Guardian: Liam White
This fish has the sky in its skin.
The gases in our atmosphere are bigger than the wavelength of blue light (the up and down movement) and so the waves bounce off in all directions and continue bouncing until the entire sky is blue.
The same thing happens when light hits a blue-green chromis.
These fish scatter blue all over the reef and although you can’t see it, when you snorkel near them you are bathed in blue light.