Materials__________________ Time Keeper ___________________ Recorder_______________
LAB ACTIVITY: HOW DOES TEMPERATURE AFFECT THE RATE OF RESPIRATION IN FISH?
Background: In this laboratory activity we will change the temperature of the water that a fish
is in and determine what impact, if any, this has on the breathing (respiration) rate of the fish.
Counting gill cover movements is a way to calculate respiration rates in fish. Fish breathe by
taking water in through the mouth and forcing it over the gills when the mouth closes. An
oxygen-carbon dioxide exchange occurs. Then the operculum opens to allow the carbon
dioxide-rich water to exit. By counting gill cover movements, students are getting an idea of a
fishes' response to an ecological change. Respiration rates will typically increase as dissolved
oxygen concentration decreases. An increase in water temperature means a decrease in dissolved oxygen
available for the fish to breathe from the water.
Materials:
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Goldfish
Tank Water
Plastic bucket
Medium beaker, 600ml
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Thermometer
Timer or clock
Ice
Hot water
Procedure:
1. Bring all materials to your lab table.
2. Bring the empty beaker to the aquarium containing the goldfish & fill it ~ 2/3 full with aquarium water.
3. Use a thermometer to measure the temperature of the water in your medium beaker (fish bowl.)
4. The starting temperature needs to be 20 °C. If needed, add warm water until the water is 20 °C.
5. Place a 600ml beaker with the fish into the Tupperware bowl
6. Determine baseline data:
A. Take the temperature of the water in the beaker & record on the data table
B. Allow your goldfish some time to calm down (this may take several minutes)
C. Count respirations (by looking at either the opening/closing of the mouth or the opercula) for one
minute & record on the data table on the back of this page.
DO NOT add ice or hot water directly to the goldfish beaker!
7. Determine warm water experimental data:
A. Fill an empty beaker with warm water from the water bath at the front of the room.
B. Place your fish beaker in the plastic bucket & add warm water to the plastic bucket;
this will slowly increase the temperature inside the beaker.
C. Once the temperature inside the fish beaker has increased ~5 degrees Celsius
count respirations for one minute. Record data in the data table.
D. Repeat, making sure to not go above 30°C
8. Determine cold water experimental data:
A. Pour out any water from your Plastic bucket & fill it approximately 1/3 full with tap water.
9. Add 1-2 pieces of ice to slowly into the Plastic bucket to lower the temperature of the water until the
temperature inside the fish beaker has decreased ~5 degrees Celsius from the original temperature
(20°C)
10. Count the number of times your goldfish breathes in one minute. RECORD in the data table.
11. Repeat making sure not to go below 10°C and RECORD in the data table
12. Clean up all materials & place your gold fish in the “rest” tank to recover.
Data:
Figure 1: Observations of fish with in different temperatures
Temperature
Your fish
Fish 2
Average (Your fish + Fish 2 + Fish 3) ÷ 3
Fish 3
20 °C room temp
15 °C cool
10 °C colder
25 °C warm
30 °C warmer
Figure 2: Observations - Line Graph
 Plot separate lines to show the average breathing rate of fish at each of the different temperatures
 Label each line with a different color
 Add a title that includes the dependent and independent variables
Title _________________________________________________________________________________________
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Breaths
Per
Minutes
200
195
190
185
180
175
170
165
160
155
150
145
140
135
130
125
120
115
110
105
100
95
90
85
80
75
70
65
60
55
50
45
40
10
11
12
13
14
15
16
17
18
19
20
21
22
Temperature °C
23
24
25
26
27
28
29
30
Prelab----Answer the following questions before completing the lab procedure:
1. What is the purpose of this lab activity?
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2. Are fish warm-blooded or cold-blooded animals?
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3. Define the term Homeostasis?
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4. How do you think Homeostasis will affect the fish’s respiration?
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5. What do you think will happen as you increase/decrease the temperature of your goldfish’s water?
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6. Restate what you said above as a hypothesis? (If…. Then… Because)
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7. What is the independent variable (the factor that you are controlling)?
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8. What is the dependent variable (the factor that changes with the independent variable’s changes)
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9. What are the variables we have to keep as constants (factors that are the same for everyone)
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10. What is our control group data (normal environment for the fish)?
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ANSWER THE FOLLOWING QUESTIONS AFTER COMPLETING THE LAB PROCEDURE
11. Based on your data what is the relationship between respiration and temperature in fish?
12. Based on the graph data, what do you think is the relationship between fish behavior and temperature?
13. Does the data in the graph support or contradict your hypothesis?
14. What other factors (besides temperature) may have affected the rate?
15. What do you think happens to the activity of fish in cold climates during the winter months?
16. Why do you think cold-blooded animals, like the goldfish, change their breathing rate when the
surrounding temperature changes?
17. How do you think this might explain the results of the experiment?