Fish Respiration Rates
Location: Outside U.S.
Date: Winter 2011-2012
I conducted an experiment where beta fish were placed in 6 different conditions varying in temperature and oxygen levels: room temperature water with and without air pump, 10F below room temperature with and without air pump and 10F above room temperature with and without air pump. I counted the rate of respiration for four fish and took mean ratings. The temperature of the water affected respiration in the expected direction - decrease in respiration rate for colder water and increased for warmer water. However, the increase in oxygen levels paradoxically led to an increase in respiration rate in all three different temperature conditions. I am unable to interpret this result.
I assume you are measuring respiration rate by watching the gills such water
in the mouth and pump out over the gills.
In that case, One might expect the oxygenated fish respiration rate to be
less than the non-oxygenated fish because oxygen is more readily available
to the oxygenated fish.
The only variable that I see that might account for your observations are
the metabolic differences in the different fishes.
You know, like, maybe one goes to the gym regularly while the other may be a
So, I recommend you swap the fish around, let them get acclimated to their
environment and take your measurements again.
And the more times you do that, the more times your results will converge.
Use a histogram (http://en.wikipedia.org/wiki/Histogram) to analyze your
Good luck, and
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Update: June 2012