Deep-sea researchers have captured rare and striking footage of a massive phantom jellyfish drifting through the ocean depths off the coast of Argentina, offering a glimpse into one of the least understood creatures on Earth. The video, recorded during a Schmidt Ocean Institute expedition, shows a Stygiomedusa gigantea—commonly known as the phantom jellyfish—floating gracefully at a depth of approximately 250 meters.

The jellyfish’s enormous size immediately stood out to scientists, with its long, flowing oral arms extending up to 10 meters in length, roughly the size of a school bus. Unlike many jellyfish species, Stygiomedusa gigantea lacks traditional tentacles and instead uses its ribbon-like arms to capture prey as it drifts through the deep sea. Its slow, almost otherworldly movement highlights the alien nature of life far below the ocean’s surface.

This sighting is considered exceptionally rare. Since the species was first identified in 1910, only about 118 documented encounters have been recorded worldwide. Each observation provides valuable data, as much of the phantom jellyfish’s behavior, life cycle, and ecological role remains largely unknown. The footage adds to a small but growing body of evidence helping scientists better understand deep-sea biodiversity.

The encounter also serves as a reminder of how little humanity truly knows about the oceans. According to scientific estimates, roughly 80 percent of the world’s oceans remain unexplored, leaving countless species undiscovered or scarcely documented. Discoveries like this reinforce the importance of deep-sea research missions, which continue to reveal extraordinary life forms hidden in the planet’s most extreme environments.

As exploration technology advances, researchers hope to document more rare species like Stygiomedusa gigantea, expanding knowledge of the deep ocean and its ecosystems. Each new sighting not only fascinates the public but also underscores the vast mysteries still waiting beneath the waves.