A shark with no dorsal fin surprisingly appeared on the screen as crew from Paul Allen's research vessel Petrel explored ship wreckage from World War II in Philippine waters using a remotely operated submersible.
"Sixgills don't have dorsal fins," a researcher can be heard saying in the video.
"Can you zoom in, Rick?"
As he did, the shark turned toward the camera and revealed what they all thought. It was a rarely seen sixgill shark.
"This is remarkable footage of the bluntnose sixgill shark, a rare and deep-dwelling species of shark," Gonzalo Araujo, Executive Director of the Large Marine Vertebrates Research Institute Philippines (LAMAVE), said in a Paul G. Allen blog post.
"This, to our knowledge, is the first live encounter with the species in the Philippines, with only a few records known from fisheries. It highlights the rich marine biodiversity of the country and the need to sustainably manage it."
The researchers collected the footage of the shark near wreckage at 850 feet in Ormoc Bay earlier this month, according to CNET.
The video was posted Monday on YouTube for the first time by Seattle-based Vulcan, "the engine behind philanthropist and Microsoft co-founder Paul G. Allen's network of organizations and initiatives."
Reaching up to 15 feet long, the bluntnose sixgill shark (Hexanchus griseus) is one of the largest sharks in the world, but uncommon in the area. Reflecting primitive characteristics from the Triassic period, the sixgill shark has more extinct relatives than alive.
While the Philippines has nearly 200 kinds of sharks and rays, local researchers say this species of shark has never been documented alive in the country's waters until this expedition.
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