Countless small shrimplike scuds and clams strain their microscopic plant food from the water. They, too, then become food for small fishes that, in turn, are eaten by large fishes or by wading birds. The major purpose of this activity is for students to learn about freshwater marshes and reinforce their understanding of the concept of a food web. Since this is a simulation, some of the animals have several roles. Make sure that each student understands who eats whom before beginning the game.
Procedure Use the cards below to simulate a freshwater marsh.
Follow the rest of the procedures as outlined in the activity. Crayfish Picks detritus from bottom with one or two claws. You act this out by picking objects from the floor with thumb and fingers of hands acting as claws. You can only walk backwards. Freshwater Clam Filters detritus from water using gills.