Food Chain

The food chain is a way of showing how energy moves within an ecosystem. Usually a food chain shows who eats who in an environment. Within food chains there are two types of life within an ecosystem: autotrophs and heterotrophs. Autotrophs receive their energy from the Sun, usually from photosynthesis. Heterotrophs receive their energy from consuming autotrophs and other heterotrophs. You've already learned other words for these types of organisms: autotrophs are producers and heterotrophs are consumers (primary or secondary).

Here's an example of a food chain:



In the food chain pictured above the freshwater shrimp eat algae, which get their energy from the Sun. The freshwater shrimp are eaten by a type of fish named Bleak, which are then eaten by Perch. The Perch are then eaten by Northern Pike. Lastly, the osprey eat the Northern Pike.

Food chains are a simple way to show relationships in an ecosystem. However, they don't show how plants and animals in one chain affect another. In order to show all the relationships between different organisms you need a food web. The next page will have an interactive lesson on the food web.