Bio122 Fall 2015 (Dr. Paddack)
Activity 2: Ecological Physiology
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Name: _______________________________________
Physiological Ecology: Impact of Temperature on Ectotherms
Fish Experiment
1. Put about 1/2 inch of dechlorinated water (use ONLY water from the carboy next
to the large container of fish) in the smallest bowl. Add 1 fish, bring it back to
your lab bench, and let acclimate 2-3 minutes.
2. Take the temperature of the water by holding the bulb of the thermometer under
the water for 1 minute. Record the temperature in the chart below, noting
whether you are using °F or °C.
3. Watch the fish for a few minutes and try counting the number of times it opens its
gill cover (operculum).
4. Have your partner time you for 10 seconds while you count the beats and record
in the chart on the next page. Do this 2 more times and then switch roles and
have your partner count beats for 3 more ten-second trials while you time.
5. Put crushed ice in the larger bowl making a depression in the middle.
6. Nest the smaller bowl with your fish in it into the larger bowl so that ice is beneath
and around the sides of the fish’s bowl. Let it sit for 10 minutes.
7. Record the new temperature and the fish’s "beats" in a total of 6 intervals as you
did in step 4. Record in the table below.
8. When finished, put your fish in ‘used fish’ bowl and pour the ice & water into the
sink.
Data from fish & temperature experiment:
 Trial 1 (‘Warm’). Water temperature (Note whether °F or °C): ___________
Number of gill-cover beats within each 10-second interval:
Count #1
Count #2
Count #3
Count #4
Count #5
Count #6
 Trial 2 (‘Iced’). Water temperature (Note whether °F or °C): ___________
Number of gill-cover beats within each 10-second interval:
Count #1
Count #2
Count #3
Count #4
Count #5
Count #6
 Make a graph of the data you collected.
 Label the x-axis (horizontal) grids equally spaced with 1-6 indicating the
observation number.
 Label the y-axis (vertical) with the # beats per 10 seconds.
 Use a different color pen or pencil for the two different trials (ambient water &
iced water) and be sure to make a ‘legend’ to tell you which is which.
 Graph your data from each of the two different trials using a filled circle for
each data point. Connect the dots within each experiment (so that there is a
trend line for each of the two colors).
Bio122 Fall 2015 (Dr. Paddack)
Activity 2: Ecological Physiology
Page 2 of 2
 Describe what you see from this graph and what it tells you about the effects of
water temperature on ecotherms such as fish.
 Why do you think the fish reacted in this way?
 List ways in which the influence of temperature have on ectothermic organisms
impacts them during different seasons or in different areas (consider survival,
growth rates, behavior, etc)?