3. Black caiman
Go for a swim in one of the slower-flowing sections of the Amazon, and you might come across one of these. Or, more likely, it will come across you. The black caiman is the Amazon’s biggest predator, and it will eat pretty much anything it can catch. It’s said that a mature adult specimen can grow to a length of 20 feet with a weight of 2,400 pounds. On a cheering note, if a black caiman takes you, it will drown you before snacking on you.
4. Bull shark
Usually, a shark is not what you expect to encounter on a river. But the bull shark has been recorded as far as 2,500 miles upriver on the Amazon, penetrating as far inland as northern Bolivia and Peru. At mealtimes, the bull shark enjoys, among other things, birds, dolphins, turtles and other bull sharks. But the bull shark doesn’t turn up its nose at human prey. Some 69 unprovoked attacks by bull sharks on people have been recorded. Yikes!
The candiru, also known as the vampire fish, is living proof that you don’t need to be huge to scare the living daylights out of people. Most species of candiru grow no more than seven inches in length. It’s hard to untangle fact from fiction here, but natives of the Amazonian basin are said to believe that the fish can swim up a man’s penis. If true, this is made doubly horrifying by the fact that the little fish has spikes on its gills with the points facing rearwards.