Scientists say mystery underwater sound is farting fish
Biologists baffled by a mysterious, underwater sound think it may be herrings farting.
No fish had previously been known to emit sound in such a way, reports the New Scientist.
But a team from the University of British Columbia in Vancouver say the noise matches bubbles coming out of a herring's anus.
"It sounds just like a high-pitched raspberry," says Ben Wilson of the university.
Mr Wilson and his colleagues cannot be sure why herring make this sound, but initial research suggests that it might be a means of communication.
Wilson points that, unlike a human fart, the sounds are probably not caused by digestive gases because the number of sounds does not change when the fish are fed.
The researchers also tested whether the fish were farting from fear, perhaps to sound an alarm. But when they exposed fish to a shark scent, there was again no change in the number of farts.
Finally, three observations persuaded the researchers that the farts were most likely produced for communication.
Firstly, the number of farts per fish increased when more fish were added to the tank. Secondly, herrings are only noisy after dark, suggesting they might be a way of finding each other in the dark. And finally, most other fish cannot hear the noises.
Biologists baffled by a mysterious, underwater sound think it may be herrings farting.
No fish had previously been known to emit sound in such a way, reports the New Scientist.
But a team from the University of British Columbia in Vancouver say the noise matches bubbles coming out of a herring's anus.
"It sounds just like a high-pitched raspberry," says Ben Wilson of the university.
Mr Wilson and his colleagues cannot be sure why herring make this sound, but initial research suggests that it might be a means of communication.
Wilson points that, unlike a human fart, the sounds are probably not caused by digestive gases because the number of sounds does not change when the fish are fed.
The researchers also tested whether the fish were farting from fear, perhaps to sound an alarm. But when they exposed fish to a shark scent, there was again no change in the number of farts.
Finally, three observations persuaded the researchers that the farts were most likely produced for communication.
Firstly, the number of farts per fish increased when more fish were added to the tank. Secondly, herrings are only noisy after dark, suggesting they might be a way of finding each other in the dark. And finally, most other fish cannot hear the noises.