The silver spider or the little dorien, inhabits a layer of the deep sea, where the blue twilight zone is soaked to black, often half a mile below the surface. From there, they can see the world as no other animal known to science.
Researchers have generally understood that the color vision was not necessary in the deep sea. It is too long for sun rays to penetrate, and so there is no light to provide space for color. But in a study published Thursday in Science, scientists interested in the development of the color vision analyzed the genomes of 101 different fish. They discovered that one, the silver spider mite, has more genes to discriminate against dew light than any other spine on the planet. These genes make it possible to see the full spectrum of remaining daylight and the entire spectrum of bioluminescence in the deep sea. Other fishes may also have this ability to detect color in the deep sea.
Typically, vertebrates have up to four confotoreceptors and a rod photoreceptor. For example, most people see color entrance from three cones – red, green and blue. Cones helps us see colors in bright light, but in low light we are usually color-blind and see only intensity from the entrance of a single rod.
But some deep sea fish seem to see their world in a completely different way.
Zuzana Musilová, an evolutionary biologist at the Charles University in Prague who led the study and her law first noticed that these fish had lost the genes of other fish had to make germs and openings that could detect red and ultraviolet parts of the spectrum. This was not surprising: these wavelengths do not penetrate into the deep sea. But then they found that some deep-sea fish had extra copies of genes to make sticks.
Closer to 101 genomes, they found that three different lines of deep-sea fish had extra copies of genes to see in low light. Among these, the silver spider took the cake. It had genes for two conusopsins and 38 rods of opus – more abundant and sensitive to more blue than any known vertebrate.
“We were pretty, let’s say, surprised to find this because it’s very unique,” says Dr. Musilová.
But more surprising was that silver spinifins still used up to 14 of these root-opsin-generating genes (adults in deeper water expressed more rodent genes than their larvae living in shallower waters). And every opsin is set to a slightly different wavelength of green or blue.
These fishes can use their extragens to discover subtle differences and see the world in shades of blue and green we cannot even imagine.
It’s It is also possible that these fishes should not take advantage of all this extra visual power. Scientists studied earlier mantis shrimps, which have complex eyes with more than a dozen color-receptive cones and a visual processing system like no other animal on the planet. Certainly, they can discover more colors, but further research showed that mantis shrimp is no better than humans in demanding, subtle differences in colors when they have to associate them with sweets.
“The Mantis shrimp is a case study on how wrong we were about how they used all their different receptors,” says Dr. Porter. It is possible that these fish use sticks to see color, but how would that world look? ” is not even willing to make a guess, just because it is as unlike anything we have ever seen, “she added.
Most scientists thought that as creatures moved in and adapted to the deep sea, unnecessary functions, such as vision Specifically, genes used to see color So what is the advantage of copying and holding the rod’s sinus-generating genes
Silverpinifins, which are not bioluminescent, can better detect bioluminescent signals from predators and prey using them in depth Their vision can also help them look better because they migrate between different depths of development.
“Either there is some difference ecologically that drives this or have we not just looked at enough things to see the same pattern in other marine species? “Doctor said,” there’s still a lot we don’t know about the deep sea. “