puffer fish are not like balloons. Because what's normally inside them isn't air. It's water. Elizabeth Brainerd: What they do is they actually take water into their mouths in a big mouthful of ...
You've probably seen pufferfish on TV or at your local aquarium, puffing up like a balloon when they're startled. But there's way more to pufferfish than their signature defense mechanism. They're a ...