By Line: Purvi Jain
For fish inhabiting the immense darkness of deep-sea, ultra-black provides great camouflage in the fish-eat-fish world. Scientists who are studying a few of these exotic creatures now have unraveled secret which is behind their extreme color.
These fish-like fang tooth, the Pacific Black dragon, the anglerfish, and the black swallower have modified shape, size, and packaging the pigment inside their skins to the point that is reflected in less than 0.5% of the light that hits it, said researchers on Thursday.
They have studies 16 such species that fit into the definition of ultra-black. These spanned six different orders of fishes – large groups that have the same evolutionary history- indicating this modification which has evolved independently in all of them.
“In the deep, open ocean, there is nowhere to hide and a lot of hungry predators”, says zoologist Karen Osborn of Smithsonian institution national museum of natural history in Washington who is the co-author of research which was published in the journal current biology. “An animal’s only option is to blend in with the background”.
Very little sunlight penetrates more than 650 feet beneath the ocean’s surface. Some of such fish resides three miles deep.
At such depths, bioluminescence where light emission by living organisms is the only light source. Few of ultra-black fish consists of bioluminescence lures on their bodies to coax prey too close to be eaten easily.
The skin of these fish is amongst the blackest material ever known which absorbs light so efficiently that even in bright light they appear to be silhouettes, as Osborn discovered when they tried to photograph them after they brought up at the surface.
The pigment Melanie is abundant in this ski and is effected by unusual fashion. By perfect packaging sized and shaped melanosomes pigment filled structure within the skin cells to tightly packed and continuous layers at the skin’s surface. The fish itself ensures this layer of skin gets light and never gets skipped.
“This mechanism of making thin and flexible ultra-black material”, says Osborn, “could be used to create ultra-black materials for high tech optics or for camouflage material for night ops”.