Scientists discover fish that can see with its skin, even after death

A new study revealed a bizarre characteristic of a hogfish that can change the colour of its own skin according to its surrounding environment with the help of special sensing cells even after they are no longer alive.

This study has allowed scientists to comprehend more about the nature and conduct of these fish alongside their adaptability to their surroundings. adapt.

A co-author of the study Lori Schweikert said: "They appear to be watching their own colour change."

Sonke Johnsen, another author of the study said: "In a way they can tell the animal what its skin looks like, since it can’t really bend over to look."

There are a number of sea creatures that can change their colour which helps them adjust as per the environmental temperature changes, attracting mates and providing camouflage, said researchers.

According to the researchers including those from the University of North Carolina, Wilmington in the US, cells on their bodies called chromatophores, contain pigments, crystals or tiny reflective plates, enabling these species to make changes in their colours rapidly.

The reef-dwelling fish — commonly found in the Atlantic Ocean from North Carolina to Brazil — does this to camouflage and escape predators, or maybe for social signalling.

Scientists were surprised to see that activity of colour changes even after their death.

In the new research published in the journal Nature Communications, experts used microscopy to determine the impact of light on different parts of the fish.

They found that light receptors, called SWS1, underneath the chromatophore, may be involved in the process.

Cells are sensitive to the light shining through colours expressed by chromatophores, specifically the wavelength of light that is present in their coral reef habitat, researchers said.

They also maintained that these receptors provide feedback to the fish on where and how changes are taking place in different parts of their skin.

Scientists wrote in the study: "By examining the morphology, physiology, and optics of dermal photoreception in hogfish [Lachnolaimus Maximus], we describe a cellular mechanism in which chromatophore pigment activity [i.e., dispersion and aggregation] alters the transmitted light striking SWS1 receptors in the skin."

"The animals can literally take a photo of their own skin from the inside. In a way they can tell the animal what its skin looks like, since it can't really bend over to look," Dr Johnsen explained.

"Just to be clear, we’re not arguing that hogfish skin functions like an eye," Dr Schweikert said, adding that "eyes are capable of more than just detecting light."