Rare super black fish swim at a depth of nearly 800m

Scientists recorded an ultra-black anglerfish with the ability to absorb at least 99.5% of light in the deep sea off the coast of California.


Super black anglerfish swim in the deep sea off the coast of California, USA. (Video: MBARI)

A team of scientists from the Monterey Bay Aquarium Research Institute (MBARI) discovered an unidentified fish belonging to the genus Oneirodes , order Lophiiformes (Anglerfish or Anglerfish), Live Science reported on November 15. They recorded the animal at a depth of 781 m underwater using a remotely operated vehicle (ROV) in Monterey Canyon, a massive underground canyon stretching more than 470 km off the coast of California, USA.

The team came across this football-sized fish while collecting small, spiny creatures called phaeodarian - which float in the water column and feed on falling organic debris (marine snow). . According to a statement by MBARI, this is the first Oneirodes fish observed in Montere y Alley since 2016.

In the video, marine snow floats around the animal, but viewers can barely see its details except for the outline of its body. The reason is that the fish's skin is so dark that it absorbs a large amount of light and acts as an invisibility cloak, according to Bruce Robinson, senior scientist at MBARI.

Picture 1 of Rare super black fish swim at a depth of nearly 800m
The skin of this fish contains a lot of melanosomes - cells containing melanin pigment.

This fish belongs to the group of "super black" deep sea creatures , absorbing at least 99.5% of incoming light. According to a study in the journal Current Biology in 2020, there are 15 other marine species capable of absorbing such large amounts of light. Research has revealed that their skin contains a lot of melanosomes - cells containing the pigment melanin, which is also the pigment that gives color to human skin. The shape and structure of these cells allows them to absorb most wavelengths of light that hit the skin.

"The ultra-black skin causes all incoming light, including the bright light from the fish's streetlight-like lure, to be completely absorbed. Nothing reflects to reveal the location," co-author explains researcher Karen Osborn, a zoologist at the Smithsonian National Museum of Natural History and MBARI. This allows the Oneirodes fish to hide while lying in wait and use a fluorescent lure that resembles a fishing rod to lure prey.

Their strange camouflage ability also helps them hide from enemies. When the MBARI team discovered the Oneirodes fish , it was using bait. But the animal quickly "turned off" when it realized it was being followed. The team of scientists determined this was a female based on its size. Female Oneirodes fish can be up to 37cm long, while males are only about 1.3cm long.