Measuring 10 feet (3 meters) long and weighing in at more than 400 pounds (180 kilograms), it's hard to imagine that the arapaima, the largest fish in the Amazon River basin, could ever go missing.

The armor that a massive Amazonian fish evolved against piranhas could lead to better body armor for soldiers, researchers say. The arapaima (Arapaima gigas) is one of the largest freshwater fish in ...

The arapaima or pirarucu, native to the Amazon. (Jeff Kubina via Wikipedia [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)]) The arapaima or pirarucu ...

Arapaima gigas is a big fish in a bigger river full of piranhas, but that doesn't mean it's an easy meal. The freshwater giant has evolved armor-like scales that can deform, but do not tear or crack, ...