An octopus has been spotted catching a ride from an unlikely marine friend: a superfast shark.
Researchers captured a video showing the orange-hued octopus clinging to the back of a large shortfin mako shark (Isurus oxyrinchus) as it swims.
This “sharktopus” was spotted in the Hauraki Gulf off the northern coast of New Zealand’s North Island during a December 2023 research trip.
“A large metallic grey dorsal fin signalled a big shark, a short-fin mako. But wait, what was that orange patch on its head? A buoy? An injury?” Rochelle Constantine, a marine biology professor at the University of Auckland who was on the research trip, wrote in a statement. “We launched the drone, put the GoPro in the water and saw something unforgettable: an octopus perched atop the shark’s head, clinging on with its tentacles.”
The researchers were bemused by this bizarre sight, as octopuses usually live on the ocean floor, while shortfin makos spend most of their time swimming near the surface.
“We really don’t know how this octopus, that lives on the seabed, came across this 3 m [meters, or 10 feet] mako shark that lives in pelagic — open ocean waters. It really is a mystery — but the ocean is filled with unexpected things,” Constantine told Live Science in an email.
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Shortfin mako sharks are the fastest shark species in the world, reaching top speeds of up to 46 mph (74 km/h). They can grow as long as 12 feet (3.7 m) and weigh as much as 1,200 pounds (545 kilograms). These sharks are known for their incredible jumping ability, being able to leap up to 20 feet (6 m) out of the water. They usually hunt near the ocean surface but have been spotted as deep as 1,640 feet (500 m). Their diet mostly consists of other fast-swimming fish such as swordfish and tuna, as well as squid and occasionally other sharks.
The researchers watched the strange “sharktopus” for 10 minutes before leaving the odd companions to continue their journey.
“The shark may not be bothered by the octopus — it certainly didn’t appear to be bothered as it swam along slowly,” Constantine said. “The octopus was keeping all of its tentacles together on the shark’s head, perhaps to avoid being seen but it could stay there while the shark was swimming slowly. I suspect the octopus would have dislodged if the shark swam faster.”
Shortfin mako sharks are listed as endangered on the IUCN Red List, largely due to their fins being highly prized in the shark fin trade. They also get caught accidentally as bycatch in tuna and swordfish fisheries, especially with longline fishing gear. Their slow rate of reproduction means that they can’t reproduce fast enough to keep up with fishing pressure, leading to population declines.
“One of the best things about being a marine scientist is that you never know what you might see next in the sea. By supporting conservation initiatives, we can help to ensure that such extraordinary moments keep happening,” Constantine said in the statement.
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