Are Sharks Color Blind?
Sharks in general have the ability to smell blood from a very large distance away, but unfortunately, they cannot see the color red.
To decode retinal vision, vertebrates have evolved a highly versatile set of opsin genes that produce light-sensitive pigments. A rod opsin helps with vision in low light, and four kinds of cone opsins help with vision in high light and the detection of colors throughout the visible light spectrum.
Researchers from the University of Western Australia examined the visual systems of numerous species of elasmobranch (sharks and rays), and their findings were published in Biology Letters. They discovered that the diversity of eye design reflects the ecological and behavioral diversity of the taxon (a population of organisms).
Sharks were formerly believed to have relatively weak vision, according to a theory that was partly based on the nighttime environments of the few representative species included in the initial research.
The scientists examined the retinal cells of 17 species of sharks captured off Queensland and Western Australia using a method called micro-spectrophotometry.
Based on the research it has been found that the majority of the species have a similar kind of light receptors, called rod cells, they are very sensitive to light and enable night vision but are unable to differentiate colors.
According to a study, which is the first to look into the genetic basis and spectral tuning of the shark visual system, the toothy predators are probably forever seeing the world in black and white.
Both sharks and people may be saved as a result of the advantages.
Based on findings discovered by Dr. Nathan Scott Hart from the University of Western Australia, Sharks are color blind, all because of the photoreceptors in their eyes. To enable animals to see, there are two primary categories of light-sensitive cells: Cone cells of various kinds help differentiate colors, while rod cells aid in measuring brightness.
They took a closer look at the retinal rod and cone photoreceptor cell architecture of sharks. Sharks appear to only have one type of cone, but human eyes have red, green, and blue cone varieties.
According to Hart, their research implies that “contrast against the background, rather than color per se, would be more essential for item identification by sharks.”
Shark relatives like rays and chimeras do not have color blindness.
The research conducted by Hart and his team is available online in the journal Naturwissenschaften from Springer. This could help to stop attacks on people and aid in the creation of fishing equipment that could lessen shark bycatch in long-line fisheries.
According to the team’s research, all cartilaginous fish have lost the SWS1 and SWS2 opsin genes, just as marine mammals.
All shark species that have been researched so far appear to be cone monochromats, and this has been confirmed, but various species may have single cone opsins that belong to the LWS or for the RH2 opsins.
In Western Australia, the community, the media, and the local government are all debating how to live in harmony with these intriguing and complicated animals. Following deadly shark attacks, there are frequent requests for either targeted or general shark culling.
