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

As a fish swims through water, the dorsal fin stabilizes it and keeps it from rolling over. But over time, many fish have evolved different uses and appearances for these skin flaps.

The white belly of a great white shark serves a surprisingly useful purpose.

These tiny deep-water fish grow only about 4-inches long, and they don't swim. They "walk" about 130-feet down looking for ...

Mesmerizing, kaleidoscopic, and fabulously exotic, the huge variety of types of saltwater fish to pick for your aquarium will ...

Next, place the knife on the fish’s back just behind the dorsal fin, and make a cut downward at a 45-degree angle toward the head. Cut until your knife hits the backbone, but do not sever the ...

The fish was “slender” and “fusiform,” and it had an adipose fin, a fleshy dorsal fin without bony rays that is common in fish like salmon, according to the study.