Arapaima (25/30)

This fish is one of the most huge fishes that can grow up to 4.5 meters long. They like to live in very dirty water which doesn’t have much oxygen in it. In fact, to survive, this fish developed a special swim bladder and can gulp air from the surface. Also, they have massive mouths and can catch not only a relatively large fish but even a bird, when cruising on the surface.