Last Wednesday, I received my Daphnia Magna kit and got straight to work. I set up my space in one of the Hunter classrooms to put my Daphnia Magna in. In order to control the light variable, I had fluorescent light turned on 24 hours and placed the tank containing Daphnia Magna under the light. I poured three liters of spring water into the tank, carefully submerged the container that the D. Magna was shipped in and tilted it so that the water flea could swim out into the larger tank. After, I poured another liter of spring water into the tank to fill it up to the brim. As the crustaceans were getting used to their new environment, I poured 1/8 teaspoon of green algae powder that came with the kit as food for the D. Magna. As time passed, the powder gradually submerged to the bottom, allowing the D. Magna to feed on it. That day, I struggled with the microscope, represented by the picture in my previous post, to view the D. Magna's heart beating. However, I simply was not able to focus the lens enough to distinguish the thinly outlined heart crammed next to all the other organs. As a result, I used a microscope that I have always used in my biology class last year since I knew how to handle it better. Soon after, this was what I saw:
Seven times and five time on Thursday and Friday, respectively, I measured the heart beats per minute of ten Daphnia Magna. I recorded each of the heart rates of the ten Daphnia Magna into my notebook. This is an example of what my data table looks like for every time I measure the heart rates of ten Daphnia Magna. As represented by the numbers, the heartbeats/min of the ten Daphnia Magna are more or less in the similar range. Later, I would average the ten data sets for easier comparison with the other averages that I will calculate for the other experiments I conducted at different times of the day. As I looked through the data that I recorded throughout the day over the course of two days, I noticed a subtle but interesting pattern. The overall heart rates of the Daphnia Magna were relatively higher in the morning and nights than in the middle of the day. On average, heart rates in the morning and night would average in the 400s or even 500s whereas those measured in the midday were in the 300s. As I collect more data, I hope to further testify the conclusion that I made from my first set of experiments by observing a similar pattern. My next steps are to conduct experiments following the same procedure except with a new focus. I have yet to decide on what I will compare the trend in the Daphnia Magna's heart rates to, but I hope my discoveries serve to provide a baseline data for the "real" experiment in which I will examine the effect of detergents on the Daphnia Magna. Here is a picture of me looking in to the microscope to count the heart beats. I am holding a timer with my left hand while tapping the table with my right hand to keep track of my counts.
2 Comments
Next Wednesday, I am going to do my first set of experiment on examining the change in Daphnia Magna's heartbeats throughout the day. The purpose of this experiment is to investigate how the water flea's heartbeat changes at different times of the day and to use this data as the basis for my real experiment next semester. To recap, my goal of the project is to examine the acute cardiac effect of Daphnia Magna by incubating it into different diluted solutions of household detergents. For accurate data analysis, I have decided to do some pre experiments to learn about the different factors that could affect the crustacean's heart rates, the first one being different times throughout the day. Earlier this week, my mentor, Mr. Evans, ordered a Daphnia Magna kit containing a tank, Daphnia Magna, and food for the water flea, which is planned to arrive next Wednesday. In the mean time, I set up temperature probes in the STEAM room in the basement of Hunter, in the room right across the STEAM room, and in the two physics classrooms in order to find the best place to do my experiment. The optimum temperature for Daphnia Magna is 21 degrees Celsius or 69 degrees Fahrenheit. So far, the temperatures in the STEAM rooms are 25-26 degrees Celsius and 20-21 degrees Celsius in the physics classrooms. Since my experiment will last a maximum of three days due to the short life span of the Daphnia Magna, I hope I could use a small space in one of the physics classrooms for my experiment. This is a picture of the temperature probe that was left in the STEAM room to measure the room temperature for 3 hours. As shown on the right, the temperature reads 26.5 degrees Celsius, which is too high for the Daphnia Magna to survive in. This is a highly sophisticated microscope that Mr. Calos allowed me to use to look at the Daphnia Magna heart with. The blue camera on the left is a camera that is attached to the scope. I could use it to take pictures of what I see or even take videos. It would be really cool to take videos of the Daphnia Magna's heart beating!
I look forward to starting my experiment this coming Wednesday and learning about the pattern of changes that the Daphnia Magna's heart goes through. |
AuthorHello! My name is Alice Kim, and I am a senior at Emma Willard. I am interested in learning about environmental issues. ArchivesCategories |