From the Spring 2010 Conservationist for Kids
By Joelle Ernst and Greg Kozlowski
Fins help fish move through the water. The caudal (tail) fin pushes the fish forward, while the other fins are used for steering and balance, to allow the fish to stay in one place, and to dive or rise to the surface.
Gills and Gill Covers
Fish get their oxygen directly from the water. Water enters the mouth and then passes over the gills, where the oxygen is removed. Gill covers protect the gills from injury. Without gills, the fish would not live.
Scales cover the fish's body and help to protect it from injury and disease.
The lateral line runs along the length of a fish's body. It is made up of specialized cells and can sense vibrations caused by nearby fish and other aquatic animals. The lateral line helps fish to locate food (prey) and swim close together in schools without bumping into one another.
Aquatic Food Chain
A food chain shows the links between what an animal eats and what it is eaten by. This sample food chain might happen in a pond, lake or stream. Follow the arrows up the line to the "top predator."
Fish eat a variety of things. Large predators such as largemouth bass and chain pickerel eat other fish, as well as frogs, snakes, mice and even birds. Bluegills and pumpkinseeds eat insects and zooplankton-tiny underwater animals. The types and sizes of food that fish eat usually changes as they grow. Some fish, such as trout and sunfish, eat mostly insects and zooplankton their whole lives.