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dc.contributor.advisorWing, Steveen_NZ
dc.contributor.authorOstrow, D. Gigien_NZ
dc.date.available2011-01-25T00:22:24Z
dc.date.copyright2004en_NZ
dc.identifierhttp://adt.otago.ac.nz/public/adt-NZDU20070308.144342en_NZ
dc.identifier.citationOstrow, D. G. (2004). Larval dispersal and population genetic structure of brachiopods in the New Zealand fiords (Thesis, Doctor of Philosophy). University of Otago. Retrieved from http://hdl.handle.net/10523/486en
dc.identifier.urihttp://hdl.handle.net/10523/486
dc.descriptionGenetic differentiation of Terebratella sanguinea in the New Zealand fiords: a dispersal barrier in the marine environment / D.G. Ostrow ... [et al.]. xiv, 162, XXVI leaves :ill. (some col.), maps ; 30 cm. Includes bibliographical references. "Submitted September 2004". University of Otago department: Marine Science
dc.description.abstractNew Zealand's fourteen deep-water fiords have complex physical and hydrographic features as well as strong environmental gradients, all of which may influence the population structure of organisms that inhabit the fiords. I examined the population structure of the brachiopod Terebratella sanguinea over ecological and evolutionary time scales in relation to physical and hydrographic features of the fiords. To further explore the role of larval dispersal in this system, comparisons between population genetic structure of T. sanguinea and a brachiopod with a contrasting larval dispersal strategy (Liothyrella neozelanica) were made. Aspects of the life history of the articulate brachiopod Terebratella sanguinea were measured. I measured density and size throughout Doubtful Sound and growth at outer (5 km from outer coast) and inner fiord sites (13.5 km from outer coast). Additionally, reproductive periodicity was measured at a single site within Doubtful Sound. Terebratella sanguinea occurred at significantly lower densities and was significantly smaller at the outer fiord site (p lt; 0.05), however growth rates between an inner and outer fiord site did not differ significantly. Terebratella sanguinea was found to have separate sexes and synchronous maturation of oocytes with spawning occurring in the austral winter. These results indicated that, on an ecological time scale, the environmental gradient of the fiords influences aspects of T. sanguinea population structure. In order to determine the influence of the fiord environment on genetic population structure, patterns among T. sanguinea from across Fiordland were assessed using two genetic markers, and these data were compared to hydrodynamic variables. Ten sites (322 individuals) were included in a preliminary allozyme analysis, and 20 sites (358 individuals) were used for the amplified fragment length polymorphism (AFLP) analysis. Patchy genetic differentiation was revealed with both markers, and a break between Long Sound and the other Fiordland sites was detected with AFLP markers. My results suggest hydrodynamic features of this region may isolate organisms that can disperse only during a planktonic larval phase, however this isolation is visible in genetic patterns only at the most extreme values of the hydrodynamic variables. To better understand how the fiord environment influences population structure of organisms that disperse via planktonic larvae, I compared population genetic structure of two sympatric brachiopod species that differ in planktonic larval duration. Genetic analysis using the AFLP technique revealed population structuring corresponding to the contrasting modes of larval dispersal. AMOVA analysis indicated Liothyrella neozelanica, a brachiopod that broods its larvae, had more limited exchange among sites within a fiord than did T. sanguinea, a brachiopod that does not brood its larvae. In general, the fiord hydrographic conditions may be creating opportunities for local genetic differentiation (for example Long Sound) in organisms capable of longer distance dispersal, but organisms with lower potential for dispersal are more strongly influenced by ontogeny than by hydrography. Understanding the population structure of some of the marine fauna of Fiordland is an important cornerstone for the developing management plan for the area. Conservation of the underwater resources of this World Heritage Area can be successful if the structure of the system and the mechanisms driving this structure are taken into account.en_NZ
dc.format.mimetypeapplication/pdf
dc.languageenen_NZ
dc.publisherUniversity of Otagoen_NZ
dc.rightshttp://www.otago.ac.nz/administration/policies/otago003228.htmlen_NZ
dc.rightsAll items in OUR Archive are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.
dc.rights.urihttp://www.otago.ac.nz/administration/policies/otago003228.html
dc.subjectbrachiopodaen_NZ
dc.subjectlarvaeen_NZ
dc.subjectdispersalen_NZ
dc.subjectgeneticsen_NZ
dc.subjectNew Zealanden_NZ
dc.subjectDoubtful Sounden_NZ
dc.titleLarval dispersal and population genetic structure of brachiopods in the New Zealand fiordsen_NZ
dc.typeThesisen_NZ
thesis.degree.disciplineDepartment of Marine Scienceen_NZ
thesis.degree.nameDoctor of Philosophyen_NZ
thesis.degree.grantorUniversity of Otagoen_NZ
thesis.degree.levelDoctoral Thesesen_NZ
otago.interloanyesen_NZ
otago.openaccessOpen
dc.identifier.voyager1353121
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