This shark can change color — thanks to hidden nano mirrors in its skin

Blue sharks possess a secret hidden in their skin: a sophisticated arrangement of microscopic crystals and pigments that create their brilliant blue appearance — and may allow them to change color. Scientists have discovered that these nanostructures, found inside tooth-like skin scales, act like nature’s version of layered mirrors and light filters. What's more, changes in the spacing of these layers — possibly triggered by environmental factors like water pressure — could enable the sharks to shift their color from blue to green or gold. The discovery not only unravels a biological mystery but hints at a new frontier in bio-inspired materials with applications in sustainable design and camouflage technology.

source https://www.sciencedaily.com/releases/2025/07/250710113154.htm