WASHINGTON: It makes sense that these open-water fish would need to hide in the ocean’s fluctuating polarized light, but no one had shown that it actually works. Polarized light is common underwater. Many fish-and sophisticated modern satellites-have the ability to detect variations in such polarized light. They identified the tissue structure that fish evolved to do this, which could be an analog to develop new materials to help hide objects in the water. They were also able to camouflage themselves more efficiently than reef fish and surface skimming fish that do not normally see polarized light. It seems that the fish managed to overcome this obstacle, and after years of evolution and refinement, they came up with this quaint camouflage that offers them and edge when it comes to eluding predators. Of the three, polarization contrast is thought about most efficient for detection on the open ocean.
Knowing that fish can detect this light, Molly Cummings, professor at UT, said in a release, “Given that, we suggested they’ve probably evolved the means to hide in polarized light”. These fish and three others were studied in the open ocean by the University of Texas at Austin researchers, using a custom-built contraption.
Scientists already suspected that silvery fish like the lookdown and the bigeye scad use their skin as camouflage, reflecting light away to be less conspicuous. The fish achieves this by employing a specialized structure in their platelets within the skin cells, which scatter polarized light differently depending on the angle. According to The Washington Post, the study mostly focused on two types of fish, lookdown and the scad, which belongs to the same family as the bluefin trevally, rainbow runner, white ulua, mackerel scad and a collection of jacks: almaco, thick-lipped, threadfin and ambers. The researchers have found the five different species of fish having the ability. For many years, experts assumed this was the main means of camouflage among such fish, but this camouflage approach works well only if the surrounding water appears uniform, as it does to human eyes. Each fish was confined to a platform that also had a mirror. If we can identify that process, then we can improve upon our own camouflage technology for that environment.
