Increase the Heartbeat of the Daphnia

Increase the Heartbeat of the Daphnia

Hypothesis:

What affects the heart rate of Daphnia magna? We believe that if we give coffee to the water flea, then its heartbeat will increase because of the caffeine. Research has shown that caffeine is a stimulant which will increase heart rate. Caffeine has this affects on humans and so, it should have a similar effect on the water flea.

Experimental Procedure:

Step 1: Put one Daphnia on one slide.

Step 2: Monitor the heartbeat of the daphnia for one minute.

Step 3: Record the data.

Step 4: Add one drop of caffeine to the same slide. Let the Daphnia sit for at least ten seconds and then monitor the heartbeat for one minute.

Step 5: Record the data.

Step 6: Repeat the steps 1-5 two more times but with a new daphnia and a clean slide.

Step 7: Clean up the lab.

Data and Observations:

As the we went through the experiment, we recorded that the Daphnia's average heartbeat while in the water was 134 beats per minute. The Daphnia's average heartbeat with the added caffeine was 126 beats per minute.

Heartbeat of the Daphnia

Trial 1 Trial 2 Trial 3 Average

Water

120 beats per minute

162 beats per minute

120 beats per minute

134 beats per minute

Coffee (1 Drop)

108 beats per minute

144 beats per minute

126 beats per minute

126