How hard do you might have to ram a fish to make it explode? Ask an orca.
Barreling into giant, heavy fish with sufficient pressure to blast them into instantaneous chum is a beforehand unknown collaborative feeding technique amongst orcas, scientifically known as Orcinus orca, often known as killer whales.
But in 2024 and 2025, divers captured underwater video of two such occasions within the Mexican Pacific Ocean and within the Gulf of California. The footage means that the brutal physique slamming could also be in service of a meal — or maybe a type of play for the orcas, researchers reported Thursday within the journal Frontiers in Ethology.
“I filmed the first event several years ago and couldn’t believe what I was witnessing,” mentioned lead research creator Kathryn Ayres, a analysis scientist for the marine conservation nonprofit Beneath the Waves and the primary to seize orcas’ high-speed ramming on video.
Ayres research sharks however observing orcas that preyed on sharks within the Gulf of California sparked her curiosity in killer whale habits. She filmed the encounter on July 29, 2024, whereas diving as an ocean safari tour information with the group Latitude Encounters, close to the coast of San José del Cabo within the Mexican state of Baja California Sur.
“The cooperative ramming behaviour itself wasn’t entirely new to me, as I had previously observed similar coordinated ramming during a hunt involving a whale shark,” she advised NCS in an e-mail.
Orcas have additionally made headlines in recent years for teaming up to ram and sink yachts in waters close to Spain and Portugal.
“What was unique in this case was the outcome,” Ayres mentioned. “Seeing the sunfish fragment into countless pieces was unlike anything I had encountered before.” Her astonishment was audible as she recorded the ramming episode. “Oh, god!” she repeatedly exclaimed.
A second video of orcas holding after which ramming a sunfish was filmed by one other tour operator within the Gulf of California in September. Both incidents demonstrated teamwork; one orca held a sharptail sunfish, scientifically named Masturus lanceolatus, by its tail, whereas one other orca swam towards the fish at excessive pace. Moments earlier than impression, the restraining orca let go, and its companion slammed into the sunfish like a freight prepare hitting a watermelon. Young orcas then wolfed up fish fragments that drifted by means of the water as their elders tore into what was left of the sunfish’s corpse.
Sharptail sunfish, or molas, are among the many heaviest fish on the planet, weighing greater than 4,000 kilos (1,800 kilograms) and measuring up to 10 toes (3 meters) lengthy.
Orcas typically coordinate their assaults in pairs or teams after they goal giant prey. However, this torpedolike physique slam and subsequent fish explosion had by no means been noticed earlier than and was “an incredible behavior to see,” mentioned Monika Wieland Shields, director of the Orca Behavior Institute. Shields was not concerned within the new analysis.
“I have never heard of anything similar to this occurring, so it is indeed a newly documented behavior as far as I know,” Shields advised NCS in an e-mail.
Though all orcas belong to a single species, their diets differ extensively relying on the place they stay. Orcas’ prey could embrace fish, seals, belugas, narwhals, baleen whales or porpoises, and might require specialised feeding techniques — together with, it appears, high-impact fragmentation.
“I think that as we continue to observe orcas more closely around the world,” Shields added, “we will continue to discover novel hunting and feeding behaviors, especially among lesser-studied populations.”
Ramming the sunfish and inflicting them to explode may assist orca calves and juveniles get extra of the stays, in accordance to the research. What’s extra, working collectively strengthens social bonds in orcas, as do shared meals. An exploded sunfish unfold out within the water in 1000’s of items is definitely simpler to share, providing one other potential rationalization for this follow.
But orcas are additionally recognized to play with newly lifeless meals. Some orcas in Puget Sound off Washington state have worn dead salmon as hats. Others drape seal intestines over their fins or take turns tossing sea lion pelts into the air, Shields mentioned.
“We’ve also seen interactions with many other objects including bull kelp, driftwood, and crab pots,” she mentioned, “In many of these cases there doesn’t seem to be a functional reason for these behaviors other than play.”
In different phrases, it’s potential that orcas body-slam sunfish purely for leisure. Ayres famous a giant wound on the fish’s physique earlier than the impression, which hinted that the orcas feasted on the creature earlier than slamming it to items.
“They had already consumed the sunfish’s internal organs, which are the most nutrient-rich parts of the prey,” Ayres advised NCS in an e-mail. “This suggests that causing the sunfish to explode may not have served an immediate feeding purpose and could have just been for fun.”
The sunfish’s flattened physique construction is uncommon in giant fish and will make them extra probably to fly aside after a high-speed orca impression in contrast with different forms of fish, Ayres added.
“Their bodies are laterally compressed,” she defined. “Once the nutrient-rich internal organs have been removed, the remaining tissues may be more accessible to rupture under high-impact ramming.”
But for now, she cautioned, that is solely a speculation.
“We haven’t seen this type of prey fragmentation described in other sunfish species,” she mentioned, “so it’s difficult to know whether it reflects something unique about the anatomy of Masturus lanceolatus, the specific behaviour of these orcas, or a combination of both.”
Mindy Weisberger is a science author and media producer whose work has appeared in Live Science, Scientific American and How It Works journal. She is the creator of “Rise of the Zombie Bugs: The Surprising Science of Parasitic Mind-Control” (Hopkins Press).
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