Rare Giant Phantom Jellyfish Sighted Off Argentina

Scientists aboard the Schmidt Ocean Institute's research vessel RV Falkor (too) have documented a rare giant phantom jellyfish in the deep waters off Argentina's coast, revealing unexpected biodiversity in one of the world's least explored ocean regions.

The sighting occurred during a multiweek expedition led by Argentine researchers, who traversed the country's continental shelf from Buenos Aires toward Tierra del Fuego. Using the remotely operated vehicle ROV SuBastian, the team filmed the elusive Stygiomedusa gigantea, known as the giant phantom jellyfish, drifting at about 250 meters in the Colorado-Rawson submarine canyon in the South Atlantic Ocean. The creature's bell measures up to 1 meter across, with four ribbon-like arms extending as long as 10 meters. Unlike typical jellyfish, it lacks stinging tentacles and instead uses its arms to capture prey such as plankton and small fish. Juvenile fish were observed swimming near its bell during the encounter. This marks only the 118th documented sighting of the species in more than a century, underscoring its rarity across global oceans, excluding the Arctic.

The jellyfish was one of many highlights from the mission, which...