It’s the longest migration of any freshwater fish in the world, according to new research—and that creates a host of dangers for this unusual animal. The dorado (pictured, a juvenile from Brazil) is ...

In the rainforest north of Rio de Janeiro, a new species was discovered in a small stream. Raphael Nogueira via Unsplash In the vast network of streams and trees and mountainous forest that make up ...

A global assessment on migratory freshwater fish species, published in March, found that there are 325 species of migratory ...