Some two years ago I published two posts on Vantablack, a black that is “blacker” than any black you see around. It was invented, created, by researchers using carbon nanotubes able to absorb 99.965% of light, practically creating a black void with no reflection to the point that a Vantablack BMW (watch the clip) was showcased but was not commercialised because it would be a risk for other motorists and pedestrians since it would be invisible (you would see a black hole in the shape of a car), as well as, I guess, because it would cost some 300,000$ of extra charge just for the painting.
Now marine researchers have stumbled onto a number of deep sea fish species that have evolved a skin that is as back as Vantablack. When they captured a fangtooth fish, see the photo, and tried to photograph it they were surprised to see that the camera could only capture the outline since the body of the fish was completely black, ie it was not reflecting light.
Measuring the absorption index they found it is 99.956% (that is very very close to Vantablack). Pretty amazing!
Turns out the fangtooth is not the only one, researchers have found 16 deep sea fish species that have evolved this type of non-reflective skin making them invisible in the depth (at this depth there is no light so several species have evolved a luminescence -basically a torch light- that let them see around but this light cannot illuminate these “Vantablack” species….).
We have created Vantablack using carbon nanotube. How have these fish species managed to create an equivalent light absorption capability? First, and very interesting, the researchers haven’t been able to find a close common ancestors to these species, meaning that they have evolved this capability independently from one another. The mechanism is pretty similar. First they have packed in their skin cells plenty of melatonin (the same molecule that is tanning our skin when we expose it to sunlight). Melatonin by itself is not sufficient. What they did was to create an organisational structure of their skin cells where the light reflected is reflected towards other cells over and over till it is (almost) all absorbed by the melatonin molecules.
Amazing to see what evolution can do, given sufficient time!