The larval nutritional mode of marine invertebrates is an important life history trait that has strong effects on their ecology and evolution. Increases in egg size and transitions from feeding to nonfeeding larvae have happened repeatedly. In Spiralia, a change in cytoplasm allocated to macromeres at the 8-cell stage (that could delay the development of a functional gut) may accompany these transitions. The first part of this thesis describes the development of the gastropod Crepidula williamsi and compares it to the closely related C. fornicata, with a focus on changes in allocation to macromeres and the development of a functional gut. The second part is a phylogenetic comparison of egg size and allocation to macromeres in 44 species of spiralians, which revealed a significant correlation between the two. A phylogenetic comparison like this one has not previously been done on the development of such diverse marine invertebrate taxa.
|Commitee:||Livingston, Brian, Stankowich, Theodore|
|School:||California State University, Long Beach|
|School Location:||United States -- California|
|Source:||MAI 55/01M(E), Masters Abstracts International|
|Subjects:||Biology, Evolution and Development|
|Keywords:||Lecithotrophy, Macromeres, Planktotrophy, Spiralia|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be