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The phylogeographic population structure of the Cape sea urchin, Parechinus angulosus

Thesis (MSc)--Stellenbosch University, 2011.

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Main Author: Muller, Cornelius Marthinus
Other Authors: Matthee, C. A.
Format: Thesis
Language:en_ZA
Published: Stellenbosch : Stellenbosch University 2011
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access_status_str Open Access
author Muller, Cornelius Marthinus
author2 Matthee, C. A.
author_browse Matthee, C. A.
Muller, Cornelius Marthinus
author_facet Matthee, C. A.
Muller, Cornelius Marthinus
author_sort Muller, Cornelius Marthinus
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (MSc)--Stellenbosch University, 2011.
format Thesis
id oai:scholar.sun.ac.za:10019.1/6899
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:44:46.833Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2011
publishDateRange 2011
publishDateSort 2011
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
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source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/6899 The phylogeographic population structure of the Cape sea urchin, Parechinus angulosus Muller, Cornelius Marthinus Matthee, C. A. Von der Heyden, Sophie Bowie, Rauri C. K. Stellenbosch University. Faculty of Science. Dept. of Botany and Zoology. Sea urchins Cape sea urchin Phylogeography Invertebrates Dissertations -- Zoology Theses -- Zoology Populations Thesis (MSc)--Stellenbosch University, 2011. ENGLISH ABSTRACT: South Africa's coastline is in the region of 3650kms and encompasses many different and dynamic marine environments. To enhance our current understanding of the population structure and gene flow patterns of intertidal zone marine species in this region, this study sets out to investigate the phylogeographic population structure of the Cape sea urchin, Parechinus angulosus, using mitochondrial and nuclear DNA sequence data collected in 2007 and 2008. Individuals were sampled from 18 geographic locations between southern Namibia and Durban, covering nearly the full extent of the species range. Sequence data were obtained from a 790bp region of the COI mtDNA gene (n=510) and a 182bp region of the nDNA SpREJ9 gene (n=145), respectively. The mtDNA data revealed 283 polymorphic sites (36%) defining 195 haplotypes, of which 160 were unique and 35 shared among individuals. Haplotype diversity (h) was found to be high both overall (h=0.95) and for individual localities (h=0.75-0.98), with nucleotide diversity (π) being low overall (π=0.013) as well as for individual localities (π=0.0033-0.0254). AMOVA revealed significant population structure among sampling sites in the Namaqua Province biogeographical region, as well as between three of the four respective coastal biogeographic provinces/regions. Gene flow was bi-directional among sampling sites in the south coast Agulhas and East Coast Province biogeographical regions, while gene flow in the Namaqua Province appears to be dominated by northwards movement. BAPS identified a significant break in the Cape Point region, which was also reflected in the gene flow patterns and parsimony networks. This broadly corresponds to previously identified biogeographic regions as well as genetic breaks for other marine species found along this coast. Fu's Fs statistics showed strong signal(s) of population expansion for individual sampling localities as well as for the data set as a whole, while MDIV estimated a time since expansion ranging from 7733-4759 years ago. The nDNA data revealed 54 variable sites (29.7%), defining 72 alleles of which 50 were unique and 22 shared among individuals. Many of the alleles (69.4%) were restricted to single sampling sites, with Betty's Bay on the south coast being the most diverse from a genetic viewpoint. Allelic diversity was high overall (h=0.86) while nucleotide diversity was low (π=0.025). No nuclear sub-group structure was identified by BAPS, although the parsimony network revealed shallow genetic structure between the Namaqua and Agulhas Provinces, with significant pairwise ФST values also recovered between their individual coastal localities. This points to at least one major barrier to gene flow for Parechinus angulosus along the South African coast, namely Cape Point. Several additional, smaller hindrances to gene flow along the coast were also identified, most of which are congruent with findings from studies on both other and sea urchin species. As a standalone study this research elucidated many aspects regarding the phylogeography of the Cape sea urchin, P. angulosus. However, it is when viewed in the broader context of invertebrate phylogeography along the southern African coastline that this research will provide its most critical insight. AFRIKAANSE OPSOMMING: Geen opsomming 2011-02-17T14:09:00Z 2011-03-15T08:46:06Z 2011-02-17T14:09:00Z 2011-03-15T08:46:06Z 2011-03 Thesis http://hdl.handle.net/10019.1/6899 en_ZA Stellenbosch University 92 p. : ill., maps application/pdf application/pdf Stellenbosch : Stellenbosch University
spellingShingle Sea urchins
Cape sea urchin
Phylogeography
Invertebrates
Dissertations -- Zoology
Theses -- Zoology
Populations
Muller, Cornelius Marthinus
The phylogeographic population structure of the Cape sea urchin, Parechinus angulosus
title The phylogeographic population structure of the Cape sea urchin, Parechinus angulosus
title_full The phylogeographic population structure of the Cape sea urchin, Parechinus angulosus
title_fullStr The phylogeographic population structure of the Cape sea urchin, Parechinus angulosus
title_full_unstemmed The phylogeographic population structure of the Cape sea urchin, Parechinus angulosus
title_short The phylogeographic population structure of the Cape sea urchin, Parechinus angulosus
title_sort phylogeographic population structure of the cape sea urchin parechinus angulosus
topic Sea urchins
Cape sea urchin
Phylogeography
Invertebrates
Dissertations -- Zoology
Theses -- Zoology
Populations
url http://hdl.handle.net/10019.1/6899
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