The Effect of Automobile Exhaust on Hydra in an Environmental Chamber

Donald H. Anderson             Foreman High School
                               3235 N. Leclaire Avenue
                               Chicago, Illinois  60641
                               312 534-3400

Objectives:

1) To study the structure and habitat of the hydra.
2) To determine if morphological and/or behavioral changes occur within the
   animal upon exposure to automobile exhaust.
3) To determine if the hydra may be used as an indicator to detect pollution 
   from automobile exhaust.

Materials:

100 brown hydra (a fresh water Hydrozoan), fresh pond water, 2 environmental 
chambers, mixed crustaceans including daphnia and artemia (for feeding), auto 
exhaust, large tire inner tube with delivery tube to the environmental chamber, 
10 petri dishes, 6 eye droppers or clean micropipettes, hand lens, one binocular 
stereo microscope with zoom lens, clock, one microprojector and prepared slides 
(plain hydra, hydra with spermaries, with ovary, budding and feeding). 

Strategy:

1) Fill four petri dishes to one centimeter in depth with pond water. Label the 
   petri dishes A1, A2, B1 and B2.  Place five hydra in each dish.
2) Examine the hydra in each group, describing their morphology and behavior.
3) Place two petri dishes in each of the two environmental chambers.
4) CHAMBER A is the experimental chamber connected to the source of pollution.
   (The automobile exhaust contained within the inner tube).  
   CHAMBER B is the control containing room atmosphere.
5) Source of auto exhaust: use a small gasoline engine or automobile to produce 
   gases.  Route gases to the inner tube using appropriate attachments and 
   tubing with a two way valve near the inner tube fill valve.  Back pressure 
   from the filled inner tube will propel gases regulated by the two way valve 
   routed to the experimental chamber.         
6) Fill chamber A with automobile exhaust by using appropriate valves and tubing  
   from pollution source (the large inner tube).  Feed gases into the intake 
   valve (located on the bottom of chamber A).  Close the exhaust and intake 
   valves on chamber A after gases have filled it to its entire volume. 
7) Allow the exhaust and intake valve on chamber B (the control chamber) to  
   remain open to allow the room atmosphere to mix freely within the chamber.

Observations:

1) After each of four 24 hour periods, examine both groups of hydra using the
   binocular microscope. 
2) Compare any morphological changes that may have occurred in the hydra in  
   group A, (chamber A) with the hydra from group B (the control chamber B). 
3) Indicate changes by diagrams or descriptions using a data chart.

       |   DAY     |      # OF LIVING | MORPHOLOGICAL | BEHAVIORAL | OTHER     
       |           |          HYDRA   |     CHANGES   |  CHANGES   | CHANGES 
    1  |           |                  |               |            |         
    2  |           |                  |               |            |         
    3  |           |                  |               |            |         
    4  |           |                  |               |            |         

Care of the Hydra
1) Feed the hydra artemia (washed to remove salt) during the observation   
   periods. 
   Observe any changes in feeding habits and record them on the data chart.
   Fresh water crustaceans need not be washed, but the food must be free of dead 
   organisms.  
2) Replace the water in the petri dishes with fresh pond water daily.
3) Place the petri dishes containing hydra back into their correct environmental 
   chamber.
4) Refill chamber A with automobile exhaust.

Repeat the above experimental strategy
Reduce the trial periods to 12 hours over a four day period.  This will result 
in eight readings, one for each 12 hour period.  Modify the existing chart to 
accommodate the additional readings.
Record and Summarize Your Observations

References:

1) Modern Biology and Modern Biology Laboratories   
    Albert Towle 
    Holt, Rinehart and Winston 1989
    Pages 444-449
2) Developmental Biology
    Scott F. Gilbert
    Sinaur Associates, Inc.  1988
    Pages 592-595
3) Journal of Experimental Zoology
    Vol. 132, No. 3, August 1956
    "Growth and Sexual Differentation of Hydra in Mass Culture"
    W. F. Loomis and H. M. Lenhoff
4) Carolina Protozoa and Invertebrates Manual
    Carolina Biological Supply Company  1980
    Order # 45-3904
5) Carolina Biological Supply Co.
    Burlington, N.C.  27215
    Hydra Bioreview Sheet # 4214 1979
    Hydrozoa Anatomy Sheet # 4212 1964
6) Experiments Using the Jewel Environmental Studies Chamber
    David F. Pray
    Jewel Industries, Inc.
    Hubbard 
    1946 Raymond Dr.
    Northbrook, Ill.  60062
FILMS
Audio Materials
Bureau of Visual Education
Chicago Board of Education  1989-1992
1) Stinging Cell Animals: Coelenterates   2) Worlds of Dr. Vishniak
(S) 02568-82                              (U-S) 02703