Homeosatsis in Fish

TITLE: Homeostasis in Fish

INTRODUCTION: Homeostasis is the ability of an organism to maintain an inner equilibrium or balance. Fish, as well as other higher level organisms, possess this ability. When the environment around a fish changes the organism does a variety of thing to maintain balance. One such occurrence is when a fish opens its mouth more or less with a change in temperature.

OBJECTIVE: The purpose of this lab was to observe the rate of diffusion of H2O at different temperatures.

HYPOTHESIS: I believe that the fish will open itЎЇs mouth increasingly more as the water becomes colder to maintain homeostasis.

MATERIALS:

ÐŽ© Distilled H2O (30ўЄ C)

ÐŽ© Goldfish

ÐŽ© 1000 mL beaker

ÐŽ© Thermometer

ÐŽ© Ice

ÐŽ© Stirring rod

ÐŽ© Graph Paper

ÐŽ© Masking Tape

PROCEDURE:

1) Place goldfish in beaker with enough water for it to move around.

2) Take the temperature of the water. Add ice or warm water until the temperature is approximately 30ўЄC.

3) Allow the fish to adjust to the temperature change.

4) Count the number of times the fish opens its mouth in two minutes. Then, divide this number by two to get the per minute breathing rate. Record your results.

5) Put ice in the beaker until the temperature has lowered to 25ўЄC. Then repeat steps 3 and 4.

6) Lower temperature 5ўЄC at a time and repeat steps 3 and 4 each time.

7) Continue lowering the temperature until it is about 0ўЄC.

8) As the water level rises dump out some of the water to kep it at a constant level.

9) Once you have finished the experiment slowly add warm water until the water has returned to its original temperature.