--- title: "Giant phantom jelly filmed 990 meters under Monterey Bay trails arms up to 33 feet long" url: https://badiyaa.com/giant-phantom-jelly-monterey-bay-mbari/ published: 2026-11-12T04:35:00+00:00 modified: 2026-11-12T04:35:00+00:00 section: Pets & Animals publisher: Badiyaa --- # Giant phantom jelly filmed 990 meters under Monterey Bay trails arms up to 33 feet long The giant phantom jelly, filmed by MBARI 990 meters under Monterey Bay, has a 1-meter bell and arms that can top 33 feet; MBARI has seen it nine times. A crimson jellyfish with a bell more than a meter wide and four mouth arms longer than a city bus drifted into the lights of a robot submarine 990 meters (about 3,200 feet) under Monterey Bay, California. The animal is the giant phantom jelly, *Stygiomedusa gigantea*, and the clip of it is circulating again on Reddit this week, years after it was first filmed. The footage comes from the Monterey Bay Aquarium Research Institute (MBARI), which logged the encounter in November 2021. Its remotely operated vehicle Doc Ricketts was diving with senior scientist Bruce Robison’s team when the pilots saw what the institute describes as “a billowing crimson curtain” in the dark. ## How rare is this sighting? Very. MBARI says its two research ROVs, Ventana and Doc Ricketts, have completed more than 5,800 dives and recorded upward of 27,600 hours of video, yet the institute has met this species only nine times in over three decades of work. Worldwide, scientists have encountered the jelly roughly 100 times since the first specimen was hauled up in 1899, according to MBARI’s 2021 annual report. That first animal sat unrecognized for about 60 years. Researchers did not formally describe it as its own species until 1959, and it remains the only member of its genus. ## Built like a drifting curtain The numbers explain why it looks so unreal on camera: - **Bell:** more than 1 meter (3.3 feet) across, with soft tissue that can stretch several times its resting size. - **Arms:** four ribbon-like oral arms that can pass 10 meters (33 feet) in length. - **Stingers:** none. Instead of tentacles, it is thought to wrap prey such as plankton and small fish in those arms. - **Depth:** recorded from near the surface down to about 6,700 meters (22,000 feet), mostly in the midnight zone. To put the arm length in perspective, a standard American school bus runs about 35 to 40 feet, so a fully grown phantom jelly trails arms close to that length behind a bell roughly the width of a kitchen table. Its red color only shows up under artificial light; in its pitch-black home, red light does not reach, so the animal is effectively invisible to most eyes. ## A fish that lives in the jelly The species is also known for a lodger. On an expedition to the Gulf of California, MBARI’s ROV Tiburon filmed a pelagic brotula, a small deep-sea fish, hovering over a phantom jelly’s bell and slipping in and out of its arms. Open midwater offers almost nowhere to hide, and the institute says many animals there shelter inside gelatinous hosts. That footage helped confirm a suspected partnership between the two species, which researchers Jeffrey Drazen and Bruce Robison described in a 2004 paper. ## Why robots changed the picture For most of the twentieth century, deep-sea biology meant trawl nets. MBARI points out that nets work for tough animals like fish and squid, but jellies are reduced to mush in them. High-definition and now 4K cameras on ROVs let scientists watch animals like this one whole and alive, which is why so much of what is known about the phantom jelly comes from video rather than specimens. The same clip has done well online before. MBARI reported that its short Fresh from the Deep video of the 2021 encounter passed 4.5 million YouTube views and became the institute’s most engaged post on Twitter at the time. Monterey Bay keeps turning up deep-sea oddities. Badiyaa has covered how the [Monterey Bay Aquarium grew out of an old sardine cannery](https://badiyaa.com/monterey-bay-aquarium-cannery-packard-gift-42/), the [volcanic ‘yellow brick road’ found on the seafloor near Hawaii](https://badiyaa.com/yellow-brick-road-seafloor-nootka-seamount/), and the [elusive Omura’s whale tracked by underwater recorders](https://badiyaa.com/omuras-whale-northwest-australia-recordings/). Since 1899, roughly 100 encounters have been logged worldwide, and nine of them belong to MBARI’s cameras. ## Further reading - [Wikipedia: Stygiomedusa](https://en.wikipedia.org/wiki/Stygiomedusa) *Illustrative image. Image: National Marine Sanctuaries, Public domain via Wikimedia Commons* *This article was produced with AI assistance and reviewed by our Editorial Desk. [How we work](https://badiyaa.com/editorial-policy/).*