Fish are animals that live in water. They live in almost any place 1 there is water. Some are found in lakes, other fish live in the sea. Most fish never 2 water. There are about 21,000 kinds of fish. One kind might not look like another. Some fish are very small. The smallest one is no bigger than a fly. Others are very big. The biggest fish can 3 to 60 feet. One kind of fish looks 4 it has a little horse' s head. It is called a sea horse. It doesn' t swim very well. A sea horse is mostly pushed along by the 5 water. What does it do when it wants to stay in one place? It takes hold of plants with its little tail.