Degree Name

MS (Master of Science)



Date of Award


Committee Chair or Co-Chairs

Lev Yampolsky

Committee Members

Joseph Bidwell, Aruna Kilaru


Organisms adapt to their environments by adjusting their biochemistry and physiology; such adaptation is limited by resource availability and physiological constraints. The freshwater crustacean Daphnia magna inhabits a wide range of environments and must survive and reproduce within a range of temperatures. One limit to low-temperature adaptation is thought to be the availability of unsaturated fatty acids necessary to maintain proper fluidity of cellular membranes. D. magna maintained at 10 ºC on a diet poor in unsaturated fatty acids have been observed to produce clutches that fail to develop. However, this has not been observed on a diet rich in unsaturated fatty acids or at a higher temperature regardless of diet. Clonal variation is commonly seen in D. magna life history traits, including heat tolerance, and was also investigated. D. magna were kept at two temperatures and fed two algal diets that differ in unsaturated fatty acid content. To investigate the role of fatty acid composition on the reproductive success of D. magna, fatty acids were extracted from adults and eggs. Of the twenty-one clones studied, no clonal variation was seen in the ability to produce successful clutches at 10 °C on a diet poor in unsaturated fatty acids. Gas chromatography revealed significant differences in 20-carbon fatty acids and suggest a parent-offspring conflict over a limited resource.

Document Type

Thesis - unrestricted


Copyright by the authors.