A team of explorers rappelled into the shaft-like cave and found a “pinkish” animal living in a cold river of the “deep dark zone.” Take a look.

Its transparent head allows it to look upward ... Living in depths between 2,297 and 9,006 feet, this deep-sea fish is mostly known for being able to swallow up 10 times its size in food.

To move, this species uses two fins—one pectoral and one dorsal—that are so thin they are almost transparent. As with sea horses, sea dragon males are responsible for childbearing. But instead ...

Weedy sea dragons have very long, thin snouts; slender trunks covered in bony rings; and thin tails which, unlike their seahorse cousins, cannot be used for gripping. They have small, transparent ...

Evolving roughly 27 different times in the long history of fish, bioluminescence—the biological production of light—is one of ...