Fin whales — mammoth creatures stretching up to 85 feet long and weighing 40 to 80 tons — were, until recently, considered rare sights in the waters off New York in the summer months.

The new species has been found in two small isolated waterways in Brazil's Atlantic Forest, according to a study.

The opah, also known as the moonfish, has relatively small red fins decorating its large, round body, which can grow up to 6 feet (1.8 meters) long. These fins, which flap rapidly as the fish ...

While on an expedition to an unexplored river deep in the Amazon, scientists spotted a large and brightly colored creature just beneath a waterfall. It was a new species of fish. Now, researchers ...

To female molly and Limia fish, nothing is hotter than a male with a large dorsal fin. But these fins aren't just decorations to attract females.

Undersea moon The opah, also known as the moonfish, has relatively small red fins decorating its large, round body, which can grow up to 6 feet (1.8 meters) long.

To escape predators beneath the waves, a flying fish can shoot out of the water and glide long distances because its paired pectoral and pelvic fins, longer and more rigid than those of other fish, ...

What are flying fish? There are about 40 species of flying fish, all of which tend to be cigar-shaped with long, wide pectoral fins on either side of their bodies.

Undersea moon The opah, also known as the moonfish, has relatively small red fins decorating its large, round body, which can grow up to 6 feet (1.8 meters) long.

It's no big news that hands and feet evolved from aquatic fins. But when you look at a modern fish, it's hard to imagine just how how fins like theirs evolved into the hands, wrists and fingers ...

Inside the stout fins of a fish that prowled the shallow waters of an estuary in what is now eastern Canada about 380 million years ago, scientists have found what they call the evolutionary ...

To female molly and Limia fish, nothing is hotter than a male with a large dorsal fin. But these fins aren't just decorations to attract females. Males also use them to fight or intimidate rivals ...