Super-reflective fish skin

摘要

Three species of silvery fish seem to have found a way around a law of physics that governs the reflection of light. The skin of the Atlantic herring (Clupea harengus), European sardine (Sardina pilchardus; pictured) and sprat (Spratus spratus) is made up of alternating layers of cytoplasm and highly reflective crystals of guanine - a molecule that is also found in DNA and RNA.