Scientists have observed a strange phenomenon in oceans worldwide: Fish are getting smaller, even in areas unaffected by overfishing. The exact reason is unknown, though researchers have a few ...

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 ...

A collaborative team of scientists recently found that there is no physiological evidence supporting a leading theory -- which involves the surface area of fish gills -- as to why many fish species ...

A widely debated topic in biology and fisheries sciences is the role of oxygen in the growth of fish and other water-breathing animals. According to new research, developmental changes in individual ...

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 ...