A newly described hunting behavior turns one of the ocean’s heaviest bony fish into confetti. Researchers think it may help calves eat — or it may simply be a game.
Orcas have never needed help with their reputation. They take down great white sharks, drown whale calves larger than themselves, and coordinate hunts with a tactical sophistication that marine biologists still struggle to fully catalog. Yet even against that backdrop, a pod in the Gulf of California has managed to add something genuinely new to the repertoire: a two-orca maneuver in which one animal holds a sunfish carcass steady while another slams into it at speed, shattering the fish into thousands of drifting fragments.
The behavior, documented in two separate encounters roughly fourteen months apart and described in Frontiers in Ethology, has never before been recorded as a predation strategy in orcas. “We document how one orca holds the sunfish and lets go just before another orca hits it at high speed, causing the tissue to break apart into thousands of pieces,” said Dr. Kathryn Ayres, the study’s first author and a scientist at the ocean-health nonprofit Beneath The Waves.
Why would a predator go to such lengths? Ayres and her colleagues offer two answers that are not mutually exclusive. “We think this may help younger orcas feed more easily or it could also just be for fun,” she said. “Orcas are known for playing with their food.”
A target that comes to the surface
Sunfish are improbable animals. Flattened, nearly tailless, and capable of exceeding three meters in length and 2,000 kilograms in weight, they rank among the heaviest bony fishes alive. They move between depth layers but regularly drift up to the surface — to warm themselves after cold dives, to rest, or to let seabirds and cleaner fish pick off parasites. That surface habit leaves them exposed, and in the Gulf of California they are among the species orcas most often hunt and eat.
The first event unfolded in July 2024, when Ayres watched a group of orcas, including a juvenile, gather around a sharp-tail sunfish they had already killed. A female gripped the carcass by its broad tail fin, which offers a convenient handhold. A male then accelerated toward the pair. Just before he struck, the female let go. The impact blew the sunfish apart, scattering tissue through the water column.
What happened next is what makes the observation so suggestive. The juvenile began picking at the smaller fragments. The adults, by contrast, fed on what remained of the main body and left the scraps alone.
In September 2025, a second, independent encounter — this one filmed by Héctor Franz — followed the same script: one orca holding, another ramming, and the group feeding afterward on the shattered remains.
Processing, not killing
Because both sunfish were already dead when the ramming began, the researchers interpret the strike not as a killing blow but as a way of processing food. And it worked dramatically well. The impact caused extensive disintegration of the prey’s tissue, something the team describes as a substantial, high-energy breakdown rather than the ordinary tearing that accompanies orca feeding.
The precision of the maneuver points to cooperation. One animal stabilizes the target so its partner can line up an accurate hit, and the release is timed to the last moment before contact. That kind of coordination fits with what is already known about orca social behavior, which is organized around tight family groups and learned, culturally transmitted hunting techniques.
The authors suggest one plausible function is parental investment. Breaking a massive carcass into bite-sized pieces would make it far easier for a young animal to eat, and sharing prey across the group is well established. “Orcas often tear apart prey and share it with other members of the group, including calves and juveniles,” Ayres said. The fact that the juvenile in the 2024 event went straight for the small fragments while the adults ignored them lends that interpretation some weight.
Microbes in the mix
The study also raises a less obvious possibility. Sunfish are coated in a gelatinous layer known as the capsule, and both that layer and the skin beneath it support their own distinct microbial communities. When the tissue is shattered, those microbes are released into the surrounding water, where they can shift the local nutrient composition. The researchers propose that this fragmentation might bring sunfish and orca microbiomes into closer contact, potentially offering nutritional benefits or even playing a role in immune regulation. It is a speculative idea, but one that hints at how much ecological activity can be hidden inside a single predation event.
A fish that breaks differently
The encounters may also say something about the sunfish themselves. So far, this kind of explosive fragmentation has only been seen in sharp-tail sunfish (Masturus lanceolatus). That suggests the species’ tissue may have a particular structural response to high-energy impacts — one that larger sunfish species may not share. If so, the ramming strategy may be finely matched to a specific prey, much as other orca populations specialize in seals, salmon, or sharks.
Play, perhaps
None of this rules out the simplest explanation. Orcas are intelligent, social, and demonstrably playful, and the researchers acknowledge that the hold-and-ram routine could serve social purposes beyond feeding. It may, quite literally, be a game.
Settling the question will take more observations, and better ones. The team could not determine whether the same individuals were involved in both events, a gap that underscores how much depends on high-quality footage of dorsal fins and eye patches, the features researchers use to tell individual orcas apart.
“Collecting good identification photographs whenever possible is key: we are still seeing new techniques of how orcas hunt and process their prey,” Ayres said. “They’re one of the most iconic marine predators in the world, yet they continue to surprise us.”
For a species already credited with killing great whites for their livers and stealing fish off longlines, the sunfish trick is another reminder that the orca playbook is still being written — and that some of its most striking chapters may be authored simply because the animals can.
Featured image: Orca hunting rays in the waters off of the North Island in New Zealand. (Brian Skerry)
Notes
- Ayres, K., et al. “Fragmentation of Sharp-Tail Sunfish (Masturus lanceolatus) Caused by High-Impact Ramming Behaviour in Orcas (Orcinus orca).” Frontiers in Ethology, July 23, 2026. DOI: 10.3389/fetho.2026.1835536.
- Frontiers. “Orcas filmed ramming one of the world’s heaviest fish so hard it explodes, possibly for fun.” News release via EurekAlert!, July 23, 2026. https://www.eurekalert.org/news-releases/1136197