"We define culture as a behavior that is acquired by imitation and passed on in a population," said Michael Krutzen, of the University of Zurich in Switzerland, who led the new research. "We think this behavior is an example of that. It's very exciting."
Krutzen and his colleagues believe the dolphins, which live in Shark Bay off the west coast of Australia, wear the sponges while foraging for small fish, crustaceans and other food along channels in the sea floor to protect themselves against sharp coral and stinging critters such as stonefish. It's a trick that appears to be almost exclusively passed from mothers to daughters.
"They wear them like a glove," Krutzen said. "When they go down to the sea floor to probe for prey, there are lots of noxious animals down there. By using the sponge, it protects them."...
The behavior may be passed almost exclusively to females because foraging along the seabed is a solitary activity, and males tend to spend most of their time traveling in groups searching for mates.
heheh. no real surprise there