Nature & Environment

Gargantuan deep-sea jellyfish filmed off the coast of Argentina

By T.K. Randall
January 7, 2026

Image: Underwater Remote-Operated Vehicle (illustrative)
Credit: Mountains in the Sea Research Team; the IFE Crew; and NOAA/OAR/OER. / CC BY 2.0 (adapted) Recorded with the camera of a remote-operated underwater vehicle, this enigmatic invertebrate was spotted around 253 meters (830ft) down in the waters of the Colorado-Rawson submarine canyon wall.

First discovered in 1899, this huge species of jellyfish has only been filmed a few times.

Typically residing at depths so far from the surface that the light cannot reach it, these animals live a solitary existence in near total darkness.

Their tentacles can reach up to 10 meters in length and their body can grow over 3ft wide.The official name for the species is Stygiomedusa gigantea, but they are also known as phantom jellyfish.

One of the largest invertebrate predators thought to exist anywhere in the world, these creatures are believed to hunt by clinging on to undersea structures.

You can check out the footage for yourself below.

ROV pilots filmed this giant phantom jelly, or Stygiomedusa gigantea, at 253 meters during an ROV descent to explore the Colorado-Rawson submarine canyon wall. #ArgentinianDeepSeeps pic.twitter.com/80tq5JYOTz

- Schmidt Ocean (@SchmidtOcean) January 2, 2026

Source: Mail Online

Tags: Jellyfish