The Absence of Effects of Caffeine and Nicotine on Daphnia magna Heart Rate

Abstract

            A higher concentration of a stimulant will produce more action potentials in the cardiac cells. In this experiment, we studied the effects of the concentration of two stimulants, caffeine and nicotine, on the heart rate in Daphnia magna. In order to test this, we added four drops of each solution on the Daphnia magnaand allowed them to sit for seven minutes. After the seven minutes, we recorded a fifteen second video in slow motion to accurately measure the heart rate. We performed three trials per solution to correctly test our hypothesis. According to statistical tests, our hypothesis was not supported. There was no significant difference between the Daphnia magnaheart rate with or without stimulants. We expect this approach to interest those curious about the effects of certain drugs or beverages on heart rate.