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 ...

Forbes contributors publish independent expert analyses and insights. I write about biodiversity and the hidden quirks of the natural world. ‘Lungfish’ would have been a common sight in the Devonian ...

Watching a fish glide through water gives the impression that it moves in a world foreign to ours. But if we need air to live, how do these animals manage to breathe beneath the surface, where our ...

You may think that since sharks have noses, they use them for breathing. However, unlike mammals, they use them only to smell, not to breathe. Sharks are fish, so they do not have lungs, either. So ...