text: Sometimes walking in a straight line without tripping over with just two feet is enough of a challenge. So imagine the kind of coordination it would require if you had eight legs. Now scientists have unraveled how octopuses manage to keep track of all of their flailing limbs as they crawl over objects. The video above, recorded by researchers at the Hebrew University of Jerusalem, shows how that despite its body orientation (green arrow) the octopus can crawl in any direction (blue arrow) thanks to its flexible arms . Using high speed videos of octopuses as they negotiated obstacles, biologists at the Hebrew University of Jerusalem in Israel studied the cephlopods movement. They found that the orientation of the creature's body and the crawling direction are controlled independently in the brain. Male octopuses have a long, detachable penis in order to mate with females that are five times bigger than itself. When a female swims by, the male Argonaut sends his penis off to swim to the female and mate with her. In fact, the penis is a ball of sperm in a tentacle called a hectocotylus and females can be fertilised by more than one, by storing them in the mantle cavity. The male dies soon after his unique ordeal, whereas the female can mate several times and even store multiple hectocotyli in a special cavity until they’re needed. In the past, scientists that caught female specimens confused the attached penises for parasitic worms. The male mollusc won almost a third of votes in a survey set up by the Society of Biology to identify the strangest animal sex. The thrust comes from arms that push by elongation rather than arms that pull. This combined with they symmetrical arrangement of the arms around the body helps to give the marine creatures their extraordinary maneuverability. It is the first time scientists have been able to fully understand how octopuses are able to control their movements without a rigid skeleton. The findings may help scientists develop new ways for soft robots to move around and can also shed some light on how octopuses evolved in the first place. Professor Binyamin Hochner, who led the research, said: 'Octopuses use unique locomotion strategies that are different from those found in other animals. 'This is most likely due to their soft molluscan body that led to the evolution of 'strange' morphology, enabling efficient locomotion control without a rigid skeleton.' Octopuses are thought to have evolved from clam-like creatures in the mollusc family. But as they lost their hard protective shell, they seem to have evolved to move far faster than other members of the mollusc family like slugs or snails. The octopus was found to move by pushing with its legs rather than pulling while it could move in any direction regardless of the position of its body - something that humans find extremely difficult to do without falling over . Dr Guy Levy, a neurobiologist who also took part in the research at the Hebrew University of Jerusalem, said: 'During evolution, octopuses lost their heavy protective shells and became more maneuverable on the one hand, but also more vulnerable on the other hand. 'Their locomotory abilities evolved to be much faster than those of typical molluscs, probably to compensate for the lack of shell.' The researchers, whose work is published in the journal Current Biology, found that despite their large number of arms, octopuses do not move them in any rhythmical pattern like insects and millipedes do, for example. Speaking to the BBC, Dr Levy said the findings could help develop robots that can squeeze into difficult to reach spaces. He said: 'People want to build soft robots for medical purposes and rescue operations.'
target: Biologists at the Hebrew University of Jerusalem in Israel used high speed videos of octopuses crawling over objects to study how the animals move .
  Rather than pulling themselves along they use their legs to push instead .
  They can move in one direction while their bodies face a different direction .
  The findings could help scientists develop new types of rescue robots .