The Catsharks are ground sharks that are known to be from one of the largest families of sharks, but a new study revealed that they can glow in a bright green.
On a research published this Monday in the Nature Journal Scientific Report, researchers from the American Museum of Natural History. They have found a way to know how they see each other down in the deep ocean, where when the species travel deeper, their glowing patterns also continue to get clearer.
But how a brown shark could glow green? Catsharks have a special pigment in their skin that absorbs blue light, then they transform it, and later it’s discharged into green color and the entire process is known as biofluorescence.
Glow in the dark Shark-vision?
The “shark-vision” was made to simulate how the shark sees underwater, where, as said before; the deeper they travel underwater the brighter their glow. John Sparks who is a curator at the American Museum of Natural History’s Department of Ichthyology and a co-author of the study, stated that they had already shown that catsharks are brightly fluorescent, and this work takes the research a step further, making the case that biofluorescence makes them easier to see by members of the same species.
To create “shark-vision”, first, the researchers analyzed sharks’ retinas, which are known to be monochromatic on them. Also Using a technique called microspectrophotometry to determine how sharks’ eyes absorb light. Later they found that the sharks had long rods that allow them to see in low light, and one cone so that they can see blue-green pigments, so adding a few filters to an underwater camera, so only the wavelengths that catsharks’ biofluorescence have could be seen
Only biofluorescence animals?
It’s known that sharks aren’t the only marine animals to use biofluorescence. There are over 200 species of shark and fish that has been found to glow in this way, also squids, jellyfishes and many from the deep sea species that use this as a way to get through the darkness of the deep ocean. Makes sense now why only about 1 percent of the whole sea is known while the rest it still unknown.
Source: Nature