|Octopuses handed Rubik's Cubes|
Twenty-five octopuses have been given Rubik's Cubes in a research study but marine experts don't expect them to crack the puzzle.
Instead they want to determine if the sea molluscs have a favourite tentacle for picking things up.
Scientists believe the intelligent sea creatures have a preferred arm out of eight that they use to feed and investigate with - just like humans are right or left-handed.
They are testing the theory with a month-long observation project at 23 Sea Life Centres across Britain and Europe by giving them food and toys to play with.
Claire Little, marine expert at the Sea Life Centre in Weymouth, Dorset, said the study could also help to reduce stress among octopuses.
She said: "It will be very interesting to see the results.
"Uniquely, octopuses have more than half their nerves in their arms and have even been shown to partially think with their arms.
"We hope the study will help the overall well-being of octopuses. They are very susceptible to stress so if they do have a favourite side to be fed on, it could reduce risk to them."
A diagram of an octopus will sit alongside the tanks with the arms on the right labelled R1, R2, R3 and R4 from front to back. The left arms will be numbered in the same way but with an L instead of an R.
When items such as a ball, a jam jar and Lego bricks are dropped into the water visitors can note down which arm was closest to the object and which arm picked it up.
If the octopus uses several arms, they must write them all down but in the order they touched it.
Staff at the centre will also do the same during feeding time.
Miss Little said: "Visitors will be handed a form asking them to participate in our study.
"We will add the results to all of the data that has already been collected about octopuses. It will also help towards solving the mystery of handiness in the animal kingdom."
The results will be analysed by Sea Life Centre biologists and the results will be announced in the autumn.