daddy shark to fertilize the eggs. The mother of the newborn epaulette shark had resided at the zoo since 2019 and had never shared a tank with a male during her stay, technically making this epaulette pup virgin birthed.
The process that led to this rare occurrence of a shark virgin birth began in 2022 when the adult female shark started laying two to four eggs each month. Typically, most of these eggs were infertile. However, one of them turned out to be fertile, leading to the development of the baby shark.
The Shark Had A Parthenogenesis Birth
The shark’s virgin birth is called parthenogenesis, a type of asexual reproduction that is exceptionally rare in the animal kingdom and even more so in sharks. It involves the development of an embryo without the need for fertilization by a male. While some shark species do give birth to live young, this unique event showcases the diversity of reproductive methods within the shark world.
Baby Shark Is Healthy
After the Brookfield Zookeepers noticed their epaulette shark had created a virgin birth egg, they attentively watched the fertilized egg sit through a five-month incubation period. After that, a healthy pup hatched and has been under the close watch of the zoo’s dedicated staff. The baby epaulette shark is currently two months old and measures around six inches in length.
These sharks have the potential to grow into adults that are two to three feet long when fully mature. According to Mike Masellis, a lead animal care specialist at the Brookfield Zoo, the pup is in good health and has been thriving on a diet of finely chopped capelin, minced squid tentacles, and other finely chopped seafood. Zoo staff were eager to introduce the pup to visitors anxious to see the shark born out of virgin birth.
This Is Only The Second Recording Ever Of A Virgin Shark Birth
This remarkable event at Brookfield Zoo represents only the second known case of epaulette sharks giving apparent virgin births. The first documented instance of parthenogenesis in this species occurred at the New England Aquarium in Boston. Luckily for the Brookfield Zoo, the New England Aquarium offered valuable insights to help the staff in Illinois care for their young pup during the crucial initial months.
Parthenogenesis More Commonly Occurs In Vertebrates
Parthenogenesis, while less common in vertebrates, has been observed in various animal groups, including insects, reptiles, birds, and fish. Sharks, however, were not confirmed to undergo parthenogenesis until relatively recently. The first discovery of sharks experiencing virgin births occurred with a female hammerhead at the Henry Doorly Zoo in Nebraska about 22 years ago.
While the evolvement of sharks giving virgin births eliminates the need for a male’s contribution, it also reduces the genetic diversity that sexual reproduction would provide. Remarkably, the epaulette baby born through this process has survived and recently made its debut in the Brookfield Zoo’s Living Coast exhibit.