Salmon possess more powers than the ability to swim upstream. Scientists have discovered that salmon, along with with other freshwater fish and amphibians, can supercharge their eyes in order to give them the ability to be able to see red and infrared light.
Researchers already know that salmon, other freshwater fish and amphibians, including frogs, have the ability to shift their vision from terrestrial environments that include lights on the blue-green end of the spectrum to be able to navigate the murky depths of freshwater. These murky waters have lights on the red and infrared end of the spectrum because of the mud, algae and other substances that filer the light from the visual spectrum.
However, what has been puzzling researchers for almost a century is just how they are able to do it.
Now, we are finally getting insight thanks to scientists at the Washington University School of Medicine in St. Louis.
Published in the journal Current Biology, the scientists uncovered that certain marine life have an enzyme called Cyp27c1 that allows them enhance their vision abilities to be able to see longer wavelengths of light.
"We've discovered an enzyme that switches the visual systems of some fish and amphibians and supercharges their ability to see infrared light," said senior author Joseph Corbo, M.D., Ph.D., associate professor of pathology and immunology, said in a press release. "For example, when salmon migrate from the ocean to inland streams, they turn on this enzyme, activating a chemical reaction that shifts the visual system, helping the fish peer more deeply into murky water."
The enzyme is a form of Vitamin A (which is known to aid in good vision), which changes vitamin A1 to vitamin A2 to make this supercharge occur so that they can navigate with ease even when the waters are murky.
The scientists were able to identify the enzyme in a tiny freshwater fish called the zebrafish, and later confirmed that the enzyme is present in bullfrogs as well.
Interestingly enough, humans possess a form of the Cyp27c1 gene as well, although evolution has not allowed us to tap into the night vision ability.
"But just because our eyes don't make vitamin A2 doesn't mean we can't use it," Corbo said.
The enzyme could potentially be used by in an optogenetic device targeted toward the blind.
Photo: U.S. Department of Agriculture | Flickr