Wednesday, February 2, 2011

How the seahorse evolved its arched head and S-shape body to become a better hunter

By GRAHAM SMITH

Beguiling creature: The seahorse evolved its arched head and curved S-shape body to help it hunt and feed, scientists said


It's a question that has baffled marine scientists for centuries.

Now researchers have revealed that the seahorse evolved its arched head and curved S-shape body to help it hunt and feed.

The strange yet alluring fish is completely different to its closest relative, the straight-bodied pipefish.

Scientists wanted to find out why the delicate seahorse had gradually adapted its body.

While pipefish have to swim towards their tiny prey, seahorses sit and wait for small shrimps and fish larvae to come towards them and then strike.

The seahorse's flexible arched neck acts like a spring that stores energy allowing it to attack more distant prey, according to a study published in the journal Nature Communications.

It is a vital hunting technique to compensate for the fact the seahorse is a weak swimmer.

Lead researcher Dr Sam Van Wassenbergh, of the University of Antwerp, used high-speed film footage to watch seahorses operate at 66 times slower than their normal speed.


Modus operandi: The seahorse's flexible arched neck acts like a spring that stores energy allowing it to attack more distant prey


He then applied mathematical models to show how the 'bend and snap' of a seahorse's neck gives it a 20 per cent larger strike zone than the pipefish.

'They rotate their heads upward to bring their mouth close to the prey,' he said.
'Every extra millimetre you can reach becomes important because it means more food.'

The seahorse evolved into its beloved curved S-shape in order to use their bodies to obtain food in this way.

Dr Wassenbergh added: 'My theory is that you have this ancestral pipefish-like fish and they evolved a more cryptic lifestyle.'


source: dailymail


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