When a fish opens its mouth, the flap closes, drawing water into the mouth. As the fish closes its mouth, the flap opens. Oxygen is extracted from the water as it passes over the gills.

In tadpoles, both human ear and fish gill enhancers showed activity in their gills. In lizards, a related program was active ...

The fish's blood pH initially fell by 1.2 units, but after just a few hours their gills were able to correct this by bringing in bicarbonate ions from the surrounding water.

Freshwater fish take up chemicals from the surrounding water through their gills Biologists have cast doubt on the long-held theory that fish gills evolved primarily for the purpose of breathing. The ...

Image of the eel escaping from the fish's gills. Videos using X-rays have discovered exactly how the eels do this. ... The photographs and drawings (B—E) show X-ray images (left) ...

Scientists believe human limbs evolved from the gills of sharks - thanks to a gene named after Sonic the Hedgehog. The discovery comes from analysis of skate, a cartilaginous fish which has much ...

Humans' outer ears may have evolved from the gills of prehistoric fish, a new study finds. Gene-editing experiments indicate ...

Some teenage Japanese eels have found a way to avoid becoming a fish’s next meal. Anguilla japonica eels can escape a predator’s stomach through the fish’s gills. Now, scientists are using X ...

Known as the Gill Oxygen Limitation (GOL) theory, it has been proposed as the universal mechanism explaining fish size and has been used in some predictions of future global fisheries yields.