As human beings explore the deep sea more and more, there are also more and more abundant deep-sea fish that we have discovered. Interestingly, the appearance of these deep-sea fish is more bizarre than the other, and even a little bit unlike the creatures on Earth. Therefore, there is a saying circulating on the Internet: No one in the deep sea looks at it anyway, and it is easy to grow.
However, biologists have found that these fish are not only ugly, but also black. In the deep sea of hundreds or even thousands of meters, they are almost integrated with the dark environment.
(Photo caption: Snap of the horned goldeye seabream)
You think they just look black in the dark, dark depths? You're wrong, even when you come to the sun, they can still make your eyes black, so that the bag adults feel like a white A4 paper. These deep-sea fish prove with their own bodies that you know nothing about blackness.
Many people think that sea creatures disguise themselves by making themselves transparent. But in fact, even in the dark deep sea, these fish still have to disguise themselves through black.
This blackness is not caused by lack of light, but by their skin. We know that the brightness of an object that does not emit light depends on both how strong the light on its surface is and how much light its surface can absorb. If an object can reflect all of its natural light, then it appears; if it can absorb all of its natural light, that is. And these fish can use their skin to absorb almost all the light.
(Photo caption: Still image of the horned goldeye seabream)
Karen Osborn, a zoologist from the Smithsonian's National Museum of Natural History, after several failed attempts to photograph these fish caught from the deep sea, said helplessly: "No matter how you adjust the camera settings or the light, they can absorb all the light." "Some even joke that even when illuminated with a blinding spotlight, they look like silhouettes.
But on the other hand, she instead became interested in studying the skin of deep-sea fish. In the lab, she and her colleagues carefully analyzed 18 fish caught in trawls in the Gulf of Mexico or Monterey Bay, California. They found that the appearance of these fish was able to absorb the light that was shining on them with great efficiency, and the reflectivity was even less than 0.6%, and the reflectivity of 16 of them was even less than 0.5%.
(Photo caption: Pacific Black Arowana)
What is this concept? Let's put it this way, even the pure blackboard in schools in the 90s still has a reflectivity of 7%. The asphalt on the road also has a reflectivity of 4%, which is why you can see the convexity between the asphalt. In other words, the appearance of these fish is darker than asphalt.
At present, biologists have found the darkest part of the body of terrestrial creatures, which is the feathers of the gorgeous bird of paradise of Vogelko. At first glance, you may not be able to see how dark its feathers are.
But when it unfolds all its feathers...
This is the real black, you can't see the gap between every feather. According to biologists, the feather absorption rate of the gorgeous bird of paradise of Voogkopp is amazing, and almost all the light is absorbed, so you can't even see the overlapping parts between the feathers. Biologists believe that such black feathers can better set off the brilliant colors of other parts of it, thus gaining the favor of the opposite sex.
(Photo caption: The moving bird of paradise gives you more insight into how black its feathers are)
Osborn et al. found that almost all of these fish had such an amazing rate of light absorption. Moreover, this astonishing black color spreads throughout almost every part of their bodies, allowing them to completely hide in the dark environment of the deep sea, and scientists have compared their appearance to the invisible cloak of the deep sea.
"Such a low reflectivity makes these deep-sea fish indistinguishable from the blackest known animals, and they even surpass ultra-black butterflies (0.06%-0.5%), the same as the blackest bird of paradise (reflectivity 0.05%-0.31%)," they write in the paper. ”
Even, even though human technology has been developed to this day, it has barely been able to create objects as black as them, that is, the famous Vantablack (Universally Alligned Nano Tube Arrays, translated as vertically arranged carbon nanotube arrays).
(Photo caption: Black World Record Vantablack, just look at the bird of paradise GIF, you can understand why Vantablack made a bumpy mask looks like a flat shape out of PS)
Vantablack, a British company created in 2012, absorbs light at a rate comparable to the skin of these deep-sea fish. However, this is something that humans have only been able to do with today's technology, and these fish have evolved such skins by the power of nature tens of thousands of years ago!
The researchers pointed out that the reason why these fish are so black is also closely related to their living environment. Although there is no sunlight in the deep sea and it is dead dark, some predators have evolved the ability to shine. For example, the Yohyd's black trout has evolved a glowing organ above its head to illuminate the sea ahead, so it is called "lantern fish" by some people.
(Photo caption: José's black trout)
If it is illuminated by the light emitted by this predator, then the time of death is probably not far away. So, in order to avoid these predators, these deep-sea fish grow darker and darker.
The reason is understood, but then there is a question: how did these deep-sea fish become so black by the power of nature?
When the researchers studied the outer structure of these fish, they found that the pigment cells inside them were squeezed very tightly in a very small space, with almost no gaps. Even in one of the fish's bodies, the pigment cells envelop the intestines. They speculated that even if the fish ate glowing prey, it could be dulled by pigmentation around the intestine.
(Photo caption: The most characteristic feature of the Pacific black Arowana is not the slender body, but the extreme black)
Osborn explains: "Arguably, they create a super-efficient, super-thin optical trap where light can't be reflected back or pass through their bodies, and as long as they get into this layer, they can't see it again." "That is, it's a bunch of black bodies wandering in the deep sea.
In fact, this principle of absorbing light is not unique to these deep-sea fish. However, these deep-sea fish have achieved such an amazing light absorption effect based on this principle alone, which is the first time to be discovered, and it is incredible. Biologists have found similar principles in ultra-black animals in the past, but they also need other physiological structures to assist. For example, the ultra-black butterfly or bird of paradise, the principle of light absorption is that the microscopic scale structure locks the photons in the body through a complex arrangement.
If you remember the blackbody you learned in middle school physics, you'll find that the principle of a super black butterfly or bird of paradise is similar to an approximate blackbody with a large box opening, and these deep-sea fish are similar to the ideal blackbody...
(Photo caption: Microstructure of ultra-black butterflies under electron microscopy)
Every time we talk about this camouflage of animals, we can imagine that they have great guiding significance for humans, and we can also learn from their methods to achieve camouflage. This camouflage is not only extremely valuable militarily, but also works in many ways. For some devices that need to absorb light, this technology also has great promise. For example, cameras, astronomical telescopes, solar panels, etc., all have extremely high requirements for the reflectivity of materials, and perhaps some experience can be gained from deep-sea fish in the future.
In short, although human technology has been much more advanced than a hundred years ago, there are still many things we need to learn from animals and nature. At all times, nature always allows us to see its greatness. Therefore, respect for nature is also an indispensable quality in the process of human progress.
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