Now many people are seeing dolphins conching.
"In the last four months alone, the research team have seen and photographed the behavior no less than six times, possibly even seven," Murdoch Cetacean Research Unit researcher Simon Allen was quoted as saying in the press release.
"If - and that is a big if - we are witnessing the horizontal spread of this behavior, then I would assume that it spreads by an associate of a 'conching' dolphin closely observing the behavior and then imitating it," he added. "It is a tantalising possibility that this behavior could spread before our very eyes - over a field season or two - and that we could track that spread."
No one has ever before documented the spread of a learned behavior through a population of these marine mammals over a short period of time.
The researchers also hope to learn more about how the dolphins actually use the shells.
"As yet, we don't know if dolphins simply pursue fish into the' refuge' of the large, empty conch/bailer shells or whether they actually manipulate the shells prior - perhaps turning them over so that the opening is facing up in order to make them 'appealing' to fish as a place to hide from the jaws of death," Allen explained.