In the fascinating underwater world, gender is far from fixed. Many aquatic animals can change their sex, a unique biological process known as sequential hermaphroditism. This natural adaptation ...

The Polish Geological Institute-National Research Institute reports a Lower Devonian (419 to 393 million years ago) fossilized trackway in the Holy Cross Mountains, Poland, attributed to dipnoan fish.

Teleost fish exhibit a remarkable suite of blood‐related adaptations that underpin their ecological success in diverse aquatic environments. Unlike mammalian red cells, teleost erythrocytes retain a ...

3D rendering of the tiktaalik, an extinct walking fish. Dotted Yeti/Shutterstock When you think about human evolution, there’s a good chance you’re imagining chimpanzees exploring ancient forests or ...