Fish have gills because these organs are used to extract oxygen from the surrounding water in which a fish lives. Gills are different from lungs because gills generally work unidirectionally: water moves in one direction... More »

Gills work in fish in much the same way as lungs do in mammals, as they help take oxygen into the blood and release carbon dioxide. Fish draw water into their mouths, which then travels past the many tiny blood vessels i... More » Pets & Animals Marine Life Fish

All fish are cold-blooded, have vertebrae, have fins and breathe through gills. Most fish have skeletons made of bone though sharks and rays have skeletons made of cartilage. More »

Fish live in the water and breathe by absorbing oxygen through their gills. Fish are cold-blooded animals, so their internal body temperature is influenced by the environment. Many fish have scales and use their fins to ... More »

Fish use their gills to breathe by extracting oxygen from the surrounding water. The oxygen that fish and other animals with gills use is bonded to hydrogen molecules and is dissolved in the water. Water molecules are co... More »

A fish breathes through its gills, extracting oxygen from the water. Other sea animals, such as whales, breathe oxygen from the air because they are mammals. More »

Squid extract oxygen from the water using gills, just as fish do. These gills are located in the squid's mantle, the soft but muscular cavity behind the squid's head. More »