At Devil's Hole, a deep aquifer-fed pool, a tiny fish has survived for thousands of years. But now, the Devil's Hole pupfish may be in trouble.

Ruins are all that remain of the Cabo Blanco Fishing Club, a legendary resort for wealthy deep-sea fishermen who flocked there over half a century ago.

Do you have special memories of time you've spent at the ocean -- or in it? Have you had a close encounter with marine life? NATURE wants to know about it.

Rick Rosenthal discusses the challenges he faced during the two-year process of making Superfish.

Rick Rosenthal has a face-to-face encounter with a baby sailfish that emerges from the darkness.

(Airs Sunday, August 29) Marine biologist Rick Rosenthal set out to capture on film the biggest, fastest, most dangerous gamefish in the sea -- the ancient creatures known as billfish.

A textile cone hunts other snails. Its proboscis contains a harpoon, loaded with a powerful venom called conotoxin. It paralyzes its prey so it can be sucked from its shell and devoured.

From cushion stars to the red-lipped batfish, explore the undersea creatures of Cocos Island in photos.

(Airs Sunday, August 23) Explore a haven for some of the most extreme underwater predators.

High concentrations of mercury, a neurotoxin that can damage developing brains in fetuses, are found in some kinds of popular fish such as albacore tuna.