The current investigation identified fatty acids (FAs) and quantified total and specific FA concentrations in the striped shore crab, Pachygrapsus crassipes. I examined changes in the abundance of individual FAs and FA saturation categories (saturated, monounsaturated, polyunsaturated) over months and between sexes. Fatty acid fluctuations were compared with reported temperatures from a location near the collection site to determine whether temperature significantly contributed to these changes. The abundances of palmitoleic acid, palmitic acid, and docosahexaenoic acid (DHA) were found to fluctuate significantly on a monthly basis, with a higher abundance in warm months than in cold months. This fluctuation appeared to be independent of temperature, however, as an increase in FA abundance between February and April preceded an increase in temperature. I did not find a significant difference in FA abundance between females and males. Saturation levels were only different between sexes when monounsaturated FAs (MUFA) were lower in males than in females in December. No overall difference existed between sexes. Therefore, results for sexes were pooled for subsequent analyses.

Changes in FAs could be an acclimatory mechanism used by P. crassipesto take advantage of their biochemical properties in different temperatures. I concluded that while temperature may affect FA abundance, there may be other underlying factors influencing FA abundance. These factors may include molting, seasonality of food abundance, mating, and reproduction. The results of this study may serve as a comparative model for other shore crabs, as well as to establish baseline values of existing FA concentrations in P. crassipes for use in future research.

LLU Discipline





School of Science and Technology

First Advisor

Stephen G. Dunbar

Second Advisor

Danilo S. Bošković

Third Advisor

William K. Hayes

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Crabs -- Physiological effect -- Southern California; Fatty acids -- Metabolism; Ocean temperature.



Page Count

xiv; 84

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives