Giant Phantom Jellyfish Filmed in Deep Sea — Experts Say It's One of the Rarest Creatures Ever Caught on Camera

On 4 February, scientists operating a deep-sea research vehicle off the coast of Argentina recorded rare footage of the giant phantom jellyfish, a little-seen marine species that inhabits some of the deepest parts of the ocean.

The animal was filmed at a depth of about 820 feet during an expedition using a remotely operated vehicle, providing researchers with an uncommon opportunity to observe a species that is seldom encountered during ocean surveys.

Confirmed observations of the giant phantom jellyfish are extremely limited. The latest sighting has therefore drawn attention to the challenges of deep-sea exploration and the gaps that remain in scientific understanding of ocean ecosystems.

A Rare Deep-Sea Sighting

The jellyfish was captured on video by SuBastian, a remotely operated vehicle deployed during a research mission led by the Schmidt Ocean Institute. The footage shows the animal drifting through near-total darkness, with four long, ribbon-like oral arms trailing behind its bell.

The species, known scientifically as Stygiomedusa gigantea, is among the largest jellyfish recorded. While the bell of an adult can grow to around one metre in diameter, its oral arms, which are used to capture plankton and small fish, may extend several metres in length.

The expedition that recorded the footage also documented extensive coral reef structures and other marine life in the region. Researchers involved in the mission said the findings add to evidence that deep-sea habitats may be more complex and biologically rich than previously assumed.

Why The Species Is Rarely Seen

Stygiomedusa gigantea typically inhabits the mesopelagic and bathypelagic layers of the ocean, environments characterised by low light levels, high pressure and cold temperatures. These conditions limit human access and make routine observation difficult.

Although the species is thought to occur in most major oceans, excluding polar regions, confirmed sightings are scarce. Marine biology records suggest that fewer than 120 documented encounters have been recorded over more than a century of scientific exploration.

Technological advances have improved access to deep-water environments in recent decades, particularly through the use of remotely operated vehicles and submersibles. Even so, encounters with the jellyfish remain uncommon, a pattern researchers attribute to its low population density and wide distribution.

What the Footage Reveals

Recordings of the giant phantom jellyfish provide valuable information about the behaviour and structure of a species that is difficult to study by other means. Observations of its movement and feeding mechanisms help researchers better understand how energy moves through deep-sea food webs.

The footage also contributes to broader efforts to map and assess deep-ocean ecosystems. Many of these environments remain poorly documented, despite their role in global ocean processes and biodiversity.

Wider Scientific Significance

Deep-sea research has gained increasing attention as scientists seek to understand how climate change, pollution and human activity may affect even the most remote marine environments. Data collected during expeditions such as this one help establish baseline knowledge against which future changes can be measured.

While sightings of the giant phantom jellyfish remain rare, each recorded encounter adds to scientific understanding of deep-sea biodiversity. Researchers say continued exploration will be essential to building a clearer picture of how these ecosystems function and how they may respond to environmental pressures in the years ahead.