Air Date: Week of October 1, 2010

Researchers discover that sharks use their nostrils independently of one another to find food. Living on Earth’s Meghan Miner reports.

Transcript

GELLERMAN: It’s Living on Earth, I’m Bruce Gellerman. Just ahead – a new plan to make the Gulf of Mexico better than ever. But first, this Note on Emerging Science from Meghan Miner.

[SCIENCE NOTE THEME]

MINER: A state-of-the-art theater with surround sound gives the illusion that audio is just behind you, or to the right, or left. In the grand theater of the ocean, sharks experience surround-smell.

Scientists originally thought sharks used the intensity of smells to locate food. But, because smells don’t disperse evenly in water, marine biologists in Florida and Massachusetts wondered if this really was how sharks find their prey.

The researchers set up an experiment where sharks wore headgear that released scents of different concentrations- one nostril at a time. They found that even when an extremely diluted smell was sent to one nostril before a full strength odor was sent to the
other- the shark turned in the direction of the nostril that sniffed the smell first.

This showed that sharks use each of their two nostrils independently to pinpoint their food.

The finding may help explain why hammerhead sharks are considered the fastest and often the first sharks to reach prey. Hammerheads have nostrils on either side of their head, increasing the lag time between scents reaching each nostril- making them faster at honing in on dinner.

That’s this week’s Note on Emerging Science. I’m Meghan Miner.

 

Links

Researcher Jayne Gardiner’s website

Read the article in Current Biology