When you and I take a deep breath, we pull air into our lungs. That’s because humans are mammals. But fish aren’t mammals. They usually don’t breathe air. They usually don’t have lungs. That’s what I ...

When we say that someone is a “fish out of water,” we sometimes mean to suggest that they are uncomfortable or out of their ...

Fish live surrounded by water, so the idea that they might struggle to breathe sounds wrong at first. It feels like asking whether birds can fall out of the sky. Still, the question keeps coming up, ...