Many fish are very good at camouflaging
themselves, but silvery fish like sardines and Atlantic herring are geniuses at
it. Research shows that those fish use their skin to stay invisible to any predator
from almost all angles
When you reflect light on many different
surfaces, all the other light which is reflected becomes polarized, for that reason
fishermen have polarized glasses. The skin of the fish has irregular layers of
cytoplasm, and also two types of guanine crystals, which refract light. The 2
types of crystals have “different refractive indexes” which can make an unusual
reflective property.
“What these fish do is get around a
fundamental law of reflection,” said Nicholas Roberts, he is a biologist at the University
of Bristol and one of the many authors of the studies.
“The polarization happens over a
range of angles instead of one, and the end product of having all the layers
together is that it creates a polarization-neutral reflector,” said Dr. Roberts
Over a longer period of time those
fish have created a ration of the 2 types of crystals, which leads to having
almost constant reflectivity which hides them from almost every angle. This method can be seen a lot on
silvery, grayish fish.
I think that this is amazing. I never knew fish could camouflage like this. Its awesome and smart. I would really like to see this happen in real life, to see how it works. Also from now one I will defiantly keep an eye on for fishermen and their polarized glasses.
October 24, 2012
