Student handout

Interdependence in the Aquarium

For this experiment, three aquariums are set up in airtight one-quart jars:

Aquarium 1. Water and aquatic animals (guppies or snail)
Aquarium 2. Water and an aquatic plant (Elodea or Anacharis)
Aquarium 3. Water, aquatic animals, and a plant

The water temperatures in all three aquariums will be the same about 70 degrees Fahrenheit.


  1. What do you think will happen in each aquarium after several weeks? Write your hypothesis in your journal.
  2. Each day, observe the aquariums and record your observations in your journal. Be sure to write down the water temperature in each aquarium and any other measurable dat you can think of, such as plant growth. Also be sure to note any other less obvious changes in each aquarium, such as the health of the fish and plants, and the condition of the water.
  3. At the end of the experiment, compare your observations with your original hypothesis. Do your results confirm your hypothesis, or would you rewrite your hypothesis to fit what you know now?
  4. Define interdependence in your own words. What examples of interdependence in other environments can you think of?
  5. What additional experiments would you like to do with the three aquariums? What do you think would happen if you changed the amount of light or heat each aquarium received?


Illustration of the three aquariums for the interdependence experiment; Illustration is by Leyla Sezen.

Author: Tugrul Sezen

Curator: Al Globus
If you find any errors on this page contact Al Globus.
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