A pointy-snouted reef fish called the hogfish can change from white to spotted brown to reddish depending on its surroundings. PHOTO BY COURTESY OF DEAN KIMBERLY AND LORI SCHWEIKERT/SWNS
A species of fish can see with its SKIN as well as its eyes, reveals new research.
The amazing discovery was made after a scientist noticed something unusual during a fishing trip.
Researchers say the species’ ability to “literally take a photo of their own skin from the inside” could pave the way to new sensory feedback techniques for devices such as robotic limbs and self-driving cars.
She reeled in a pointy-snouted reef fish called a hogfish and threw it on board.
But when Dr. Schweikert went to later put it in a cooler she noticed that its skin had taken on the same color and pattern as the deck of the boat.
A common fish in the western Atlantic Ocean from North Carolina to Brazil, the hogfish is known for its color-changing skin.
Dr. Schweikert says the species can morph from white to mottled to reddish-brown in a matter of milliseconds to blend in with corals, sand or rocks.
But she was still surprised because this hogfish had continued its camouflage even though it was no longer alive.
It made her wonder if the hogfish could detect light using only their skin, independently of their eyes and brain.
They showed that the gene is different from the opsin genes found in their eyes.
Other color-changing animals -such as octopuses and geckos – have been found to make light-sensing opsins in their skin, too.
One theory is that light-sensing skin helps animals take in their surroundings.
But Dr. Schweikert said new findings suggest another possibility, that they could be using it to view themselves.
In the new study, Dr. Schweikert and her colleagues teamed up to take a closer look at hogfish skin.
They took pieces of skin from different parts of the fish’s body and took pictures of them under a microscope.
The research team used a technique called immunolabeling to locate the opsin proteins within the skin.
They found that in the hogfish, opsins aren’t produced in the color-changing chromatophore cells. Instead, the opsins reside in other cells directly beneath them.
Images taken using a transmission electron microscope revealed a previously unknown cell type, just below the chromatophores, packed with opsin protein.
The research teams estimated that the opsin molecules in hogfish skin are most sensitive to blue light – which happens to be the wavelength of light that the pigment granules in the fish’s chromatophores absorb best.
The research team says the work is important because it could pave the way to new sensory feedback techniques for devices such as robotic limbs and self-driving cars that must “fine-tune” their performance without relying solely on eyesight or camera feeds.
Produced in association with SWNS Talker
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