A new species of walking shark has been described from the shallow waters of Milne Bay Province in southeastern Papua New Guinea, bringing the total number of known walking shark species to 10. The species, named Hemiscyllium dudgeonae (Dudgeon’s walking shark, or Dudgeon’s epaulette shark), was discovered during a night dive in March 2025 by Jessica-Ann (Jess) Blakeway, a PhD student at the University of the Sunshine Coast in Queensland, Australia.
Walking sharks are members of the genus Hemiscyllium, a group of small, bottom-dwelling sharks that use their muscular pectoral and pelvic fins as four limbs to crawl across the seafloor. Unlike most sharks, they can survive out of water for roughly two hours by slowing their heart and breathing, allowing them to hunt in tidal pools that other predators cannot access. The discovery was published June 15 in the Journal of the Ocean Science Foundation.
Blakeway immediately recognized the specimen as unusual when it was brought aboard under boat lights. Its color pattern, brown freckling interspersed with white spots and dashes on the head and body, and a prominent eye-like spot behind the pectoral fins, differed from all nine previously described species. The holotype, a 673-millimeter male collected near Yabwaia Island at a depth of 8 meters, is now deposited at the Western Australian Museum.
The species is named after Christine L. Dudgeon, a senior research fellow at the University of the Sunshine Coast and an elasmobranch geneticist who has studied the Hemiscyllium genus for more than 20 years. Dudgeon was the first to collect the specimen.
A Radiation Across the Indo-Australian Archipelago
The genus Hemiscyllium split from its sister genus Chiloscyllium approximately 44 million years ago. During the Miocene and Pliocene epochs, tectonic changes and sea-level fluctuations drove a rapid radiation across the islands of eastern Indonesia, Australia, and New Guinea. Each species now occupies a remarkably small geographic range, often just a few hundred square kilometers of shallow coral reef, seagrass bed, or mangrove habitat.
The new species is the first walking shark described since Hemiscyllium halmahera was discovered in 2013. The 10 species now span a timeline from 1788, when the well-known epaulette shark H. ocellatum was first described, to the present.
Blakeway and her colleagues conducted 70 dedicated surveys at 35 sites across 15 locations, using diving, snorkeling, and reef walking, collecting all specimens by hand. The paper also revised the known distributions of two other PNG species, H. michaeli and H. hallstromi, revealing that their ranges overlap geographically despite not co-occurring at the same sites, overturning the previous assumption that rivers or deep water kept them apart.
The Most Endangered Walking Shark?
Five of the 10 walking shark species are already listed as threatened with extinction under the IUCN Red List’s Criterion B, which applies to species with restricted geographic ranges, a category that covers only about 3 percent of all shark species globally. H. dudgeonae has not yet been assessed, but the research team aims to evaluate it in an October 2026 expedition.
The species’ range appears to be limited to Milne Bay Province, between the Amphlett Islands and the Trobriand Islands. If confirmed, this would make it the most range-restricted of all walking sharks and a strong candidate for a threatened listing.
Threats include coastal development, expanding palm oil plantations, coral bleaching driven by climate change, and incidental catch in small-scale fisheries. Locally, the shark is known by the name kadedekedewa, meaning “dog shark” or “lazy shark” in reference to its slow, four-finned gait. Researchers report that local communities in Milne Bay are “excited and proud” of their endemic biodiversity, and Dudgeon expressed hope that the discovery would “raise the profile of the species and result in protections that support habitats and broader biodiversity.”
“We hope that it will be cherished in Papua New Guinea and beyond,” said lead author Jessica-Ann Blakeway.
The researchers caution that more than half of walking shark species are threatened. As Blakeway noted, walking sharks are hardy animals, if they are struggling, other marine species in the same ecosystems are likely struggling as well.
Source
Blakeway, J.-A., Townsend, K., Erdmann, M., Allen, G., Teliwa, M., Waranaka, J.-A., Brooks, W. & Dudgeon, C.L. “A review of walking shark (Hemiscylliidae: Hemiscyllium) distributions in Papua New Guinea and description of a new species.” Journal of the Ocean Science Foundation 46, 71–110 (2026). DOI: 10.5281/zenodo.20575429.