Teacher Procedure:
1. First you should decide where around the classroom you will hang your mobile. You will need a high point from which to hang it as well as a fair amount of floor space. Also, before you start, write the names of the animals (see procedure #2) to be included in the food pyramid on the board, so the students will have an idea of all the animals at a glance.

2. Tell the students that they will be making a model of a coral reef food pyramid and displaying using a mobile. Each student will write the name of a reef animal (and/or draw a picture, if you like) on both sides of the white paper part of the hanger.

Provide each student with a hanger and assign them one of the following animals:
shark
barracuda
parrotfish
grouper
triggerfish
butterflyfish
damselfish

You will need two hangers with each of the following names on them:
coral/algae
urchin
marine worm

You will need four hangers with the following animal name on them:
zooplankton

You will need six hangers with the following plant name on them:
algae

You will need eight hangers with the following plant name on them:
phytoplankton

3. To begin assembling your mobile, ask the students which animal they believe would be at the top of the food pyramid of the coral reef. By reading the animals on the board, they will probably know that the shark is the largest predator. Ask the student who has the shark to come hang it in the designated spot. Now ask "What would the shark eat?" A shark might eat any number of things, but it would target a bigger fish to get as much out of a meal as possible. Continue in this way until all of the hangers are attached in the appropriate place.

4. Tell the students that your mobile represents a picture of a coral reef food pyramid when everything is healthy and in balance. It is important to emphasize that there is not just one right answer to this "puzzle." Many animals, like sharks, are not picky eaters and will consume almost anything that comes their way. Use the Background page to further explain the pyramid model. Encourage students to think about the interdependence of species. For example, ask: "Is algae important to the survival of sharks? Do sharks eat algae?" No, but it is important to sharks because without algae, urchins would have nothing to eat, which would mean triggerfish would lose a food source. In the end there would be fewer animals for sharks to eat.