Daphnia Magna Experiment

In the present study, the influence of temperature on the heartbeat rate of Daphnia magna was studied using variations of temperature. To determine whether the Daphnia species heartbeat rate is influenced by temperature, the effects of three different temperatures (±5oC, ±16oC, ±34oC) was investigated. Daphnia magna is a crustacean, that lives in aquatic environments.
Predictions were based on the knowledge that physiological processes increase at higher temperatures, therefore, it was hypothesized that the Daphnia's heart rate will be faster at higher temperatures and slower at low temperatures. Overall, a Daphnia's heart rate was proven to be dependent on temperature.

Introduction

Daphnia magna is a small aquatic crustacean, also known …show more content…
The Daphnia was then put on a special microscope slide with a depression, which was prepared with a small smear of Vaseline. A drop of the control water was added in the depression and a cover slip was put over the depression slide. It is helpful to keep the drop of water small, so that the Daphnia cannot swim out of one’s field of view. In addition, it is important to write down the temperature of the water added in the depression into one’s table of data.

The slide was then placed under the microscope to focus on the Daphnia’s beating heart, which lies on its back. The Daphnia was observed under the microscope with a 10x magnification. The number of heartbeats that occur in 30 seconds were counted with the assistance of a lab partner, as one times 30 seconds and one counts the heartbeats. The number of heartbeats in a minute were recorded in the data table, by multiplying the number obtained in 30 seconds by two to get the number of beats per minute. The process was repeated for water temperatures of cold water, ±5oC and warm, ±34oC . Each time the water in the depression was removed with the pipette and replaced by the different water temperature. The experiment was repeated with two more individual Daphnia’s and soon after the experiment they were rinsed into the used container. Thereafter, the average of the three readings was

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