Scientists at the Monterey Bay Aquarium Research Institute (MBARI) captured a rare fish called the dreamer anglerfish on ultra-high-definition camera for the first time. A chance encounter with her occurred during a recent dive of a deep-sea guided vehicle, which was supposed to study tiny feodarii.
Oceanologists said that dreamer anglers rarely come into view. Over 36 years of deep-sea research, the devices have captured more than 28 thousand hours of video. But this fish was seen only nine times. This time, an anglerfish with the blackest skin in the world, which is called the “cloak of invisibility” because it absorbs all light, was discovered at a depth of 781 meters in the Monterey Canyon.
What is known about this anglerfish and why is it a “dreamer”?
These small predatory fish have adapted to life at extreme depths, where it is especially difficult to find food and mates. The temperature in the “home” of these fish is slightly above zero, sunlight does not reach the surface through the water column, which also creates colossal pressure.
Like other anglerfish, members of the oneirodidae family have a distinctive feature – their dorsal fin hangs directly above the mouth in the form of a “fishing rod” and ends in a bioluminescent bait. Like a flashlight shining in the dark, prey (mostly small crustaceans) comes at it, which the anglerfish immediately grabs with its wide toothed mouth.
According to oceanographers, when they first noticed this “dreamer,” he was just fishing for prey, the bait was pulled out. However, as soon as the device approached, the fish hid its “fishing rod”.
“Dreamers set ambushes, secretly lying in wait for their prey”
“Instead of actively hunting for food, they let it get to them, which is one of the reasons we see them so rarely,” explains MBARI senior scientist Bruce Robison.
Using remote sensing, it was possible to determine that this individual was approximately the size of a grapefruit. Like most deep-sea fish, the females of this species are much larger than the males: they can grow up to 37 centimeters, while the males only grow to 16.5 centimeters.
These fish were first described at the end of the 19th century, at which time they received the name “dreamers.” To ichthyologists of that time, they seemed “too fantastic to be real,” more like something out of dreams (dream – in English, both dream and dream).
What makes dreamers even more exotic is their ultra-black skin, which helps them remain undetected – it absorbs the light from the “flashlight”, and the prey does not see the fish waiting for it right behind the bait.
“In a habitat where even a single photon can give you away to ever-hungry predators and potential prey, super-black skin ensures that any light that hits you is completely absorbed and prevents your location from being identified in the inky black, wide-open expanse of the deep open ocean.”
Recent research by the MBARI team has shown that “dreamers” are the blackest fish on the planet studied to date. And that these anglerfish structured their black pigments in a unique way to achieve this coloration. Scientists have uncovered this powerful mechanism that they say is already inspiring the development of synthetic ultra-black materials for telescopes, camera lenses, protective gear and other technologies.