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


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.


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).


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.


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
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