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Researchers film rare deep sea fish with transparent head

A barreleye fish swimming deep in the Pacific ocean
(Image credit: MBARI)

A team from the Monterey Bay Aquarium were filming for an upcoming exhibition when they spotted a rare site: a deep sea critter with a transparent forehead and bizarre upward-facing eyes.

While collecting and combing jellies for the aquarium's planned Into The Deep exhibition, the aquarium team piloting remote operated vehicles (ROVs) from the Monterey Bay Aquarium Research Institute spotted a Macropinna microstoma, also known as the barreleye fish.

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The barreleye fish has some of the more...unusual...adaptations that nature is capable of producing. 

"Two small indentations where eyes might normally appear on a fish are actually the barreleye’s olfactory organs," MBARI says on its site, "and its eyes are two glowing green orbs behind its face that gaze up towards the top of its head."

The weird green-looking eyes are usually looking straight up, which researchers believe results from the fish hovering below the tentacles of siphonophores and stealing their food. The eyes of the barreleye fish aren't fixed up though, they have been observed to shift forward to see the food that the fish is eating. 


Analysis: Earth's oceans have way more aliens than we're ever likely to find in outer space

Earth's surface is overwhelming covered in water, with its deepest trench just over 7,000 feet (about 2,150 meters) deeper than Mount Everest is tall, and the sun's light all but disappears 200 meters beneath the surface.

It is in these darkest reaches that some of the planet's most bizarre and alien lifeforms are found, and the barreleye fish doesn't even roam that far from the surface. It lives between 600 and 800 meters down, but even though this is accessible enough for ROVs to explore, sighting the fish is incredibly rare.

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According to MBARI, its ROVs recorded more than 27,600 hours of video over more than 5,600 deep ocean dives and have encountered M. microstoma only nine times. What lives even deeper in the ocean is likely to be far more alien to us than a fish with a transparent forehead with bizarre bulbous, upward-looking eyes. 

And honestly, if we ever do encounter surface-dwelling intelligent life on another world many light-years away from us, we're likely to have more in common with those aliens than the ones living out their lives in darkness just two kilometers down and just off the coast of California.  

John Loeffler

John (He / Him / His) is TechRadar's Computing Staff Writer and is also a programmer, gamer, activist, and Brooklyn College alum currently living in Brooklyn, NY. Named by the CTA as a CES 2020 Media Trailblazer for his science and technology reporting, John specializes in all areas of computer science, including industry news, hardware reviews, PC gaming, as well as general science writing and the social impact of the tech industry.


You can find him online on Twitter at @thisdotjohn


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