We know that octopus is one of the world’s most intelligent marine creatures. They can change the color and texture of their skin to mimic that of a rock or apiece of coral. As if that was not enough, researchers have discovered that octopuses can “see” with their skin, completely bypassing their eyes and brains. The discovery confirms previous speculations.
Octopus skin contains light-sensitive proteins
A team of scientists led by Desmond Ramirez of the University of California at Santa Barbara found that octopus skin contains the same light-sensitive proteins (opsins) usually found in eyes. Ramirez said that octopus skin’s perception is not as keen as its eyesight, but it does present evidence that their skin can detect light even without any input from the central nervous system.
Scientists found that its skin does not sense light in the same detail as octopus does using its eyes and brain. The animal’s skin can sense a change in the brightness of light, but is unable to detect contrast and edge. Findings of the study were published in the Journal of Experimental Biology. Mr Ramirez and his colleagues cut off pieces of skin from a California two-spot octopus to see if it responds to the light.
Octopus skin more sensitive to blue light
When they kept the skin in dim red light or darkness, it stayed pale. But as soon as they turned on the lights, pigmented organs in the skin called as chromatophores swiftly expanded and changed color within a matter of seconds. The skin returned to its original hue when they switched off the light. Scientists said they were not expecting such a quick reaction.
Ramirez said that light sensors are connected to the chromatophores, allowing the skin to give an appropriate response without any help from the brain or eyes. They discovered that octopus skin contains a compound called rhodopsin, which is usually produced in the eyes. It helps the skin detect light. Scientists said that octopus skin is more responsive to the wavelength of 480 nanometers, which is the wavelength of blue light. It’s probably because rhodopsins absorb the light of this wavelength best.