Octopus’s skin can detect light

According to a new research by the University of California which was published in the Journal of Experimental Biology, an octopus does not need any eyes to sense light because their skin is capable of doing that for them. It was found that the octopus skin has a certain pigment proteins that are normally found in the eyes. This is he pigment that makes the eyes light responsive, its presence in the octopus’s skin renders the skin responsive to light as well.

An octopus has two eyes and four pairs of legs and its body is bilaterally symmetrical. It has no skeleton but is extremely skilled in camouflage; an octopus is capable of changing the texture and color of its skin in a moment’s notice. This allows them to be very skilled hunters and helps them to gel in with their surrounding flawlessly while they wait for their prey or in order to evade predators.

The lead author of the study Desmond Ramirez of the Department of Ecology, Evolution and Marine Biology (EEMB) said that the new research indicates that octopuses rely on their vision for changing their color.  The Chromatophores in the skin of the octopus helps them to achieve camouflage effectively in less than a second. According to Ramirez, “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.”

Back in 1960s it was made clear with a study that Chromatophores react to light which implies that they can be controlled without the help from brain. For this research, several skin samples of The California two spot octopuses were taken. It was found that when the octopus skin was subjected to continuous bright light of high intensity, the Chromatophores expanded rapidly and remained in that condition as long as light was shone on it.

On the other hand, when Red light was shown, the muscles contracted rhythmically but did not expand the chromatophores which showed the difference in its behavior corresponding to the light. According to Desmond Ramirez, the lead researcher, this process indicates that light sensors are linked with the chromatophores and this makes possible a response without input from the eyes or brain. This process was named Light-Activated Chromatophore Expansion (LACE) by researchers. The research was meant for octopuses but there are a many other creatures that can see using their skin. Several others contain ospins in their skins which makes them sensitive to the light around them.