This story appears in the September 2017 issue of National Geographic magazine. For a creature that’s less than one and a half inches long, the zebrafish (Danio rerio) looms large in biomedical ...

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.

Now, more than 100 labs around the world are using these transparent fish to study cancer pathology and development in real time.

The World's Forgotten Fishes report is a celebration of freshwater fishes – and it’s a call to action too. Rivers, lakes and wetlands are among the most biodiverse places on earth. They cover less ...