Daphnia Magna Lab Report

INTRODUCTION
The purpose of the experiment is to test multiple substances on a Daphnia Magna, which is a small water flea, to see what affect the substances will have on it. Thus, conclusions can be drawn on how the substances would effect a human heart. “The substances that will be used are called chronotropic drugs which affect the heart rate. A positive chronotropic drug will increase the heart rate, while a negative chronotropic drug will decrease the heart rate”. (College, 2014) The five substances used in the experiment were aspirin, alka seltzer, nasal spray, adrenalin, and acetylcholine. It is expected that alka seltzer, aspirin, adrenalin, and nasal spray are positive chronotropics, where acetylcholine is expected to be a negative …show more content…
A depression slide will be used to examine the Daphnia Magna. Use a pipette to retrieve the Daphnia and put it into the depression of the slide. Try to avoid excess water on the slide, this will make it more difficult becaues the Daphnia will be able to swim around. Place the slide under the microspoe and focus it. Find the heart, which is transparent and located posteriorly. After locating the heart, count the heart rate for fifteen seconds and multiply by four. This number will give you the resting heart beats per minute. Next, pick a substance to test on the Daphnia. Place the substance next to the depression of the slide not directly on the Daphnia. Wait fifteen seconds to allow the substance to take affect. Now, calculate the heart rate again in the same manner as mentioned above. After the heart rate has been obtained put the Daphnia in a separate beaker with water as to not kill it. Repeat these steps for all substances, making sure to clean the slide inbetween with a kimwipe. Record the data in a table and calculate the change in heart rate from resting to after the substance was placed on the Daphnia. Finally calculate the percent change that occurred from the resting heart rate to the heart rate after the substance tood affect.” (College,

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