Water: Middle School




Exercise I. Draw Your Own Pfiesteria!
You will need Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more.
The size of Pfiesteria is 5-450 Um (micrometers). Compare that with your ruler: 1 millimeter is 1000 micrometers. If the smallest Pfiesteria were lined up on your ruler, 200 of them would fit in 1 mm!
Step 2. What does Pfiesteria look like and what does it do?Go to Web site 3: "Images of Pfiesteria"[broken]
. This Web site contains a photographic perspective of the organism, as seen through microscopes.
Click on Web site 2: "Life Cycles of Pfiesteria pescicida"[broken]
, for details on how Pfiesteria actually kill fish.
Step 3. Make your own Pfiesteria.
Use the empty box on the Draw Your Own Pfiesteria worksheet below to draw a picture of Pfiesteria in one of its stages. Make sure you identify the stage. In your drawing, identify the features that correspond to the descriptive name of the lifestage, and label key features such as the flagella
For ideas on how to translate a photograph into a drawing, click on Web site 2: "Life Cycles of Pfiesteria pescicida" [broken]]
and enlarge the drawing.
Measure the diameter of the Pfiesteria in your drawing using a ruler. Now compute the scale of your drawing with respect to a 'real' Pfiesteria.
(Hint: If the diameter of your Pfiesteria is 1 mm, then the scale would be 1:200)
Worksheet: Draw Your Own Pfiesteria
Name: _________________________ Date: ________________
Name of Stage: _________________________
Scale of Drawing: _______________________
(Your Picture goes here.) ![]() |
Additional Resources and activities (as time permits):
Investigate the investigators:
Read and print out the news story "Scientists track the 'phantom'" (PDF) (11 pp, 171K) about how Pfiesteria disabled and affected the scientists researching it.