Marine biologists have documented Indo-Pacific bottlenose dolphins (Tursiops aduncus) using large sea shells to hunt for fish off the coast of Queensland, Australia — only the second place in the world where this behavior, known as shelling, has ever been recorded.
This image shows a shelling event that occurred on January 4, 2019. Image credit: Levengood et al., doi: 10.1111/mms.70252.
Shelling involves a dolphin lifting a large, empty gastropod shell — in this case the bailer shell (Melo amphora), a species that can grow to the size of a football — to the water’s surface and tipping it to drain out a fish hiding inside.
The behavior is considered a form of tool use, a rare trait among animals that has drawn scientific interest for what it might reveal about cognition and culture in the wild.
The new observations were made in Hervey Bay, part of the Great Sandy Marine Park, far from Shark Bay in Western Australia, the only other location where the tactic had previously been confirmed.
“We were on a research boat off Hervey Bay when we spotted a dolphin raising something large out of the water. I started screaming because I know what shelling looks like,” said Dr. Alexis Levengood, a researcher at the University of the Sunshine Coast.
“It’s a hunting behavior where dolphins chase fish into large empty shells, bring the shell to the surface and then shake it to drain the fish into their mouths.
“We were able to record footage and take photographs of dolphins shelling in the Great Sandy Marine Park, which is the first published record of it on the east coast of Australia.”
The researchers recorded two shelling events in 2025, along with older photographs supplied by a local whale-watching operator dating back to 2013.
In the first sighting, on July 6, 2025, a lone adult female nicknamed Stevie Nicks was seen maneuvering a bailer shell at the surface before eventually dropping it.
The second sighting, on October 1, 2025, was more revealing: a mother dolphin named Maserati surfaced with a bailer shell containing a fish, then dropped the shell to chase her prey; minutes later, in the same spot, her calf, Bentley, was seen picking up the shell and mimicking the behavior.
The sequence offers the first evidence suggestive of the skill being passed down directly from mother to calf, a pattern known as vertical social transmission.
“We saw the mother surface with a shell, the fish inside escaped and the dolphin dropped the shell to chase the fish,” Dr. Levengood said.
“Then, minutes afterwards, the dolphin calf picked up the shell and held it the same way as its mother.”
“Our footage provides the first potential evidence of maternal social transmission — a process by which offspring learn behavior by observing the actions of its mother.”
