Measuring Snail Speed
Materials:
50 ml graduated cylinder
Clear container (large enough to submerge the cylinder on its side underwater)
Enough seawater to fill clear container (above) to a level just above the cylinder when cylinder is on its side.
Metric ruler
Stopwatch or other timing device
Live mud snail
Suitable food for mud snail
Procedure:
1. In a group of 2 – 3 students, assign each person in the group a job. Your group should have a Recorder,
a Materials Manager, and a Timer (Materials manager and Timer jobs may be performed by the same
person if doing this lab in pairs).
2. Read through each step of the procedures below. Form a hypothesis related to the effect of food on the
speed of the snail. Write your hypothesis on your student handout.
3. Below your hypothesis, complete the pre-lab practice table. Use the formula for speed given above the
table to calculate the speed for each trial. Calculate the average distance, time, and speed for the six
trials performed.
4. In the results section of your handout, draw 2 data tables like the one in the pre-lab activity to record
your data. Title one table “Snail Without Food” and the other “Snail With Food.” Make sure you
include rows for totals and averages for each column.
5. Obtain materials, measure the length of the graduated cylinder, and practice using the stopwatch.
6. Fill the clear container half full with seawater.
7. Obtain a snail and carefully place it in the bottom of the graduated cylinder (the water should break its
fall, but angle the cylinder so as to not drop the snail too quickly. If you mishandle the snail, it may not
perform/move as well as it would if you are gentle!).
8. Place the graduated cylinder in the clear container and lay it on its side. Water should cover the
graduated cylinder.
9. Begin timing the snail when it starts to move toward the opening of the graduated cylinder.
10. Continue to time the snail until it stops moving, or reaches the end of the graduated cylinder. Three
minutes is the maximum for timing the snail.
11. Record the time in seconds on the first table that you have created.
12. Use the ruler to measure the distance the snail traveled in millimeters (mm) and record on the table.
13. Return the snail to the bottom of the cylinder and repeat steps 8 – 12 at least 3 times (more if time will
allow).
14. Place some snail food in the opening of the graduated cylinder.
15. Repeat steps 8 – 12. Record your data in the 2nd table that you have created.
16. Clean up your area and return all materials. Return water and snails to the area designated by your
teacher.
17. Compute the average time and distance each snail traveled and record on your tables. Calculate and
record the speed for each trial by using the formula for speed used in the pre-lab practice table.
18. Complete each table by computing the average speed of the snails.
19. Place your group’s results (average speed from each set-up) on the board.
20. Complete the Analysis and Conclusions questions on your student handout.
Student Handout:
Measuring Snail Speed
Hypothesis:
______________________________________________________________________
____________________________________________________________________________________
Pre-lab:
Complete the following data table by calculating the totals of each column then the averages of each
column. Use the formula
Speed = Distance / Time
Trial
1
2
3
4
5
6
Total
Average
Results:
Distance (mm)
70
68
65
71
52
60
Time (seconds)
130
125
180
140
128
155
Speed (S= D/T)
(draw, title, and complete your two data tables below)
Analysis and Conclusions:
1. What is the variable in this experiment?
2. What is the control group in this experiment?
3. What is the experimental group?
4. What is the independent variable?
5. What is the dependent variable?
6. What it the range of your group’s results for the speed of the snail, for
a) the control group?
b) the experimental group?
7. Do you think that the variable had an affect on the speed of the snail?
Explain your answer.
8. What is the equation used to calculate the speed of the snail?
9. What units are we using when we refer to the speed of the snail (example: units for the speed of a car
are miles per hour or miles/hour)?
10. Observe the class results on the board. Why do you think different student groups doing this experiment
may show different average speeds for their snails?
11. Why is it preferable to run 3 or more trials rather than just one trial in this type of experiment?
12. Why do you think it’s preferable for several groups of student scientists to perform this experiment and
to compare results?
13. The snail is a rather slow moving animal. Name one adaptive feature that helps the snail compensate for
its slowness.
14. Describe an experiment that would prove or disprove the following hypothesis:
Hypothesis: Snails will travel faster vertically than horizontally
Procedure: