New species of walking shark discovered off the coast of Papua New Guinea

A walking shark moves the way its name suggests. In water shallow enough to wade in, it pushes itself along the bottom, using all four fins like legs. Each kind does that in one small stretch of coast and nowhere else.

Off Papua New Guinea, divers have now found a tenth kind, freckled brown, with white spots and dashes along its sides. Its known range is the smallest of any walking shark, about 2,700 square miles (7,000 sq km) of shallow water, a square roughly 50 miles on a side.

That’s the area the team could confirm, and they think the animal reaches beyond it. They also expect it to be listed as endangered once anyone assesses it. This species got its name and its first warning in the same paper.

White dashes set the new shark apart

The team went to eastern Papua New Guinea to count walking sharks they knew about. Between November 2023 and March 2025 they ran 70 surveys, averaging 84 minutes each, over coral reefs, seagrass beds and mangroves. They caught the animals by hand, diving, snorkeling and walking the reef flats.

Christine Dudgeon, a shark geneticist at the University of the Sunshine Coast, picked one up in the Amphlett Islands and brought it back to the boat. PhD student Jess Blakeway saw it in the lights.

“The first thing that stood out was the white dashes along its brown body,” Blakeway said. “These dashes were quite different to the leopard-like spots we were expecting.”

Leopard spots belong to Hemiscyllium michaeli, the walking shark already known from that coast. Over the next two nights the team found 11 more sharks with the dashes. Each went into a tub of seawater to be measured and sampled, and all but three went back onto the reef.

Dudgeon caught the shark named after her

Formally the animal is Hemiscyllium dudgeonae, described by Gerald Allen of the Western Australian Museum, Mark Erdmann of Re:wild and Blakeway.

Walking sharks are also called epaulette sharks, so the common name is Dudgeon’s epaulette shark. She has spent two decades studying them.

“New shark species don’t come along that often, and it’s most definitely the first one named after me,” Dudgeon said.

People around the Amphlett Islands call it kadedekedewa, which translates loosely as dog shark or lazy shark, after its slow four-limbed walk. In the Trobriand Islands to the north it is botabota.

One gene could not tell them apart

Color is enough to sort walking sharks in the water, but not enough to name a new species. The team’s two DNA methods didn’t agree with each other.

They started with a short stretch of DNA that sharks inherit only from their mothers, which has distinguished walking shark species before. It failed here. All 12 of the new animals came back with identical sequences, and those sequences put them inside H. michaeli rather than beside it.

Then the team scanned thousands of markers spread across the whole genome, and the new shark separated cleanly from H. michaeli.

Species that split recently can still carry pieces of DNA that look the same in both species, and that, the researchers think, is what happened here. Biologists met the same problem in 2018 with two devil rays the standard DNA markers couldn’t tell apart, and genome-wide data separated them two years later.

A 1970 juvenile was misidentified

Confirmed sightings come from five places in Milne Bay Province, three sites in the Amphlett Islands and two in the Trobriands to the north.

The known depth range runs from about 2 to 40 feet (0.5 to 12 m). These are sharks a person can pick up in both hands, living over seagrass and scattered coral in the shallows.

One of those Trobriand records has been in a jar since 1970. A juvenile 10 inches long (26 cm) was collected at Munuwata that June and sent to the National Museum of Natural History in Washington. In 2010 it was filed as a young H. michaeli.

Blakeway’s team looked again and found the new species instead. So the shark lives at least 50 miles (80 km) north of the Amphletts. A shark can spend decades on a museum shelf before anyone works out what it is.

Fishermen at Tuma Island, in the northwest of the same group, have caught and photographed two more adults.

Some reefs may have lost their sharks

The team also searched south of the Amphletts, across six locations in the D’Entrecasteaux Islands and nearby Uama Island, and saw no walking sharks. Community members had named some of those spots as easy places to find them. The authors wrote that the species may already be gone from some of them.

In Papua New Guinea, coastal building, palm-oil plantations and coral bleaching degraded an estimated 20% of walking shark habitat in the 10 years to 2020. Fishing adds to that, most of it for food.

Farther along the coast in Oro Province, the small round bones of a walking shark’s spine are strung into jewelry and sold to tourists.

Those bones come from a different species in the same group. Around the Amphletts and the Trobriands, cruise-ship visitors and residents have described heavy fishing for food, though those accounts are secondhand.

Researchers expect an endangered listing

Five of the nine walking sharks named before this one are already threatened with extinction on the IUCN Red List. All five qualified under a rule about small geographic range, which applies to only about 3% of sharks.

Papua New Guinea protects no walking shark species by name. The authors want all ten added to the country’s Fauna (Protection and Control) Act.

The team still doesn’t know where this shark’s range stops. The authors expect it turns up in the D’Entrecasteaux Islands too, and maybe as far east as Woodlark Island, but the surveys that would settle it haven’t been done. They also can’t say whether the sharks south of the Amphletts were missed or are gone.

Blakeway said the team plans to go back in October and gather more data for the Red List assessment. That trip is where the answer would come from.

The full study was published in the Journal of the Ocean Science Foundation.

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