What happens at the bottom of the sea? There is not much light there to begin with. Most creatures produce their own light, known as bioluminescence. It is used to distract potential prey or to find a partner. But it can also give away nearby predators. That’s why they develop incredible camouflages. Like fish that absorb light and disappear.
Smithsonian scientists discovered it. It is one of the blackest materials known: the skin of certain fish. They absorb light so efficiently that even in bright light they look like silhouettes with no recognizable features. They disappear in the darkness of the ocean, even surrounded by bioluminescent light.
Running in front of the light
The research results have just been published in “Current Biology”. Karen Osborn and Sönke Johnsen lead the research team. They explain that some fish absorb almost all of the light that reaches their skin, so only 0.05% is reflected. Imitating this strategy could help engineers develop more affordable, flexible, and durable ultra-black materials. You would use them in optical technology, in telescopes and cameras, or even for camouflage.
Osborn became interested in the skin of the fish for the first time when he tried to photograph some eye-catching black fish. They used sophisticated devices with the latest technology. But they couldn’t catch a detail of these fish. “It didn’t matter how you configured the camera or lighting, they just absorbed all the light,” Osborn said in a statement.
These fish are extremely black: blacker than black paper, blacker than tape, blacker than a new tire. Very useful for survival on the ocean floor.
Melanin in your skin
Light absorption depends on melanin, the same pigment that colors human skin and protects it from sunlight. It is abundant on the skin of ultra-black fish.
“They made a super efficient and super thin light trap,” says Osborn. «The light does not recover; Light does not go out. It just goes to that level and it’s gone.
These fish are not the only animals that capture enough light to create an ultra-black surface. Ultra-black feathers and scales have been found in some birds and some butterflies. They contrast with colored areas and make colors appear more vivid. These animals create the effect by combining a melanin layer with structures that capture light, such as. B. small tubes or boxes. In the deep sea with limited resources, ultra-black fish seem to have developed a more efficient system, said Osborn. “This is the only system known to us that uses the pigment itself to control light that is not initially absorbed.” This ultra-blackness based on melanosomes appears to be a common strategy in the deep sea. Osborn and his team found the same different pigment patterns in 16 species of fish that absorb and disappear.
It is clear that they like to go unnoticed. And that they probably hate photos. Especially when they are with flash.