If you came face to face with a pacu, what would you do? Never fear—the pacu may look like a big and scary fish, but it's actually quite harmless. Pacu live in the freshwater rivers that run through the subtropical Pantanal region in South America. Pacu have strong teeth that they use to munch on the seeds and nuts that fall into the water from trees along the river.

Image credits: main image, © Ariel Rotondo/CC BY-NC.