Giant Phantom Jellyfish Sighting: Rare Species Is As Long As A School Bus — Here's What To Know

Scientists with the Schmidt Ocean Institute discovered a rare giant phantom jellyfish during a deep-sea exploration off Argentina’s coast, which was one of 28 new ocean species researchers discovered during the event.

Details on the phantom jellyfish and other species discovered

The non-profit foundation shared the footage of the massive jellyfish, known as Stygiomedusa gigantea or giant phantom jelly, swimming around 820 feet below the ocean’s surface. The rare species has four arms and can grow up to 10 meters long, which is as long as a school bus, according to Fox Weather and Discovered Wildlife.

The sighting occurred during an Argentinian-led expedition that explored the country’s coastline from Buenos Aires to waters off Tierra del Fuego. In addition to the phantom jellyfish, researchers also identified the largest-known Bathelia candida coral reef in the world, along with several other biodiverse reef systems, per Fox News.

Researchers documenting the deep sea near Argentina captured footage of a jellyfish that they say "can grow as long as a school bus." This video shows the rarely seen giant phantom jellyfish at a depth of about 820 feet. Their arms can reach lengths of more than 30 feet long. pic.twitter.com/JV0aoPytXB

— ABC News (@ABC) February 4, 2026

“We were not expecting to see this level of biodiversity in the Argentine deep sea and are so excited to see it teeming with life,” the expedition’s chief scientist, María Emilia Bravo, said in a statement obtained by Discover Wildlife.

She continued, “Seeing all the biodiversity, ecosystem functions, and connectivity unfolding together was incredible. We opened a window into our country’s biodiversity only to find there are so many more windows left to be opened.”

‘We have been privileged to work with outstanding scientists’

Dr. Melisa Fernández Severini of Instituto Argentino de Oceanografía and CONICET explained how studying the samples they discovered could help better understand Argentina’s ecosystems and detect whether they’re at risk or not.

“We collected an unprecedented number of chemical, physical and biological samples that will be used to understand connections in our waters for years to come,” Dr. Melisa Fernández Severini of Instituto Argentino de Oceanografía and CONICET said, per Fox News. “These samples represent a unique opportunity to understand not only how extraordinary these extreme ecosystems are, but also how vulnerable they can be.”

Schmidt Ocean Institute’s executive director, Jyotika Virmani, spoke highly of the researcher’s work during this expedition and said that she looks forward to more interesting finds in future expeditions.

“We have been privileged to work with outstanding scientists across three expeditions in Argentinian waters and look forward to seeing their research continue to unfold, unlocking new understanding and inspiration,” Virmani said, per Discovery Wildlife.