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Date of Award


Document Type


Degree Name

Master of Science (M.S.)


Biological Sciences

First Advisor

Edmund H. Smith

First Committee Member

John S. Tucker

Second Committee Member

W. Michael Kaill


This study describes the structure and function of the alimentary tracts of B. zonalis and C. californica with particular emphasis on the stomach and style sac region. Both species were found to be generally similar to other styles bearing mesogastropods in that they have little or no development of glandular tissue in the esophageal region and a functional style is present in the stomach. The stomachs of both species are specialized to transport and digest a continuous supply of detritus by means of complex ridges, grooves and ciliary currents. C. californica appears more highly specialized for feeding on fine, highly organic detrital material than B. zonalis due to slightly more complex stomach morphology. A positive correlation is postulated between the length of the crystalline style, relative to shell height, and the percentage of organic matter in the detritus ingested.



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