Amazon's Monster Fish Fast Disappearing

The Amazon's largest fish is nearing extinction, reports LiveScience, though it's not because its habitat has drastically changed. The arapaima, or pirarucu, is huge for a freshwater fish, weighing upward of 400 pounds and reaching 9 feet in length. Unfortunately this makes the Amazonian giants easy targets for fisherman—along with their tendency to hang out near the water's surface so they can, yes, breathe air. (They are the only known fish in the world whose gills allow them to breathe underwater but whose primitive lungs allow them to also breathe air. And they've got another quirk: The males actually incubate tens of thousands of eggs in their mouths, guarding them with everything they've got.)

The arapaima is being overfished by some groups in the Amazon not only for their flesh and tongues, but also to make jewelry out of their large scales, reports National Geographic. Interviewing 81 local communities, researchers found that the fish appear to be extinct in about one-fifth of them already, and are depleted or nearing extinction in more than half. The good news is that communities that have established fishing rules have 100-fold the number of arapaimas, a sign that regulation could help revive the dwindling numbers. (Check out which bird is back from the brink of extinction.)