Researchers Film Rare Barreleye Fish in 4K

Monterey Bay Aquarium Research Institute captured the transparent-headed fish about 600 meters underwater during an eight-day deep-sea expedition.

Updated on Nov. 7, 2026 in Aquariums

Small translucent-headed deep-sea fish drifting in dark blue ocean water, lit by a single cool beam with faint marine snow suspended around it. — Monterey Bay Aquarium Research Institute researchers filmed a rare barreleye fish in 4K about 600 meters underwater, 90 kilometers off California, during an eight-day deep-sea expedition. AI Illustration. Upload story photo >

Researchers from the Monterey Bay Aquarium Research Institute filmed a barreleye fish in 4K, approximately 600 meters underwater and 90 kilometers offshore. The sighting was the institute's eleventh encounter with the species Macropinna microstoma.

Why it matters

The footage offers a detailed look at an elusive deep-sea species that is rarely observed. The researchers did not collect the fish, and the recordings will support continued study of the animal's body and behavior.

The fish was observed for approximately 20 minutes using the ROV Doc Ricketts' 4K camera, the first 4K barreleye footage from MBARI and the first sighting from the research vessel David Packard. The extraction does not specify what further analysis of the footage will show.

The players

Monterey Bay Aquarium Research Institute

MBARI is a research institute in Monterey Bay, California, that has completed roughly 7,000 ROV dives and recorded more than 41,000 hours of deep-sea video over nearly 40 years.

Schmidt Ocean Institute

Schmidt Ocean Institute is a research organization that conducted an expedition in the mid-Atlantic Ocean alongside MBARI researchers during the summer of 2026.

The details

The fish was spotted as pilots flew the ROV Doc Ricketts back to the surface for recovery during the eight-day Diving Deep for Delicate Drifters expedition. The vehicle's virtual reality camera also produced 3D stereo imagery of the animal.

MBARI's previous sighting of Macropinna occurred in 2021.
Summer 2026: MBARI recorded a binocular fish during an expedition with Schmidt Ocean Institute in the mid-Atlantic Ocean.
November 7, 2026: The barreleye sighting occurred during the Diving Deep for Delicate Drifters expedition.

Season Trajectory

MBARI has built a multi-decade record of deep-sea video through roughly 7,000 ROV dives. This barreleye sighting adds to its collection of Macropinna observations, which have been recorded at intervals since at least 2021.

The footage gives aquarium enthusiasts and educators a rare, high-resolution look at a deep-sea species that is almost never seen. The 3D stereo imagery may also be used in future educational and outreach programs.

The takeaway

Rare deep-sea species are best understood through repeated direct observation rather than collection. The barreleye footage shows how remotely operated vehicles can document elusive animals without disturbing them.