The Effects of Salinity on the Reproductive Systems of Daphnia pulex

1. The Effects of Salinity on the Reproductive Systems of Daphnia pulex Dana Wisseman, Tim Moss, Kari Lysne

2. Question and Hypothesis • The purpose of this study is to determine how the salinity of water affects freshwater invertebrates such as Daphnia pulex. • The hypothesis is that the invertebrates will thrive at low freshwater salinities such as the range of 1-2 ppt. As the salinity of the water increases, the reproductive systems will reproduce less.

3. Background/Importance • Daphnia pulex is a common water flea, a major food source to many animals, and an indicator species. • Fluctuating salinities lead to higher mortality rates and stressed reproductive systems among aquatic organisms. http://www.caudata.org/daphnia/images/Daphnia_magna_large.jpg

4. Methods • Care For Daphnia pulex: The Daphnia live in small glass jars in distilled water, kept at a fairly constant temperature. Twice a week they are fed algae food mixture and YCT food solution. • Testing Daphnia pulex: Isolate adults from the young. Only Daphnia less than a week old will be used for testing.

5. Methods • Measure equal amounts of water in to four containers, and add varying amounts of salt to each, creating four unique salinities.

6. Methods • Conduct the experiment in one once cups, placing five daphnia in each. • Run test for one and a half weeks.

7. Data and Analysis • None yet… But soon. 

8. Importance • Daphnia pulex are a major food source for many freshwater animals. • Global climate change is causing salinity levels to fluctuate all over the world. • Daphnia pulex can be used as an indicator species. http://daphnia.cgb.indiana.edu/images/Daphnia_DGC.png

9. Conclusion • None yet… But soon. 

10. Bibliography and Acknowledgements • CH2M Hill