Scientists Say that Blue Sharks Can Change Color
Scientists at the City University of Hong Kong looked into what makes a blue shark blue, and have discovered that there are tiny nano-structures within a shark’s scales that both reflect blue light, and absorb non-blue colors. The result is that the shark appears blue.
Specifically, scientists discovered that guanine crystals reflect blue light, while melanosomes absorb non-blue light.
Professor Dean of the City University of Hong Kong says that these structures exist within individual cells, which act like pouches. The structures, when packed tightly together within the cell, work together to help the shark blend in with it’s environment.
On BBC News, Professor Dean said, “Very fine scale alterations resulting from something as simple as humidity or water pressure changes could alter body colour, that then shape how the animal camouflages or counter-shades in its natural environment.”
In other words, the blue color also becomes enhanced when a shark swims deeper. As water pressure increases, the guanine crystals and melanosomes are forced closer together, enhancing the sharks’ blue appearance.
In order to make this discovery, researchers needed the help of many powerful microscopes. To find out how the individual components worked, they ran many simulations under different circumstances for each structure to understand them further.
Sources: BBC News