Myrtie Bryan Martha Ruggles
7831 South Prairie Avenue
Chicago IL 60619


This lesson is designed for students in grades two through eight.

1. The objective of this lesson is to teach the interrelationship
between marine life forms.
2. Students will use role playing to demonstrate an understanding of the
issues and diverse opinions people have about sharks.
3. To teach students that sharks use their senses to detect prey.
4. The students will understand that the sharks body parts help it float
and make it more buoyant.
5. To show that sharks can detect blood in concentrations of 1 part per

Materials Needed:

28 clear plastic cups 10 pairs of scissors
4 measuring teaspoons 10 plastic knives
1 16oz. can of tomato juice 1 large container (6"deep)
2 newspapers 1 town meeting notice to
large container of water post in classroom
1 pack of construction paper several staplers
1 roll of masking tape paint and brushes
red crayons or pencils 1 roll of string
10 cucumbers shark information cards
10 large paper clips 10 pieces of string (3"each)
30 plastic lids (drink cups, yogurt, etc.)
1 tape with announcement of shark sighting


Activity 1

1. Explain that as a class they will hold a class meeting to discuss what
should be done about the shark.
2. Read the town meeting notice to the class.
3. Allow the students to choose the group they would like to represent.
4. Explain how the meeting will run.
5. Distribute role cards to the appropriate students.
6. Tell the students to be prepared to comment on other people's

Activity 2

1. Have each group of students cut 20 pieces of string 12" long. Double
loop them to six inches and knot the loose ends.
2. Tell the students to punch a hole in the top of each marine creature
circle, and attach a string.
3 Beginning with the three top consumers, attach the strings to the ends
and middle of a straw.
4. Balance the straw on your finger so the straw hangs horizontally.
5. Tape the string.
6. Attach the seal, fish, and octopus circles to a second straw.
7. Connect the loose string from the top predator level to the straw
with the seal and fish.
8. Find the balance point and attach another string.
9. Continue until all levels have been completed.
10. Attach the sun to the string and hang your mobile.

Activity 3

1. Divide your class into four groups.
2. Give each group of students 7 cups.
3. Label cups with numbers 1 through 7.
4. Have the students carefully measure 18 teaspoons of water in cups 2
through 7.
5. Put 1/4 cup of tomato juice into cup number 1. (This represents blood
from a wounded fish that a shark might smell in the ocean.)
6. Direct the students to take two teaspoons, of the tomato juice from cup
number 1 and put it in number 2. Stir the mixture. Take two teaspoons
from cup number 2 and put in cup number 3. Continue this process until
cup number 7 has been mixed.
7. Have the students draw 7 circles on a blank sheet of paper to match the 7
cups. Number the circles and color them with the red crayons to
correspond to the color in each cup.

Activity 4

1. Give each group of students the shark information cards.
2. Have students draw a shark, including the fins, on a piece of paper.
3. Cut out picture and use it as a pattern to make another shark.
4. Have students paint shark and add gill slits, eyes, teeth, and a mouth.
5. Staple the body shape along the edges. When partly stapled, gently stuff
the body cavity with crumpled newspaper to give it shape.
6. Staple the shark on all sides.

Performance Assessment:

At the conclusion of the Mini-teach, students will be able to answer the
following questions:

1. What senses are involved in detecting and tracking prey?
2. What is the function of the lateral line on a shark?
3. What is the lowest concentration of blood that a shark can detect?
4. What determines whether a shark will accept or reject its prey?
5. Why must all the cups have the same amount of water?
6. What do you observe about the color of water in the cups?
7. Which parts of a shark's body are essential for swimming?


Students will understand that sharks use their senses to track prey. They
will understand that the marine food web includes a myriad of sea creatures
from zooplankton to tuna and sharks.


John S. Knight and James L. Knight Foundation, Search For The Great Sharks,
(The Cincinnati Museum of Natural History, and Graphic Films Corp.,
St. Paul, Minnesota, 1993 ).

Lynn Wilson, Sharks, (Putnam and Grosset Group, New York, 1992).

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