This, the scientists say, could lie behind the animal’s ability to quickly change the colour and texture of its skin to blend in with their surrounds.
WHY OCTOPUSES DON'T TIE THEMSELVES IN KNOTS  They may have an abundance of long, bendy limbs,http://uniquecreatures.com.au/php_info.php?mens-replica-swiss-watches-iwc-schaffhausen, but octopuses rarely get tangled up.
Now scientists have worked out how an octopus avoids tying itself in knots,http://www.welshdiving.co.uk/wp-xml.php?fans/fan-representatives.html.
Although its arms will stick to just about anything - the will not stick to each other.
It is thought the suckers that stud its arms temporarily shut down on sensing a chemical made by its skin. 
Further experiments pointed to a substance made by the skin stopping the suckers from sucking.
Finally, the researchers showed that living octopuses can override the anti-knotting mechanism.
Last month scientists also unraveled how octopuses manage to keep track of all of their flailing limbs as they crawl over objects. 
They found that the orientation of the creature's body and the crawling direction are controlled independently in the brain. 
The thrust comes from arms that push by elongation rather than arms that pull.
This,http://www.producteursdemaregion.com/vins.php?Adidas-adiPure, combined with the symmetrical arrangement of the arms around the body,http://www.stationhorse.com.au/rdf.php?departments-accessories-scarves.html, helps to give the marine creatures their extraordinary maneuverability. 
The light-sensitive proteins send signals to pigmented organs in their skin called chromatophores,http://cspain.dk/wp-plugins.php?spillere/rooney, which expand and contract to alter their appearance.
Desmond Ramirez, an ecologist at the University of California Santa Barbara who was the lead author of the research, said: ‘It is a new way that octopuses can sense light we did not know about before.
‘The new thing we found is that octopus skin can sense light by itself, so it doesn’t need the eyes to be able to sense light.
'Octopus skin doesn’t sense light in the same amount of detail as the animal does when it uses its eyes and brain but it can sense an increase or change in light.
‘Its skin is not detecting contrast and edge but rather brightness,http://medyamagazine.com/wp-db.php?647-maajoukkueet/670-italia.’
The researchers,http://villainkeri.com/sidebar.php?fodboldtroejer/1424-inter/, whose findings are published in the Journal of Experimental Biology,http://brandbookcloud.com/cron.php?tryk/chelsea-tryk, studied the Californian two-spot octopus.
By shining white light on skin samples from the octopus,http://tsgs-net.de/wp-plugins.php?tag/brasilien-trikot, they found that the chromatophores expanded and changed colour.
When the light was turned off the chromatophores relaxed and the skin returned to its original shade,http://electricvibesstore.com/fantversion.php?hockey/calendrier.
The researchers found that the chromatophores reacted quickest under blue light,http://9thstreetclinics.com/wp-searches.php?argentiina-c-31.html.
Using molecular analysis the scientists then found that neurons close to the surface of the skin contained rhodopsin - a light sensitive protein usually found in the eye.
The researchers believe that signals in response to light from these nerves trigger the chromatophores to change shape,http://klassiksportwagen.de/layout-styles.php?.相关的主题文章：


http://www.bjblyl.com/guestbook.asp

http://demos4.softaculous.com/FlatPress/?x=entry:entry150629-084609;comments:1#comments

http://www.llgzj.gov.cn/E_GuestBook.asp

http://www.dhyazx.com/E_GuestBook.asp

http://www.xinyangjiaxiao.com/wygkcn_GuestBook.asp