Decrease of heart rate of Daphnia Magna in 0.5%, 0.75%, and 1.5% KCl environments

Abstract

Research on humans and various insects has led to different conclusions regarding the effect elevated blood potassium levels has on heart rate. While reduced growth and increases in mitochondria and ribosomes in new cells are long-term effects of potassium in insects, short term effects have yet to be thoroughly investigated. Daphnia magna, a planktonic crustacean more commonly known as a water flea, was used in this experiment to test the effects of potassium chloride on heart rate in order to gain an understanding of the effects of high potassium environments. As the concentration of KCl increased, the Daphnia heart rate dropped, which resulted in death. As feldspar and mica rock formations contain large amounts of potassium which may be released in weathering and potassium fertilizers have become increasingly common, the results of this study might be useful in aiding scientists and wildlife preservers in maintaining microbial populations in susceptible areas.