Prior to 1999, the harpacticoid copepod species Zausodes arenicolus had been considered to be very useful for ecological studies because its unusual shape made it easy to recognize. Bouck et al.'s (1999) taxonomic revision based on an evaluation of the morphology of specimens from the northern Gulf of Mexico near the Florida State University Coastal and Marine Laboratory split Z. arenicolus into three species, some of which co-occur. If Bouck et al. are correct, then the previous ecological results would be suspect, and Z. arenicolus would be much less useful in ecological work. It is therefore important to evaluate the validity of the species' boundaries they erected. Because convergent evolution and morphological stasis are known in harpacticoid copepods, morphologically based approaches such as those of Bouck et al. may not be sufficient. I decided to use gene-sequencing methods instead, but I saved voucher material from each specimen so I could search for new morphological characters if the initial morphological identifications and those indicated by gene sequences did not agree. A 393-base-pair region of the mitochondrial cytochrome b gene and a 478-base-pair region of the 18S rRNA gene were separately analyzed from individual Zausodes-complex specimens found at five sites within 30 km of the Florida State University Coastal and Marine Laboratory. Zausodes septimus individuals formed a single cytochrome b gene-sequence clade, whereas Z. arenicolus individuals formed five clades. The uncorrected genetic divergences among these clades were ten times greater than the divergences within them, a degree of differences that suggests that each clade is a different species. The 18S rDNA results support those from cytochrome b. Subsequent analysis of the vouchers revealed morphological differences that will allow two of the Z. arenicolus clades to be described as new species. Further analysis may reveal morphological differentiation among the other three clades. In sum, Bouck et al. (1999) perceived some but not all of the species present. / A Thesis submitted to the Department of Oceanography in partial fulfillment of the requirements for the degree of Master of
Science. / Spring Semester, 2009. / February 26, 2009. / Species Boundary, Copepoda, Harpacticoida, Zausodes, Cytochrome b, 18 S rRNA Gene, Gene Sequencing / Includes bibliographical references. / David Thistle, Professor Directing Thesis; Amy Baco-Taylor, Committee Member; Joel Kostka, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_253865 |
| Contributors | Easton, Erin Elizabeth (authoraut), Thistle, David (professor directing thesis), Baco-Taylor, Amy (committee member), Kostka, Joel (committee member), Department of Earth, Ocean and Atmospheric Sciences (degree granting department), Florida State University (degree granting institution) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource, computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
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