Evolutionary biologists at the University of California, Santa Barbara have confirmed that octopi can “see” without using their eyes. Indeed, octopus skin apparently contains the pigment proteins found in eyes – making it responsive to light.
“These clever cephalopods can change color thanks to specialized cells called chromatophores, which are packed in their thousands just beneath the skin surface,” explains Mo Costandi of The Guardian.
Image Credit: Albert Kok, Wikipedia
“Each of these cells contains an elastic sac of pigmented granules surrounded by a ring of muscle, which relax or contract when commanded by nerves extending directly from the brain, making the color inside more or less visible.”
A number of other species have skin that contains opsins and is sensitive to light. However, the above-mentioned study, published in the Journal of Experimental Biology, offers the first clear evidence that octopus can also detect light, while hinting at plausible mechanism by which chromatophores respond to it.
“It’s interesting to speculate about how octopi camouflage themselves. We try to understand how a colorblind animal can appropriately match its appearance to a specific environment,” said Patrick Gill, a Principal Research Scientist at Rambus.
“It could be that the color-sensitive opsins Mr. Ramirez and Dr. Oakley found in octopus skin are behind the octopus’ ability to match its surroundings. If so, this would be a great biological example of useful low-resolution light sensing accomplished by a tiny, specialized structure.”
As we’ve previously discussed on Rambus Press, many animals have evolved integrated sensing capabilities throughout their bodies. To be sure, tiny, simple sensory neurons sprinkled throughout various organisms frequently report on local conditions more effectively than a few dedicated, but isolated, sense organs.
“Facilitating just the right amount of sensing where it’s needed is one of the objectives of our lensless smart sensors (LSS), as it enables our technology to help autonomous electronic devices navigate the world’s complexity,” added Gill.
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