In dives off Mexico’s Revillagigedo archipelago, scientists watched Galapagos sharks rub their snouts and gill regions against manta rays—behavior consistent with parasite removal rather than aggression. The unusual encounters, documented between December 2024
The first thing the researchers noticed wasn’t a hunt. It was friction—Galapagos sharks sliding their snouts and gill regions against the top and bottom surfaces of manta rays during dives off Mexico’s Revillagigedo archipelago.
They documented the behavior at three different dive sites between December 2024 and January 2026. In each case. the rubbing looked deliberate: juvenile sharks worked the mantas as if they’d found a surface that could reach exactly where they needed it. while the mantas themselves appeared to tolerate the contact with only mild shuffling.
Adult sharks behaved differently. When they approached the same mantas, they went into flight mode—rolling backward and trying to escape a potential bite. The researchers say that contrast matters, because it suggests the interaction wasn’t an attack. The sharks specifically targeted places known for sea lice. focusing their rubbing on their snout and gill regions—hotspots where parasites can cling. In other words, the manta rays weren’t being treated as prey. They were being treated as something closer to a giant scratching post.
This wasn’t the first time sharks were seen using abrasive surfaces to deal with parasites. Galapagos sharks have previously been spotted scratching their snouts and gills on whale sharks. The mechanism seems to be the same: shark skin—and manta skin—is rough. Shark skin is made up of dermal denticles shaped like teeth, sharp and rugged. Jane Vinesky. a marine ecologist and lead author of one of the studies. explains why that matters: “That’s why they’re nice places to scratch.”.
Two separate groups of researchers documented a total of eight shark-manta encounters, publishing their observations in Marine Biodiversity and Environmental Biology of Fishes.
Mauricio Hoyos, a co-author of the latter study and director of the marine conservation nonprofit Pelagios Kakunjá, connects the dots in a simple way. “The sharks know that the surface of the manta is like sandpaper, so it’s a good surface to remove those parasites.”
The find also lands in the middle of a larger question about how sharks cope when they’re burdened by parasites. When sharks have a parasite problem. they often move toward cleaning stations—nature’s “spa. ” where small cleaner fish peck parasites off their clients. But sometimes those stations get crowded. Hoyos points to that competition as a possible driver behind alternative strategies.
Gregory Skomal. a marine biologist who heads the Massachusetts Shark Research Program and was not involved in either study. called the newly observed behavior “unique and exciting.” He has seen smaller fish use sharks as exfoliators to scrape off parasites. and he sees the shark-manta interaction as part of a wider pattern of animals improvising.
What still isn’t clear is how the behavior starts. Hoyos wonders whether sharks might have learned from smaller fish that scratch their own itches on sharks. Skomal offers another possibility: individuals may try something one day, discover it works, and keep doing it. “In the world of sharks,” Skomal says, “a lot of what they do involves trial and error.”.
When you watch a Galapagos shark slide its snout along a manta’s body. the moment can look oddly personal—like it’s solving a problem it can’t reach on its own. In the Revillagigedo dives. the evidence points in the same direction every time: rubbing that matches the body locations where sea lice tend to gather. and a behavior pattern detailed over two years of observations. For marine life that lives at speed and depth. it’s a reminder that even “unreachable itches” don’t have to go unanswered.
Galapagos sharks manta rays Revillagigedo archipelago sea lice parasite removal Marine Biodiversity Environmental Biology of Fishes marine conservation cleaner fish
So basically sharks are using sea cats? Thought it was gonna be like jaws stuff.
I don’t know why people are shocked. If your face is covered in parasites you’d rub on literally anything. Sharks are just doing self-care apparently.
Wait so adult sharks roll backward like it’s a bite?? That seems like aggression to me, like they’re scared of the manta. Also how do they even know it’s for sea lice and not just knocking the manta around??
Manta rays just out there letting sharks rub them? I’ve always hated sea lice talk like it’s gross, but this is kinda wild. Revillagigedo sounds made up, like where is that, and are the researchers sure the sharks weren’t trying to eat the mantas from the top/bottom or whatever. Either way I’m not getting in that water.