Marine biologists have documented a remarkable hunting strategy employed by killer whales in the southern Gulf of California, in which they harvest whale sharks' organs.
Researchers in Mexico have reported four separate events between 2018 and 2024 where orcas demonstrated a collaborative approach to targeting whale sharks—the world's largest fish, which can grow up to around 60 feet long.
The study, published in Frontiers in Marine Science, described a highly coordinated hunting method where pod members work together to immobilize their massive prey.
"When hunting, all pod members work together, hitting the whale shark to turn it upside down," said Jesús Erick Higuera-Rivas, the senior author of the study.
This technique induces a state of "tonic immobility" in the whale sharks, rendering them unable to move or escape, he said.
The orcas appear to target their prey's vulnerable ventral side, focusing on the pelvic area where there is less muscle and cartilage. This strategic approach allows easier access to critical organs, particularly the liver, which is rich in lipids and nutritionally important for the predators.
One male orca, named Moctezuma, was present in three of the four documented hunting events. A female orca, potentially a pod member or relative, was also observed participating in one of the attacks.
"Orcas are renowned for their specialized hunting techniques all around the world," Anna Bunney, head of education at marine conservation charity ORCA, who was not involved in the research, told Newsweek. "Now we can add this impressive hunting technique of the world's largest fish to this repertoire."
Researchers identified individual orcas by analyzing photographs of their distinctive dorsal fins and unique features.
The discovery raises important questions about marine ecosystem dynamics and conservation. Higuera-Rivas emphasized the need for careful management of marine tourism, stating, "There must be a specific regulatory norm that guarantees that any type of non-extractive use activity is carried out in a respectful and sustainable manner."
The researchers also noted potential vulnerability in the orca pod's specialized hunting strategy. If climate change impacts the whale shark population in the Gulf of California, these orcas could face significant challenges in maintaining their unique predation method.
"It is very impressive how orcas work together strategically and intelligently to access only a very specific area of the prey," Higuera-Rivas said. "It highlights what great predators they are."
How Long Do Whale Sharks Live?
When not being hunted, whale sharks can live to 150 years, according to the World Wildlife Fund.
However, few make it this far—less than 10 percent survive to adulthood.
What Do Whale Sharks Eat?
Despite being the largest shark in the ocean, whale sharks aren't apex predators in the same way as some of their relatives. They tend to eat small fish, shrimp and plankton by sucking water in through their gills.
This is what's known as filter feeding, whereby they suck in more than 6,000 liters of water an hour through their gills to catch food. They can neither bite nor chew food like their toothier cousins.
Do Killer Whales Eat Other Sharks?
Orcas, which can reach up to around 30 feet long, are found all over the world and are extremely adaptive hunters. As you might expect, they have been documented eating sharks before.
Earlier this year, another study was published which had evidence of orcas in the Gulf of California hunting a variety of sharks, including black tips and bull sharks.
Bull sharks are large and aggressive, reaching 11 feet in length, and may pose more of a danger to the killer whales.
"The shark could be seen on surface when one orca charged the shark on its side, missing the shark only to return to try again immediately, then turning upside down and attempting to hit the shark with her tail, a hunting technique known as 'lob-tailing' or 'tail-slapping'," the authors wrote in the study.
Meanwhile, in South Africa, orcas have been documented feeding on great white sharks, one of the most renowned predators on the planet.
"Other examples of their highly specialized, cooperative and intelligent feeding strategies include pods of orca working together in coordinated attacks to create waves that can knock seals off floating ice or corralling fish and employing powerful tail-slaps to stun the fish to make them easier to catch," Bunney said.
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References
Pancaldi, F., Ayres, K. A., Gallagher, A. J., Moskito, J., Williamson, K. C., & Higuera Rivas, J. E. (2024). Killer whales (Orcinus orca) hunt, kill and consume the largest fish on Earth, the whale shark (Rhincodon typus). Frontiers in Marine Science, 11. https://doi.org/10.3389/fmars.2024.1448254
Ayres, K. A., Gallagher, A. J., & Higuera-Rivas, J. E. (2024). Orca (Orcinus orca) and shark predator-prey interactions within Cabo Pulmo National Park in the Gulf of California, Mexico. Frontiers in Marine Science, 11. https://doi.org/10.3389/fmars.2024.1407379
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