At the bottom of the ocean, where the sun’s light barely reaches, various fish live that share a very particular characteristic: their skin is one of the blackest materials that exist. One of them is the Pacific black dragon (Idiacanthus antrostomus), an ultra black fish that absorbs 99.5% of light.
Now, a team of researchers led by the Washington Smithsonian National Museum of Natural History and Duke University has discovered the secrets of his skin, revealing why it is able to absorb virtually all the light it receives.
Karen Osborn, a zoologist at the Smithsonian National Museum of Natural History in Washington, first became interested in the skin of these animals when she attempted to photograph them. “It didn’t matter how you set up the camera or the lighting, they just absorbed all the light.”, explains the researcher.
In the depths of the ocean, where the sunlight barely reaches, There can be no better camouflage than black. In this way, organisms can be confused with the environment and go unnoticed by predators. “If you want to blend in with the infinite blackness of your surroundings, absorbing every photon that hits you is a great way to do it.”Osborn points out.
Now, these scientists have discovered what is the secret that allows fish like the Pacific black dragon to reflect 99.5% of light. The blackness of your skin depends on melanin, the same pigment that gives color to human skin. The point is that in ultra-black fish, this pigment is not only abundant, but also uniquely distributed over the entire surface.
In these animals, the size, shape, and arrangement of melanosomes (the organelles in the skin that contain melanin) cause them to direct all light that they do not directly absorb to neighboring melanosomes within the cell. “Effectively, what they have done is make a super efficient and super thin light trap“Osborn claims.
This finding, published in the journal Current Biology, is very interesting for different applications. And it is that, although there are already blacker materials (the Vantablack reflects 99.96% of the light), the skin of these fish stands out for its thinness and efficiency.
Making ultra-black materials is very useful for sensitive optical equipment such as telescope cameras, as they prevent reflections from creeping in that spoil the images. It also serves for the development of camouflage technologies for military vehicles or aircraft, as well as for application in works of art.