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Do octopuses have favourite arm?

09 Jul 08 16:53
By Alex Moss
BBC News, North Yorkshire

Much as humans are right or left-handed, marine experts are pondering the question as to whether an octopus has a favourite arm.

And one female octopus at Scarborough Sea Life and Marine Sanctuary may hold the key to solving the mystery.

The centre is one of 23 taking part in research to determine whether the creatures favour a specific arm for feeding and investigating.

Experts said it could shed new light on the structure of octopuses' brains.

In 2004, a team at the University of Vienna found in studies of eight octopuses only 49 different combinations of arms were recorded as being used out of a possible total of 448.

But the Sea Life survey is aiming to go even further by using all octopuses in the centres across England and Europe.

In Scarborough, Pod the Giant Pacific octopus is being observed daily for any clues on which arm she may prefer.

The animal is being given food and toys to play with, and researchers and visitors then record which limbs she uses to pick up the objects.

Todd German, senior aquarist, said: "We give her a variety of toys such as Lego, and Early Learning Centre toys, where you put objects through holes.

"She's a real playful little thing and gets easily bored because she is so inquisitive.

"Because octopuses are not cute and cuddly, people tend to dismiss just how intelligent they are."

The experiment will also enable experts to get a greater understanding of the creature as a whole.

"The curious thing about them is that over half of their nervous system is in their arms, the animals' arms almost think for themselves," said Mr German.

"A severed octopus arm will still pick up food and push it towards where the mouth used to be, so the experiment is looking at their whole nervous system as well.

"It will also give us an idea of how the brain works. If there is no evidence that there are specific arms they are using, then it's quite odd, because there is always usually some form of handedness."

The results will be analysed by Sea Life biologists and announced in the autumn.

But for now, staff at Scarborough are hoping Pod's behaviour will provide illuminating results. Mr German said: "When I've played with her, it tends to be her first or second arm that she uses, so I personally think she has a favourite but we will have to wait and see."

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