A shark locals call “kadedekedewa” has been identified as Hemiscyllium dudgeonae, a new walking-shark species found in Milne Bay, Papua New Guinea. Christine Dudgeon first spotted it in March 2025 in just a metre of water, and DNA testing later confirmed it is
On a late swim in Papua New Guinea, Christine Dudgeon didn’t expect to meet anything unusual. It was already past midnight in March 2025, and she had been in the water long enough to feel, as she put it, “a bit over it.”
She was searching for a different walking shark species, Hemiscyllium michaeli, known to live in nearby waters. Instead, she saw one swimming along the bottom—so close to shore that it was in “just a metre of water” over a meadow of seagrass in Milne Bay.
Locals have long known the strange fish, which they sometimes spot waddling across reef flats at low tide. They call it kadedekedewa. meaning “dog shark” or “lazy shark.” The animal has a rare talent: sharks in the genus Hemiscyllium. commonly known as walking sharks or epaulette sharks. use their pectoral fins like legs to move with most of their bodies out of the water. Until now, Hemiscyllium species were known only from Australia and New Guinea.
For Dudgeon, the moment came with an abrupt change in how the night behaved. When she shone her torch in front of the shark, it froze in a defensive response. The animal was nearly three-quarters of a metre long. Dudgeon then grabbed it and used a “flip and tuck” technique—researchers describe it as a jiujitsu-like move. “You sort of just flip them over and tuck the tail under your armpit and it stops them from wriggling away. ” she said.
Once the shark was secured, she handed it to her colleague, Jess Blakeway, who had been in a boat drifting nearby. Blakeway said that within seconds—“straight away,” she recalled—she could tell from the colour pattern that the shark was unlike others their team works with.
The walking sharks the team had expected to find are famously similar. The other nine species of walking shark are all closely matched in body size and shape and feed on small invertebrates that live on the seafloor. But they can be distinguished by skin patterning and colouring. The species the researchers were hoping to locate has a more leopard-like pattern. This new shark, Blakeway said, had “lots of spots and dashes” that reminded her of braille or morse code.
Over the next few days, researchers went back out to three nearby locations and caught another 11 individuals. Three were kept for further study. Nine had samples taken from them before being released.
Back in the laboratory, the decisive evidence came from DNA tests. Those tests confirmed that the new shark was genetically distinct from all other species in the Hemiscyllium genus.
The species has been formally identified as Hemiscyllium dudgeonae—named after Christine Dudgeon at the University of the Sunshine Coast in Queensland, Australia, who was part of the team that identified it.
The researchers think H. dudgeonae is found only among the coral reefs of Milne Bay in Papua New Guinea, and they believe it is probably the most endangered of all the species in the group. That conclusion lands heavily in a region where walking sharks already face severe pressures.
Papua New Guinea’s walking sharks face grave threats from habitat loss caused by coastal development, the expansion of palm oil plantations, and coral bleaching. Against that backdrop, Blakeway warned that without urgent conservation action, this species could disappear locally.
“This species adds to Papua New Guinea’s extraordinary biodiversity, yet it faces local extinction without urgent conservation action,” she said.
For a species that local communities have likely watched for generations—waddling across reef flats at low tide—being recognized as new to science is a milestone. It also adds urgency to what happens next: whether Milne Bay’s reefs can be protected before a rare walking shark is pushed out of the very places it can survive.
walking shark Hemiscyllium dudgeonae Papua New Guinea Milne Bay epaulette sharks seagrass meadow coral reefs DNA testing conservation