I believe that many people like to eat scallops very much, what roast scallops, garlic vermicelli scallops, spicy fried scallops, etc., think about it to drool. However, the discovery of scallops by scientists will definitely shock you, that is, an ordinary scallop will have more than 200 eyes, and the structure of these eyes is very complicated. When you pry open the scallops and prepare them for delicious meat, will you become uncomfortable knowing the truth?
<h1 class="pgc-h-arrow-right" data-track="5" > about the perception of scallop eyes</h1>
Scallops are a collective term for these molluscs of the bivalvalve order Scallopidae, and there are more than 400 species in the world, of which more than 60 are important marine fishery resources worldwide. There are more than 40 kinds of scallops distributed in China's coastal waters, and the more famous ones are ctenophore scallops, luxury ctenophore scallops, long rib sun and moon scallops, etc. Because scallops are delicious and nutritious, the "dried scallops" made from the drying of its closed muscles are listed as one of the "Eight Treasures".
The eyes of scallops are usually removed during processing because they grow inside the mantle membrane at the edge of the shell, so it is difficult for us to see their eyes when eating. However, if we pry open a live scallop, we can still see a row of small black eyes at the skirt, which is generally about 1 mm in size. The first to study scallop eyes was an Italian doctor 200 years ago, who not only found the arrangement and number of scallop eyes, but also the coverage of these eye angles was very large, reaching about 250 degrees.
100 years ago, some biologists conducted in-depth research on the structure of scallop eyes and found that the eye structure of scallops is similar to that of humans, and also has corneas, lenses and retinas. In the 1960s, a British neuroscientist found that the principle of vision of scallop eyes and human eyes is completely different, not through the lens to concentrate light on the retina, but to rely on the reflection of the concave surface to concentrate light, somewhat similar to the current reflective telescope.
<h1 class="pgc-h-arrow-right" data-track="5" > the mechanism by which scallop eyes can see things</h1>
Through the in-depth analysis of scientists, the following basic mechanisms and main processes about scallop eye vision have been obtained. First, after the light enters the scallop's eye, it converges slightly through the lens structure, and cannot be imaged on the retina at this time. The slightly converged light then penetrates the retina until it reaches the silver membrane layer at the bottom of the eye. In the third step, a silver film layer in the shape of a concave mirror, the light is further concentrated by reflection, thus forming an image above the silver film.
At the same time, scientists also found that the retina of the scallop has two layers, namely the proximal retina near the silver membrane layer, and the distal retina located above the proximal retina, so the route of light after entering the scallop's eye is: pupil, lens, distal retina, proximal retina, silver membrane layer, and then through the reflection of the silver membrane, the light is further focused, in turn penetrates the proximal retina, and finally falls on the distal retina. Then, a scallop has more than 200 eyes, which is equivalent to forming an array of reflective optical telescopes.
So, why does the silver film layer reflect light efficiently? Scientists believe through research that the main component of the silver film layer is a kind of guanine flake crystal, many of which are grouped together by stacking, separated by cytoplasm in the middle, and the guanine crystal is like a tiny single-sided mirror (there is also this substance in the fish scales), thus forming a silver film layer that appears concave mirror-like.
Through the in-depth observation of cryoscanned electron microscopy, scientists also found that the crystals in the silver film layer are arranged in a square, and it is a multi-layer square densely paved structure of 20-30 layers, which is surprisingly consistent with the mirror surface of many large reflective optical astronomical telescopes, and the advantage of this structure is to minimize the loss of light in the reflection process, that is to say, the scallops not only have more eyes, but also see clearly, which is very magical.
<h1 class="pgc-h-arrow-right" data-track="5" > scallop eyes have a very special place</h1>
First, although scallops have so many eyes, they work together seamlessly with each other. Under normal circumstances, if the viewing angle of each eye is 250 degrees, then it is bound to have a great overlap in the visual content of each eye, and what so many eyes see together, if there is no stable adjustment mechanism, will definitely cause dizziness. Fortunately, the retina of the scallop has a dirty ganglion similar to the gray matter of the brain, which can optimize and fuse more than 200 "imaging pictures" to form a final clear object.
Second, the curvature of the retina of the scallop eye can be adjusted autonomously, that is to say, the light convergence conditions can be controlled spontaneously through the surrounding environment and the situation of light, so that the imaging area changes, which is equivalent to automatic zoom, which is completely different from the function of many animal lens zoom.
Third, the light sensitivity of scallop eyes is very strong. Their pupils can not only be enlarged or reduced according to the intensity of light, but also the perception of light intensity is very sensitive, even very weak light can trigger their reaction, the sensitivity to light is almost 3 times that of humans.
The fourth is the most sensitive to blue-green light. Because scallops usually live in deeper waters, the strongest intensity (emissivity) of visible light is blue light and green light, and the reflectivity of the crystal flakes in the scallops' eyes simulated by experiments is also concentrated in blue-green light of about 500 nanometers. Therefore, in the deep water environment, the structure of the eyes of scallops can fully capture and utilize the most radiant light, which provides a solid guarantee for their better survival.
In addition to scallops, in some deep-sea crustaceans, fish and squid, scientists have also found that their eyes have the above reflex imaging mechanism, these levels compared to mammals at a lower level of animals, but have very complex and delicate eyes, and superb neural perception ability, which is undoubtedly in the long process of adapting to the natural environment, given to them "intangible wealth" and "valuable skills", nature in the opening of a door for them at the same time, but also opened a window for them.