Year 10 Science - Daphnia Experiment

Last Monday, our very keen Year 10 biologists investigated the effect of changing the temperature of pond water on the heart rate of Daphnia. A Daphnia is a water flea with a small heart that is easily visible when viewed under a light microscope.

Our wonderful KS4 biologists first used a Pasteur pipette to transfer a single Daphnia to a Petri dish and immediately added pond water at room temperature until the water flea was just covered by it. They then placed the Petri dish on the stage of a microscope and observed it under low power. Next, they used a stopwatch to count the number of heart beats at fixed time intervals. The heartbeat of Daphnia is very rapid, so they had to count the beats by making dots on a piece of paper. They then repeated the experiment using different temperatures of pond water. At the end of the experiment, they returned the Daphnia promptly to the holding tank. This activity was a great way to promote a good ethical attitude towards organisms used for scientific purposes. 

A massive thank you to our Year 12 scientists: Anuyah, Roberto, Fardous, Sana, and Mania for their help, and a special thanks goes to Sophia (Year 12) for taking a video of Daphnia under the microscope!