New studies confirm that certain octopus species actually see through their skin rather then eyes. The same proteins found in eyes are being found throughout their skin. These light sensitive proteins, called opsins, are found universally in the eye lenses of animals and humans. Octopi do have eyes, but this new discovery also shows that their skin aids in their visual input. Where eyes see edges and depth, their skin detects different wavelengths of brightness, allowing them to mimic certain colors, patterns, and textures in their environment; even mimicking the shine of reflecting water.
According to the discovery, the octopi see in another unexpected ways as well. They do not use the central nervous system to transmit visual data at all. In the study, the scientists were able to separate the octopus brain from the skin organ, thus proving neither was working together. The proteins within their skin actually translate light into color, allowing them to camouflage to their environment. Octopi are able to change color and texture to adapt to their surroundings.
Already, octopi are considered incredible evolutionary animals. They have multiple large brains and boneless body structures. In addition to their seeing skin, they also have two main eyes that function as well. The ability for skin to change color due to different light receptor proteins in the skin has been seen in a few species of cuddle fish and squid as well. Their skin sees brightness rather than texture and depth like human eyes do. It allows these octopus and squid species to survive in the harsh conditions of the deep where light and light reflections play an important role in predator prey relationships.
Furthermore, these light and color changes actually act as a form of communication for the octopus. Scientists are also now considering whether certain mollusks, squid, and octopi share a common ancestor. And if so, what does that tell us about the evolution of underwater life? Or did these species just evolve similarly due to similar environment? How does skin sensitive to light effect the behaviors of these animals, and what do they communicate?
The skin of other animals do detect ultra violet wavelengths however, this ability is most commonly used to protect the skin from ultra violet light damage. Where as with these octopi, the skin senses the light and triggers the bodies of the octopi to camouflage to their surroundings. They have evolved this extra sight as a survival technique against predators as well as an aid in their own hunt for prey.
The new discovery of octopi seeing with their skin challenges scientists to relook at other similar species of the ocean as well, like squid. Scientists have known for years the evolutionary masterpieces octopi are; with this new study’s findings, it has become even more clear how advanced these animals truly are; showing that these primitive animals may actually have an advanced form of communication.
Written by Audrey Madden
Yibada:Some Octopus See With Their Skin, Detect Light Using Eye Proteins: Study
Science Times: Seeing With Its Skin—How An Octopus Can Live In the Deep
Science News: Octopuses can ‘see’ with their skin
Flickr Photo by – Smithsonian’s National Zoo – Creative Commons License