Scientists have long wondered how jumping spiders such as this one get visual information quickly and accurately enough to catch flies. In a study published in the journal Science in January, Takashi Nagata of Japan’s Osaka City University and his colleagues reported that jumping spiders compare focused and unfocused images to perceive depth—with a color twist. The investigators knew that the two innermost layers of a jumping spider’s two principal eyes (seen here as the two largest eyes) are tuned toward green light. But they focus that light differently: the deepest layer focuses green light clearly, and the second layer receives defocused images. To test whether differences in the two layers were important for depth perception, Nagata’s team shone green light on the spiders and tempted them with tasty flies. The spiders made spot-on jumps. Yet when the team bathed the prey in red light that did not contain green wavelengths, the spiders consistently missed their prey.

This article was originally published with the title What Is It?.

4 Comments

1. 1. promytius 06:44 PM 4/7/12

   so where are the spiders getting green light? Wouldn't they then also live around green lights, you know, because it's hard for a spider to carry just about anything.

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2. 2. And Then What? 07:04 PM 4/7/12

   So the moral of this story is:
   When surrounded by jumping spiders try to look as Red as possible.
   

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3. 3. Xopher425 08:14 PM 4/7/12

   Green light is in white light - their eyes filter out the other colors and see that wavelength. Green plants are green because they absorb/use all the wavelengths BUT green, reflecting it back. If you put plants under only green lights, they'll die due to inability to photosynthesize.
   
   I adore jumping spiders - they're handsome little guys.

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4. 4. verdai 03:49 PM 4/24/12

   just like us.

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