For over 20 years, researchers have been encountering a mysterious creature lurking kilometers beneath the ocean’s surface. Now, they’ve finally uncovered its secret: it belongs to a previously unknown group of animals,

Scientists at the Monterey Bay Aquarium Research Institute identified an intriguing new deep sea species off of California. It's see-through, can glow, and nabs prey with a large hood. At one point while filming,

Scientists have discovered one of the largest known sea creatures – a coral the size of two football fields – off the Solomon Islands in the South Pacific. The coral is believed to be several centuries old, and is “so colossal that it can be seen from space,” the National Geographic Pristine Seas team behind the discovery said.

It took nearly 25 years for biologists to discover that a swimming and glowing organism in the ocean’s midnight zone was actually a sea slug.

Scientists uncovered the "mystery mollusk," a strange glowing sea creature lurking in the ocean's midnight depths.

A deep-sea dweller that rarely comes to the ocean’s surface washed ashore a beach in Southern California, making it the second one to appear in just a few months. Now, researchers are trying to figure out what brought it.

One of the largest known sea creatures, the size of two football fields and believed to be several centuries old, has been discovered by scientists.

Formerly known as the 'mystery mollusk,' this glow-in-the-dark nudibranch is the first of its kind to be seen living in the ocean's ultra-dark midnight zone.

Advances in technology that enabled the discovery of a new species by California scientists may lead to a better understanding of the ocean’s depths.

"Everyone in the control room let out a loud 'Oooooh!' at the same time. We were all enchanted," a researcher said.