Scientists have discovered a super-black fish that absorbs almost all of the light that hits them, allowing them to effectively hide themselves in the deepest and darkest parts of the ocean,media reported. This appears to be a more effective way to avoid arrest than other animals, and the discovery could help develop future optical and camouflage technologies.
The discovery was made by a team led by scientists from The Smithsonian and Duke University. The study found that the fish absorb 99.5 percent of light, and even in direct light, they look like silhouettes. And it’s not just a species — so far, the technique has been found in 16 different, distant species.
These findings make sense. These fish live in depths of the ocean below 200 metres, not in the dark sun. Many animals have adapted to this environment by producing their own light, bioluminescence, to attract food or mates, or to illuminate predators and prey hiding in the dark.
So for other species, being in the dark is an effective survival strategy. Absorbing almost every photon that shines on you is a good way to improve your chances of not being eaten without scaring your own food.
The team found evidence that the mechanism was helpful to fish in both ways. The first is the super-black scale, which uses camouflage to avoid arrest — and its last trick is that, if caught, the separable scales can help it slip away.
Meanwhile, the Pacific Black Dragon is a scary-looking creature with super-black skin and glowing bait. Their own light does not reflect on the skin to scare off prey. The creature even has transparent anti-reflective teeth. To find out how the fish absorbed light so effectively, the team studied specimens from deep trawls. The key they found was melanin, a pigment that absorbs light and, to varying degrees, darkens human skin.
It turns out that these fish have very high levels of melanin in their skin and are arranged in a very special way. Pigment cells are made up of dense intervals called melanosomes, which rarely waste light because of their size, shape and position. They do not absorb themselves, but turn to other melanosomes.
Karen Osborn, lead researcher on the study, said: “What they’re actually doing is creating an ultra-efficient, ultra-thin light trap. Light does not bounce, it cannot pass. It just disappeared after entering this. “
The same principle applies to other ultra-black materials, both natural and man-made, but the team says the fish-type material is much more efficient.
The team noted that the melanin-based system used in the fish was much smaller and the mechanical structure was much simpler. This helps to design darker, thinner, more durable and cheaper ultra-black materials than it is today.
“This is the only system we know of that uses the pigment itself to control the light that was initially not absorbed, ” says Osborn. If you fit the size and shape of the absorbent pigment, you can achieve the same absorption, and the cost may be much lower, making the material less fragile, rather than creating a structure that captures light. “