Some of the deep-sea fish species have somehow managed to evolve skin that is blacker-than-black. This prevents them from being eaten and it helps them to sneak around potential prey. Current Biology now contains a study that was published just a week ago regarding the ultra-blackness of 16 species of fish found in the deep sea. According to the study, even more of these species could be found. The only problem is that they are too dark for the researchers to find. Get it? Ok, let’s leave the puns aside and let’s move on.
Other Dark Animals
The discovery of these means that species in the deep-sea are part of a select group of animals that have evolved ultra-black pigmentation. Other examples include some spiders, some butterflies and the well-known birds of paradise from Australia.
These use ultra-blackness as a tool to highlight their very bright colors, while deep-sea fish simply use it so they cannot be seen, according to Alexander Davis, the lead author of the study and a biologist affiliated with the Duke University located in Durham, in the state of North Carolina.
According to Davis, some of these species of fish use the pigment to camouflage themselves from predators that can hunt them, while others use the pigment to conceal themselves from their prey. For the record, a pigment is considered to be ultra-black if it reflects less than 0.5 percent of incoming light.
That is impressive if you consider the fact that regular black paper reflects, on average, 10 percent of incoming light, so it is about 20 times lighter than the ultra-black pigment found in these fish. These fish are actually thought to be the darkest animals on our planet. It would appear that the darkest species reflected 0.044 percent, respectively 0.051 percent of light, according to the researchers.