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 ...

Fish can drown. While it may not seem like it, fish do require oxygen to breathe; it’s just that they get what they need from the oxygen dissolved in water rather than in the air. Too little oxygen ...

Fish can suffocate and die from oxygen deprivation, even when surrounded by water. This occurs when dissolved oxygen levels are too low due to pollution, heat, or other environmental factors, or if ...

So if water is composed of oxygen, and fish need oxygen, what the heck is deoxygenated water? Do fish only use free oxygen molecules not tied to their hydrogen counterparts? And if so, how does the ...

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

Most people assume that fish are perfectly safe underwater and that drowning is impossible for them. After all, they are uniquely designed for life beneath the surface. But the idea that fish cannot ...

Fish can drown. While it may not seem like it, fish do require oxygen to breathe; it's just that they get what they need from the oxygen dissolved in water rather than in the air. Too little oxygen ...