[thedoc (OP)]

Sharks are known for their ability to follow a scent in the water to their next meal – and now researchers in Florida have discovered how they do it.
Read the whole story on our website by clicking here

[Kerry]

I recently got to speak to a guy from Bath University who was studying the sharks' olfactory system - really interesting stuff.

There's a video press release on the Bath website http://www.bath.ac.uk/play/video/1272968340 [nofollow] but the original press release appears not to be so I've pasted the most relevant bit below:

The researchers did a CT scan of a shark’s head from the Natural History Museum’s collection. The scan was used to make an accurate model of the head and nasal cavity with a 3D printer...

This is the first time a detailed model of a hammerhead shark’s head has been made to study the creature’s amazing sense of smell...

Dr Jonathan Cox said: “Whereas humans use their lungs like a bellows to inhale air through their noses to smell, the hammerhead shark smells as it swims forwards, propelling water through its nose.

“The nasal cavity of the hammerhead is like a labyrinth of pipes, with a central U-shaped channel and lots of smaller channels leading off it. The smaller channels contain the olfactory receptors, and so we’re looking at how the water flows through these channels as the shark swims forwards.

“Sharks sweep their heads from side to side when they swim, so to simulate this we change the angle of the head model in the tank and observe the flow at each angle.”