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Treasures of the Great Barrier Reef

Classroom Activity

Objective
To classify fish based on different characteristics.

• copy of "Fish Sorting" student handout (PDF or HTML)

1. To study the wide variety of life forms in a natural environment, scientists use a classification system, which helps them to make comparisons within and among different species. To give students practice with this basic skill, use this activity.

2. Photocopy the "Fish Sorting" student handout and distribute a copy to each student. Give each student drawings of nine different fish. Have students cut out the drawings of nine different fish so they have a card for each fish drawing.

3. Challenge them to sort the cards into categories using only one variable, such as the shape of the body or fin, and have the students share their classification systems with the rest of the class.

4. Compare the different variables that were used to sort the piles. Explain that this procedure is the first step in making a key to distinguish among various types of fish. The next step is to sort the piles into two categories. For example, a student might sort by body shape first, and by patterns second, a process that would result in four piles: flat spotted fish, flat nonspotted fish, snake-shaped spotted fish, and snake-shaped nonspotted fish.

5. To expand on the classification activity, have students use their fish cards to sort the fish according to the fish key. As they proceed, they will observe that the process of elimination leads them to a single identification for each fish.

6. Students can start with any fish card. To determine the name of the fish, they must begin with step 1 on the key. They should read the descriptions on the key and compare them to the fish card they have chosen. If they follow all instructions on the key, they will arrive at the name of the fish.

7. Once they have identified a fish, have them choose a new card and go through the key again to determine the name of the second fish. They can do this procedure for all of the fish cards provided.

This activity asks students to use a classification system, which is a basic organizational tool of scientists. Students should realize that this method can be used in many different areas of science and as a means of organizing data for more in-depth research. When they have completed the activity, students should have only one fish in each category. By looking at the fish after they are categorized, someone else should be able to determine easily why a student placed each fish in each category.