An extremely rare look at a barreleye fish with a transparent head was filmed by the Monterey Bay Aquarium Research Institute. They were able to capture an image of one while they were down exploring what they call the oceans twilight zone. Approximately 600 and 800 meters beneath the surface there are a ton of rare and magical looking creatures, with exotic traits and oftentimes bioluminescence.
This fish has a clear head so you can see the inside of the fish. The two markings above its mouth are similar to a human’s nostrils. The eyes are on the inside of the dome with a type of sunglasses effect to protect them, a yellow pigment that is meant to keep their eyes from being burned. Because they are in the deep ocean they are not accustomed to bright lights so they must protect them at all costs. They have extremely sensitive eyes. They hide in the deep and prey on other fish or creatures that have a bioluminescent glow. The pigment in their eyes contribute to their ability to distinguish sunlight from prey. They are pretty small in size measuring at about 15cm-long.
Bruce Robinson who is a deep-sea biologist at the Monterey Bay Aquarium Research Institute said that these advantages help the barreleye to get a clear view of prey trying to erase their shadows. Robinson states that in his 30 years of exploring the deep sea, he’s only seen this fish a handful of times making it quite rare.
“It always puzzled me that their eyes aimed upward, but the field of view did not include their mouths,” says Robison.
They go on to say that this discovery was important to teach them more about this type of fish. Previously all the specimens that were brought to the surface were missing the canopy over their eyes. This one you can see it clear as day, which makes it a special find. Their hypothesis is that the canopy protects their eyes as they steal food from creatures who have stinging tentacles.
Robinson said that their stomach contents include siphonophores’ tentacles as well as prey that siphonophores feed on. Siphonophores are likened to drift nets in the sea with tentacles that will sting and paralyze their prey.