Looking at Fish
Fish live their entire lives under water. Fish are vertebrates (ver-ta-brits), meaning they have a backbone, and are cold-blooded. Most fish are covered in scales, which are like lots of tiny pieces of armor that overlap and protect the fish. Most fish also have fins, that let them move through the water much more easily than humans are able to. Fish also lay eggs to reproduce. Not all fish have scales or fins, such as seahorses.
Some fish live by themselves while others live in large groups together. These large groups of fish are called "schools," and are useful for survival because they confuse larger fish and make the smaller fish much harder to catch and eat. Fish are found all over the world, from the mountains to parts of the ocean so deep that sunlight doesn't even reach it.
