Cichlids and stingrays can perform simple addition and subtraction in the number range of one to five as shown in a recent study.

It turns out these predators love to grab a nap when there’s nothing going on and some actually sleep with their eyes wide open!

A "massive" new reef measuring 500 meters (about 1,600 feet) has been discovered in Australia's Great Barrier Reef.

Fish are far more likely to communicate with sound than generally thought—and some fish have been doing this for at least 155 million years.

Researchers have found that using lighted nets greatly reduced accidental bycatch of sharks, rays, sea turtles, and unwanted finfish.

Near the Filchner Ice Shelf in the south of the Antarctic Weddell Sea, researchers found the world's largest fish breeding area known.

Researchers reported finding no fewer than 114 species of animals, coexisting in a complex community, on a ship’s ram from a sunk ship.