Bus-Sized Jellyfish Spotted in Argentina's Deep Sea

The control room of a research vessel fell completely silent when a jellyfish the size of a bus appeared on their screens. Scientists exploring the deep waters off Argentina's coast had just encountered one of the ocean's rarest sights.

Dr. María Emilia Bravo of the University of Buenos Aires led the expedition that discovered 28 species completely new to science. But it was the giant phantom jellyfish that left her team speechless.

"There was a mixture of excitement and disbelief," Bravo told The New York Times. The jellyfish's arms stretched longer than a camper van, making it tricky to navigate their underwater robot around it.

Giant phantom jellyfish are incredibly elusive despite their massive size. First collected in 1899, they weren't officially recognized as a species until 60 years later, and they've been spotted fewer than 120 times globally since then.

The Schmidt Ocean Institute's remotely operated vehicle SuBastian also explored the largest known Bathelia candida coral reef in the world. The stony cold-water reef, roughly the size of Vatican City, provides vital habitat for countless fish, crustaceans, octopuses, and newly discovered species.

The team documented Argentina's first deep-water whale fall during the voyage between Buenos Aires and Tierra del Fuego. They found the deep sea teeming with life in ways they never expected.

The Ripple Effect

This expedition marks one of three successful deep-sea voyages the Schmidt Ocean Institute has completed in Argentine waters. In August 2025, their livestream of the Mar del Plata Canyon went viral with over 17.5 million views and revealed 40 new creatures.

Their 100th expedition two months later yielded 30 new species off Uruguay's coast. By Halloween, scientists had published detailed findings on the year's biggest discoveries, including new black corals, iridescent scale worms, sea stars, and a "death ball sponge."

"We opened a window into our country's biodiversity only to find there are so many more windows left to be opened," Bravo said. Her excitement reflects a growing understanding that the ocean holds far more life than we ever imagined.

Dr. Jyotika Virmani, the institute's executive director, noted that the ocean contains 98% of the living space on our planet. Every deep-sea expedition reveals just how full of life those depths truly are.

The discoveries continue to unlock new understanding about what thrives in the watery world below.