Mucus coats and protects the body of a fish. Handling fish removes the mucus and can be harmful to the fish. Fins are used for swimming and sometimes for protection. The position of a fish s mouth gives a hint as to where it feeds in the tank. Fish can smell odors in the water with receptors on their heads.
Fish hear by feeling sound waves travel through their body.
A fish s body coloration or pattern sometimes helps him hide from or confuse predators. The shape of a fish s body tells a lot about the way it lives. Some fish are built for speed and others for hiding on the bottom or between rocks. Bottom dwelling fish usually have whiskers or barbels on their chins to help find food. In cartoons you can see that when fish breathe, air bubbles come out of the mouths of fish.