Monster of the deep: 'Beautiful and horrifying' barreleye fish is filmed in 4K for the first time

Published: 06:00 EDT, 29 October 2026 | Updated: 06:00 EDT, 29 October 2026 A rarely seen barreleye fish has been filmed in 4K for the first time – with viewers calling the unusual creature 'beautiful and horrifying'. During a recent expedition off the coast of Central California, scientists from Monterey Bay Aquarium Research Institute encountered the fish approximately 1,970 feet (600 metres) underwater.The barreleye fish – which has a transparent head – has only ever been seen 11 times before.'Seeing a barreleye fish is a rare treat,' said senior scientist Steven Haddock.'Crew from across the ship joined the science team in the control room, mesmerized by this remarkable animal. 'Deep–sea animals capture the imagination, creating wonder and awe that we hope will inspire stewardship of the largest living space on Earth.' A rarely seen barreleye fish has been filmed in 4K for the first time – with viewers calling the unusual creature 'beautiful and horrifying'During the expedition, around 55 miles (90km) off the coast of California, scientists set off in a remotely operated vehicle (ROV) in search of gelatinous animals like jellyfish, siphonophores, and ctenophores. Just as the ROV was travelling back to the surface at the end of the day, research specialist Shannon Johnson spotted the barreleye fish, and called for the team to stop. 'Stop stop stop stop stop,' Ms Johnson can be heard telling the team, before taking a deep inhale of breath. Barreleye fish – also known as Macropinna microstoma – live in the ocean's twilight zone, which extends between 660 and 3,280ft (200 and 1,000 metres) below the surface. The creature has large fins that provide stability and maneuverability as it keeps its eyes fixed on the waters above, in search of silhouettes of prey. Once a contender has been spotted, the fish's eyes rotate to keep it in sight, with a gelatinous layer forming a shield of protection. 'Macropinna reminds us of the surprising ways that animals have adapted to thrive in the ocean's midwater,' Mr Haddock said. Just as the ROV was travelling back to the surface at the end of the day, research specialist Shannon Johnson spotted the barreleye fish, and called for the team to stop The creature has large fins that provide stability and maneuverability as it keeps its eyes fixed on the waters above, in search of silhouettes of prey'So many of them survive by looking for subtle optical cues, like a shadow passing overhead, and this sets off evolutionary competition, pitting bioluminescent camouflage against increasingly sophisticated visual capabilities.'After spotting the incredibly rare barreleye fish, the team spent 20 minutes observing it, using a high–resolution 4K camera to capture stunning footage of it. Amazingly, in nearly 40 years of ocean exploration – including 7,000 dives – this species has only been seen 11 times before. 'This is our first observation filmed in 4K, and the footage will help researchers better understand how animals see in the dim light of the deep sea,' the team explained. The footage has delighted animal lovers on YouTube, with many taking to the comments. 'I've seen barreleye videos before, but not deepsea like this. WOW. The transparency of deep sea critters always amazes me, intrigues me to look closely and examine it, but also kind of icks me at the same time,' one viewer said. Another wrote: 'absolutely loooove hearing scientists get excited over cool little guys and wish i could've heard the comms for this.'And one added: 'These are so fascinating! They are beautiful and horrifying, just like the ocean.'