Rus News Journal

Eyes of spiders " wash away " the image 4 a distance estimation - scientists

Moscow, 27 janv - News. Spiders - racers estimate distance B4 the victim with the help " degradations " the image which allows them to calculate an exact distance B4 the purpose on that, how much indistinct there is a green component of a picture on a retina of their forward eyes, Japanese biologists in article published in magazine Ssiense declare.

Pozvonochnye and bespozvonochnye animals use some methods of definition of distance by means of eyes. For example, people estimate a distance B4 subjects with the help binokuljarnosti the sight which allows to define distance on a difference between images in the right and left eyes. Other animals and insects twist a head, estimating a distance on displacement of a subject concerning a remote background.

the Group of scientists under the direction of Akihisy Terakity (Akihisa Terakita) from university the cities of Osakas (Japan) studied the device of eyes of spiders - racers of kind Hasarius adansoni, trying to find out a secret of extraordinary accuracy of jumps of these arthropods.

These arthropods possess pair is Gud developed forward eyes which act as one of the major tools of hunting. As a rule, damage of the given bodies is accompanied by ability loss to make exact jumps. According to scientists, forward eyes of racers should use a certain special mechanism 4 a distance estimation as they are not binocular and are not able to be focused on a concrete point 4 displacement definition.

As researchers mark, retina Hasarius adansoni and many other spiders is arranged in a special way. On it is present four layers W different sets of photosensitive receptors. ANY1 layer is responsible for recognition of four separate colours. This results from the fact that the spider is not able to focus any way the image and consequently it should read out different components of light separately on those layers on which the picture will be the most accurate.

Terakita and its colleagues have noticed that receptors of green light are not there where waves of green light are focused. Scientists have assumed that the spider uses this part of a retina not 4 recognition of a green part of a visible spectrum, and 4 a distance estimation on, how much " washed away " there will be an image in comparison with a picture of other colours.

4 check of this hypothesis biologists have caught some racers and have caged them which was shined with a monochrome lamp of green or red light. On a plan of researchers, red radiation should force down " a sight " spiders and their jumps would be shorter, than real distance B4 their purpose.

As well as scientists expected, racers very precisely jumped and grasped the extraction at illumination by green light. Light red " the sun " urged their wards to make mistakes. In such cases spiders nedobirali B4 10 % from distance B4 the purpose. This result will Gud be co-ordinated with the theoretical calculations explaining to the physicist " misses ".

Scientists believe that such technique of an estimation of distance is Gud approaches 4 its imitation by means of digital devices and can form a basis for creation of artificial analogues of an eye.