Goths know black is cool. Some scary-looking fish swimming the ocean depths know it too. Researchers are unlocking the deep, dark secrets of blacker-than-black fish that have developed special skin characteristics to help them hide from predators that use bioluminescence to hunt.
The team of researchers, including lead author Alexander Davis, a doctoral student in biology at Duke University, published a study on the ultra-black fish in the journal Current Biology (PDF) on Thursday. They identified at least 16 species of deep-sea-dwelling fish with skin that absorbs over 99.5% percent of light. It's the ultimate camouflage for the inky depths of the ocean.
As the names suggest, dragonfish and common fangtooth fish aren't the cuddliest looking critters in the sea. They might appear nightmarish to squeamish humans, but they're of great interest to scientists who are looking at ways to develop new ultra-black materials.
is the most famous of the ultra-black coatings. It was designed for defense and space sector applications, but has also appeared in architecture and art. It's not the only one of its kind. in 2019.
The ocean research team used a spectrometer to measure light reflecting off the skin of fish pulled up from Monterey Bay and the Gulf of Mexico. These denizens of the deep live up to a mile below the ocean surface.
"The darkest species they found, a tiny anglerfish not much longer than a golf tee, soaks up so much light that almost none -- 0.04% -- bounces back to the eye," Duke University said in a release on Thursday.
The scientists discovered differences between black fish and ultra-black fish by focusing on melanosomes, structures within cells that contain the pigment melanin.
"Other cold-blooded animals with normal black skin have tiny pearl-shaped melanosomes, while ultra-black ones are larger, more tic-tac-shaped," Duke noted. The ultra-black structures are also more tightly packed. Computer modeling revealed these melanosomes "have the optimal geometry for swallowing light."
According to study co-author Karen Osborn, "Mimicking this strategy could help engineers develop less expensive, flexible and more durable ultra-black materials for use in optical technology, such as telescopes and cameras, and for camouflage." Osborn is a research zoologist with the Smithsonian National Museum of Natural History.
The fish skin study adds to our understanding of how these unusual animals function in their dark home worlds. A 2019.
The ultra-black fish presented some challenges for the scientists when it came to photos. "It didn't matter how you set up the camera or lighting -- they just sucked up all the light," said Osborn.
Fortunately for your nightmares, Osborn captured startlingly toothy views of an ultra-black deep-sea dragonfish and an Anoplogaster cornuta. Be sure to cue up some Bauhaus music and stare deeply into their milky eyes.