Newly discovered spookfish shines light on mysterious ghost sharks
Found off New Zealand, the species adds crucial knowledge about this little-known and odd-looking group of deep-sea fish
In a discovery fit for Halloween, scientists have announced a new species of ghost shark in deep waters off New Zealand.
Ghost sharks, a group of primitive fish that inhabit oceans worldwide, have many names, including ratfish, elephant fish, and rabbit fish; the newfound animal is called the Australasian narrow-nosed spookfish.
With their large, round eyes; pointy noses; and wing-like fins, ghost sharks "are rather cute,” but little understood due to their remote habitat, says David Ebert, director at the Pacific Shark Research Center at California’s San Jose State University and co-author on a recent study about the newfound fish.
Yet thanks to new technology, such as remotely operated vehicles, 27 of the 59 known ghost shark species have been discovered in the past 20 years, three of them just in 2024—including the spookfish.
Fisheries scientist and study leader Brit Finucci had a hunch that ghost sharks around New Zealand are unique species. (See a ghost shark filmed in the deep sea for the first time.)
“[Our team] decided to investigate this suspicion, and after a few years of collecting samples at sea, measuring museum specimens, and completing genetic analyses, we had our answer,” Finucci, of New Zealand’s National Institute of Water and Atmospheric Research, told National Geographic via email.
Finnuci, whose research appeared recently in the journal Environmental Biology of Fishes, named Harriotta avia after her grandmother; avia means grandmother in Latin.
Ghost sharks “are also rather ancient relatives—the grandmas and grandpas—of fish, and I thought the name was well suited,” Finucci said in a statement.
Neither ghosts nor sharks
Ghost sharks originated during the Carboniferous period, around 375 million years ago—during the time sharks also evolved, says study co-author Dominique Didier, an ichthyologist at Millersville University in Pennsylvania.
“The amazing thing is that, if we examine fossils from that time period, they look very similar to the living [ghost sharks] we see today,” she said by email. “Hence, these fish are sometimes considered ‘living fossils.’”
Despite their name, ghost sharks are distant relatives of sharks. They have shark-like features, such as smooth skin and a cartilaginous skeleton. Male claspers also transfer sperm to females, and females deposit egg cases.
Because of their unusual appearance, ghost sharks are also called chimaeras—a nod to the Greek mythological monster chimaera, who has a lion’s head, goat’s body, and snake’s tail.
According to Didier, most of the information we know about these creatures is based on ROV footage and observations of the three species that survive in captivity: the spotted ratfish, the Australian ghost shark, and the Cape elephant fish. (Learn about an odd ghost shark with a sex organ on its head.)
“Because they live so deep and it’s very hard to observe living specimens in the wild, we know very little about social behavior and habits,” she adds. “It seems that adults and juveniles live separately, and males and females also may live in separate groups."
Ghost sharks are likely to be key players in seafloor food webs. As predators, they use beak-like teeth to hunt crabs, mollusks, octopuses, and other bottom-dwelling species, Finucci says. They’re also prey for larger animals, like leopard seals.
Ghost sharks aren’t easy meals, though—they yield a large, jagged spine on their first dorsal fin to defend themselves, she says.
“There's several documented examples of predators being impaled by chimaera spines, including people!”
Gareth Fraser, a biology professor at the University of Florida, says by email that the discovery of the new spookfish is a “wonderful and thorough description.” It also contributes further evidence that "the seas around Australia and New Zealand are prime chimaera habitat.”
"Like all studies of animals in the wild, especially those found in the deep oceans, this type of work is difficult, and such a well-done study is rare,” adds Fraser, who was not involved in the research.
Shrouded in mystery
Back in 1983, Didier became one of the few people to study ghost sharks. “I was attracted to the idea that almost nothing was known about these fish,” she says.
In the decades since, Didier, along with Ebert, Finucci, and more have expanded the general knowledge about ghost sharks, as well as observed further scientists and the public show interest in the fish. (Learn about more ghostly species.)
“Which is really exciting for me, to see them go from near obscurity to international recognition,” Didier says.
But there is still plenty to discover: How big can they get? How many other species exist? How do they find their mates?
“I would love to know where they lay their eggs and where the newly hatched young aggregate,” says Didier, who adds finding baby ghost sharks is extremely rare.
Finucci wants to know how old these fish can get; Greenland sharks, which can live at least 300 years, are the longest-lived vertebrates on Earth.
“We have no idea how to reliably age them,” she says. “Many deep-sea species are slow-growing and long-lived, so it's plausible that chimaeras may also exhibit similar characteristics.”
As for Fraser, he wonders: “What other unique and unseen sea creatures are lurking in the deep?”
