ScienceDaily (Oct. 21, 2012) — Silvery fish such as herring, sardine and sprat have evolved special skin that gets around a basic law of physics, according to new research from the University of Bristol published Oct. 21 in Nature Photonics.
Reflective surfaces polarize light, a phenomenon that fishermen or photographers overcome by using polarizing sunglasses or polarizing filters to cut our reflective glare. However, PhD student Tom Jordan and his supervisors Professor Julian Partridge and Dr Nicholas Roberts in Bristol’s School of Biological Sciences found that these silvery fish have overcome this basic law of reflection — an adaptation that may help them evade predators.
Previously, it was thought that the fish’s skin — which contains “multilayer” arrangements of reflective guanine crystals — would fully polarize light when reflected. As the light becomes polarized, there should be a drop in reflectivity. Read more