Ultrablack skin shrouds deep sea fishes

Abstract

In the darkest depths of the ocean, bioluminescence can make a creature stand out like a sore thumb—or tasty snack. Now, researchers have discovered that deep sea fishes have evolved a way to blend in using ultrablack skin. Their findings could inspire new synthetic black materials. Karen Osborn, a marine biologist at the Smithsonian National Museum of Natural History, was inspired to investigate the skin of deep sea fishes after having difficulty photographing specimens. “It didn’t matter how I set up the camera,” she says. “All I got were these incredible silhouettes.” After analyzing skin samples from 16 species of deep sea fishes, Osborn’s team found that their skin reflected less than 0.5% of light (Curr. Biol. 2020, DOI: 10.1016/j.cub.2020.06.044). This ultrablack coloration has never been found in aquatic organisms. Other animals such as birds and insects achieve ultrablack coloration by embedding melanin in a matrix of keratin or chitin