The lungs of humans are protected by a sophisticated defense system. Similarly, fish have a specialized system to protect their gills. This is a close-up view of the gills of a zebrafish and the ...

Gills and mammalian ears bear little resemblance ... did in a tour-de-force comparative genomic study that included a fish, an amphibian, a reptile, a mammal and even a horseshoe crab (Limulus ...

Fish gulp water through their mouths and pump it over their gills, which contain thousands of tiny filaments through which blood flows. The blood absorbs oxygen from the water as it passes over ...