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 ...

Have you ever seen a diving beetle? They’re one of my favorite animals. They live underwater and breathe air from a bubble attached to their butts. I talked about all the ways animals breathe ...

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 ...

Getting enough oxygen in the water can be hard work. While fish and many other aquatic animals take air directly from the water through gills, other animals find ingenious ways to drag air bubbles ...

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 ...

The feather-like structures at the top of this image are the gills of a zebrafish. The tissue below the gills is amphibranchial lymphoid tissue, a newly discovered structure that is enriched with ...