Fish

Fish are animals that live in water their whole lives. They breathe using special body parts called gills. Most fish have scales covering their bodies. Fish are found in oceans, rivers, lakes, and ponds all around the world.

How Fish Breathe

Fish breathe by taking water in through their mouths and pushing it over their gills. The gills pull oxygen out of the water. This is different from lungs, which pull oxygen from air. Fish would not be able to breathe on land.

Types of Fish

There are three main types of fish. Bony fish like goldfish and tuna have hard skeletons. Cartilaginous fish like sharks and rays have flexible skeletons made of cartilage. Jawless fish like lampreys have no jaws at all.

Fun Facts

• There are over 34,000 known species of fish, more than all mammals, birds, and reptiles combined.
• The whale shark is the biggest fish in the world and can grow up to 40 feet long.
• Some fish, like the mudskipper, can actually walk on land for short periods.

Did You Know?

Fish have a special sense organ called a lateral line that runs along the side of their body. It helps them feel movements and vibrations in the water!