Live Earthworm Lab
Joshua Eisenhart, Bre Ensor, Toby Sponseller, Abby Hoffman
Mrs. Reever
September 27, 2011
October 7, 2011
Purpose: In the lab we will observe the effects of many variables and how they affect
earthworms. We will observe the effects of moisture and light of the earthworms.
Hypothesis: The earthworms will move away from light because it spends so much time
underground where it is dark. The earthworms will also move towards moisture instead of away
from it because it is underground so much of the time and the ground is saturated most of the
time.
Materials:
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Live Earthworms
Dissecting Pan
Hand Lens
Sandpaper
Cellophane
Flashlight
Rubber Band
Petri Dish
Stereomicroscope
Procedure: We started out with picking out a worm and putting it on a wet paper towel. We then
tried multiple types of light of the earthworm and how water affected it. Here are some in depth
steps of what we did.
1. Moisten a paper towel and put it in a dissecting pan.
2. Use setae to locate the worm’s ventral.
3. To determine if the earthworm is sensitive to light. Cover the flashlight with two pieces
of red cellophane. Then dim the room and shine the beam on the earthworm.
4. Do the same steps as step 3 except with 2 pieces of blue cellophane.
5. Remove the cellophane. Shine your light at the worm’s anterior end, then its middle, and
then on its posterior end.
6. Place a wet and dry paper towel in the dissecting pan. Place the worm across the two
towels and see if the worm goes onto the dry or moist.
7. Place a piece of sandpaper next to the dry paper towel and place the worm across the two.
Place the worm with its anterior end of the sandpaper first and then with its anterior end
on the paper towel and record the difference.
8. Add cool water into a petri dish and observe the worm’s heartbeats.
9. Check the worm’s “robin response”. Grab the worm’s anterior end as a robin would and
record the worm’s response.
10. Return your earthworm to the container and dispose of your paper towels. Rinse your
dissecting tray and petri dish out and return your materials.
Data:
Environmental Stimulus
Red Light
Blue Light
White light to anterior end of body
White light to midpoint of body
White light to posterior end of body
Approach/avoidance response to white light
Moist/dry environment
Sandpaper/smooth surface
Heart Rate-Cool Water
Heart Rate-Hot Water
Robin Response
Response
The worm does not move at all
The worm moves away from the light
The worm comes toward the light
The worm moves away from the light
The worm comes toward the light
Avoidance
Moist
Sandpaper
9
10
The worm tries to curl up
Analysis: There were many flaws in this experiment. Every worm is not going to be the same
so the data cannot be tested accurately. Nothing can be proved unless every worm does the
same thing every time, but they are living creatures and will do what they want.
Conclusion: My hypothesis of the earthworm’s response to white light was supported
because the worm crawled away from the light and was not used to the light exposure, hence
why the earthworms live underground. My hypothesis about the earthworm’s response to
moisture was also supported because the worm tried to stay on the moist paper towel. The
experiment went well and went in along with my hypothesis very well.