Elusive Sailback Houndshark Rediscovered in Papua New Guinea After 50 Years

The creatures are occasionally caught by local fishermen but hadn’t been scientifically recorded since the 1970s

Sarah Kuta | Daily Correspondent

August 28, 2025

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In July 1970, a fisherman caught an unfamiliar shark in Papua New Guinea’s Astrolabe Bay. The mysterious creature—a pregnant female—had large, wide eyes, a big head and a short mouth. It also had a prominent, elongated fin protruding from its back, similar in appearance to a sail on a sailboat. Researchers later identified the animal as a new genus and species: the sailback houndshark (Gogolia filewoodi).

However, after that initial sighting, scientists never saw another sailback houndshark. That is, until now—more than 50 years later, the elusive creature has turned up again.

In a new paper published this month in the Journal of Fish Biology, scientists share the first verified records of the long-lost species since it was first described in the 1970s.

Researchers rediscovered the species while collecting data to help inform Papua New Guinea’s National Plan of Action on Sharks and Rays. During that project, they learned about five female sailback houndsharks that had been caught in March 2020 by a local fisher near the mouth of the Gogol River, which drains into Astrolabe Bay.

Then, two years later, another local fisher caught a shark with a long dorsal fin near the same spot. That creature turned out to be the first male sailback houndshark ever recorded.

Though the new paper describes the first scientific record of the species in decades, local anglers do report occasionally catching sailback houndsharks while targeting other fish, mainly from March to July and from August to November.

“Fishers report that [the sailback houndshark’s] flesh is not well regarded and often given away if in surplus … and the fins are not high quality for the shark fin trade,” the researchers write in the paper.

Since it’s only ever been found in one place, scientists suspect the sailback houndshark might be a “microendemic” species with a range that’s restricted to a very small area. The same region also has other microendemic species, including bamboo sharks and epaulette sharks, reports New Scientist’s Jake Buehler. It’s also possible that, historically, the species had a larger range around Indonesia and Papua New Guinea, but “now it’s just down to this last little remnant population,” says David Ebert, a marine biologist at San José State University who was not involved with the research, to New Scientist.

Microendemic species are “highly vulnerable” to disturbances in their habitat, as lead author Jack Sagumai, a senior marine protected areas officer with the World Wildlife Fund, tells the Australian Broadcasting Corporation’s “Pacific Beat.”

“Small-scale environmental changes or development activities in the area could have significant impacts on the survival of the species,” Sagumai adds.

The sailback houndshark, for instance, might be affected by the growing demand for fish maw, the dried swim bladder of some large fish that’s considered a seafood delicacy in China. As anglers seek out more fish to harvest their bladders, they might also accidentally end up catching sailback houndsharks. The growing number of fish maw fisheries throughout Papua New Guinea has already been identified as a “major pressure” to other threatened species, including some sawfish, river sharks and winghead sharks, the researchers write.

Moving forward, the team hopes to analyze the sharks’ DNA to help inform future monitoring efforts and management actions. In the meantime, they say, the new findings highlight the value of collaborating with artisanal and subsistence fishers, especially in poorly studied parts of the world.

“Much remains unknown about its biology, ecology and population dynamics,” Sagumai tells the Australian Broadcasting Corporation. “Support is still needed to better understand the life history and ecology of this species.”

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Sarah Kuta is a writer and editor based in Longmont, Colorado. She covers history, science, travel, food and beverage, sustainability, economics and other topics.