A recent deep-sea expedition along the country's entire length documented the jellyfish, along with a surprising number of other species

During a dive off Argentina, scientists documented a rare jellyfish discovered a little over a century ago and seldom seen since, as well as the fish that keep it company.

Scientists spotted a rare jellyfish with huge ribbon-like arms deep in the ocean, where dozens of possible new sea species were also discovered.

The ocean is full of surprises, and scientists are still finding creatures that seem almost unreal. From tiny reef animals to bizarre deep-sea species, these discoveries show just how much of the underwater world we’ve yet to explore.

Architeuthis dux, better known as the giant squid, is likely the inspiration for the legendary kraken. The Granger Collection, New York There are few monsters left in the world. As our species has explored and settled the planet, the far-flung areas marked ...