A rare encounter with a southern sleeper shark in the deep, chilly waters of Antarctica’s Southern Ocean has scientists reimagining what fauna might live in such a harsh, extreme environment.
Footage of the shark was captured in January 2025 by a baited deep-sea camera in a trench at about 490 meters beneath the sea surface off the South Shetland Islands.
“[It was] very surprising, as we didn’t think sharks were in Antarctic waters at all, let alone such a huge iconic one like the southern sleeper shark,” says Alan Jamieson, founding director of the Minderoo–University of Western Australia (UWA) Deep-Sea Research Center, which set up the camera. Jamieson adds that the shark was instantly recognizable, “as no other shark looks like these guys.”
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During the shark’s surprise appearance, which was hidden in about 400 hours of footage, marine geoscientist and center member Heather Stewart can be heard asking, “What is that that sneaks on in the background?” The researchers now think this is the most southerly report of a southern sleeper shark (Somniosus antarcticus).
These deep-sea predators, which survive on a diet of cephalopods, ray-finned fish, and even some mammals and birds, can live for 250 to 300 years, according to the center. The Associated Press reported that this individual spanned between three and four meters in length.
The shark is thought to be a female because of the animal’s lack of claspers—a pair of appendages found on male sharks—and was gracefully swimming around in an about two-degree-Celsius subsurface layer of water. This relatively less frigid corridor could allow such sharks to push farther south and into colder climes than scientists thought.
Southern sleeper sharks’ deep-sea habitat makes them tricky to study, and there have been just a few sightings of the species.
“It’s pretty rare to see these animals just because the depth they live at. These animals have sort of evolved to be quite long-lived and, like a lot of deep animals, have really slow metabolisms, so they can go a long time without eating,” said Dylan White-Kiely, a research assistant at the Minderoo-UWA Deep-Sea Research Center, in the same video.
Finding this shark so far south indicates she might not be alone in the lonely Antarctic waters. “This changes what we know about shark distribution and their ability to tolerate extreme environments,” the researchers said in a statement. “The Southern Ocean might not be as shark-free as we once thought.”
Editor’s Note (2/19/26): This article was updated after posting to include comment from Alan Jamieson and additional information.