This epaulette shark has an exciting hatch-day story. Photo: Brookfield Zoo//Facebook
Sharks are pretty wild creatures, aren’t they? Skin like sandpaper. The ability to sense electromagnetic fields. Around for 455 million years. All sorts of weird little quirks have evolved over those millions of years, and apparently some of them have an even wilder ability: virgin birth.
On August 23, an epaulette shark pup was born at the the Brookfield Zoo in Illinois. After a five-month incubation period, the pup emerged from its leathery little egg. It was just a tiny thing, only a few inches in length, and the people in charge of caring for the animals at the zoo were flummoxed. Flummoxed because the pup’s mother hadn’t been in contact with a male since 2019, when she was moved to Brookfield from an aquarium in New England. Strangely, that New England aquarium reported the first-ever epaulette virgin shark birth a few years prior. Last year, the shark reached her sexual maturity — seven years old, if you’re interested — and she began to lay a few eggs every month. Those eggs, as is almost always the case, amounted to nothing, because there weren’t any males around to complete the process.
“This epaulette shark has an exciting hatch-day story,” Brookfield Zoo staff wrote in a Facebook post on November 9. “What’s most interesting is this embryo developed without the need for male fertilization. This process, known as parthenogenesis, is relatively rare for complex vertebrates like sharks.”
Parthenogenesis, which means “virgin creation” in Greek, is fairly uncommon. It has, however, been seen a few times in the past. Several birds here and there, some lizards and snakes, and a crocodile back in June, but it doesn’t happen often, even in species that can technically do it. Mammals can’t do it, obviously, but species that are able to experience parthenogenesis lay eggs that have all the genetic information they need to become an animal. Mammals require the genes that come in sperm to make that baby.
The zoo didn’t announce the pup’s birth until November 9 because it was keeping a close eye on the newborn for a reason. “Shark pups produced parthenogenetically can be very delicate,” Mike Masellis, a lead animal care specialist at Brookfield Zoo, said in a statement.
Epaulette sharks are cute little creatures, not at all dangerous to humans. Epaulette sharks are about nine million years old. That’s pretty old, right? But in shark species, it’s nothing. Epaulettes, as you can see, aren’t exactly a shark you need to be worried about and they’re certainly one of the most interesting ones. Case in point: they can walk on land.
According to the Aquarium of the Pacific, while they do indeed have the capability to swim, most of their movement comes from “walking.” They move around relatively smoothly on their little fins, navigating over rocks and lumps of coral while searching for bottom-dwelling invertebrates, which make up the brunt of their food.
They’re most often found in warm, shallow rock pools that don’t have too much oxygen. To survive, they’ve developed the extraordinary talent of increasing the blood supply to their brain, but shutting down the non-essential brain functions.
According to Masellis, enough time has passed to ensure that the miracle shark is likely going to be just fine. “We are happy to report that our epaulette pup has been eating well on her diet of finely chopped capelin [fish], minced squid tentacles and other finely chopped seafood,” he said. “We are looking forward to guests being able to see the pup.”
