Systematics of the Phasianelloidea In
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SYSTEMATICS OF THE PHASIANELLOIDEA IN SOUTHERN AFRICA (MOLLUSCA: GASTROPODA: VETIGASTROPODA) By TSHIFHIWA CONSTANCE NANGAMMBI Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy in the discipline of Zoology, School of Biological and Conservation Sciences, University of KwaZulu–Natal, Pietermaritzburg October, 2010 As the candidate’s Supervisor I agree/do not agree to the submission of this thesis. Signed:________________ Name:____________________ Date:_______________ The southern African pheasant shell species. i GENERAL ABSTRACT The taxonomy and biogeography of the southern African pheasant shell fauna are poorly known. Thirty–one nominal taxa referable to Phasianelloidea have been described or recorded in this region, but no systematic revision of these has ever been undertaken. Morphological evidence suggests that 16 taxa represent valid species, 13 are synonyms and two represent incorrect identifications. DNA sequence data from mitochondrial COI and 16S markers are used to assess the validity of the described nominal southern African Tricolia species. Phylogenetic analyses recovered seven distinct clades. Tricolia adusta, T. elongata, T. formosa, T. kochii, T. saxatilis and T. neritina were recovered as distinct species. Tricolia africana and T. capensis are genetically indistinguishable. However, morphological characters of the shell are clearly diagnosable. This could be due to incomplete sorting (ancestral polymorphism) reflecting recent speciation with rapid morphological and ecological divergence co–incident with geographical separation. Similarly, there is little genetic differentiation between T. bicarinata, T. insignis and T. kraussi. In this case the similarity is also supported by morphological data as the three species are conchologically close with intergrading shell characters, and might even be one species exhibiting ecogeographic variation in shell form. Monophyly of the southern African Tricolia species is not supported as well as the relationship between these and the European Tricolia pullus. In the last chapter a molecular phylogeny based on sequence data from mtDNA (COI and 16S), nuclear (18S and 28S) and the combined data (COI, 16S, 18S and 28S) is presented for the Phasianelloidea. Bayesian inference analyses performed on the combined data support the monophyly of Tricolia sensu stricto, Eulithidium and Phasianella. Tricolia sensu lato is not monophyletic, as its southern Australian and Indo–West Pacific species do not cluster with its southern African and Eastern Atlantic representatives. The position of Hiloa and Gabrielona within the Phasianelloidea is unresolved. Phylogenetic reconstructions using bayesian inference support monophyly of the Phasianelloidea. ii PREFACE The work described in this thesis was carried out in the School of Biological and Conservation Sciences, University of KwaZulu–Natal, Pietermaritzburg Campus, together with the Natal Museum, Pietermaritzburg, from January 2004 to June 2010, under the supervision of Dr David Herbert (Natal Museum) and co–supervision of Dr Rauri Bowie (Museum of Vertebrate Zoology and University of California, Berkeley), Dr Peter Teske (Rhodes University, Grahamstown), and Professor Denis Brothers (University of KwaZulu– Natal). This thesis, unless specifically indicated to the contrary in the text, represents original work by the author and has not been submitted in any form to another University. Where other work has been used, it has been acknowledged. Signed:_________________ T.C. Nangammbi (candidate) Signed:________________ Dr D.G. Herbert (supervisor) Signed:________________ Prof. D.J. Brothers (co–supervisor ) iii DECLARATION – PLAGIARISM I, TSHIFHIWA CONSTANCE NANGAMMBI, declare that 1. The research reported in this thesis, except where otherwise indicated, is my original research. 2. This thesis has not been submitted for any degree or examination at any other university. 3. This thesis does not contain other persons’ data, pictures, graphs or other information, unless specifically acknowledged as being sourced from other persons. 4. This thesis does not contain other persons' writing, unless specifically acknowledged as being sourced from other researchers. Where other written sources have been quoted, then: a. Their words have been re–written but the general information attributed to them has been referenced b. Where their exact words have been used, then their writing has been placed in italics and inside quotation marks, and referenced. 5. This thesis does not contain text, graphics or tables copied and pasted from the Internet, unless specifically acknowledged, and the source being detailed in the thesis and in the references sections. Signed____________________ iv DECLARATION – PUBLICATIONS Publication 1 (attached) Nangammbi, T.C. & Herbert, D.G. 2006. Two new species of Tricolia Risso, 1826 from South Africa (Mollusca: Gastropoda: Phasianellidae). African Invertebrates 47: 11-22. Publication 2 (attached) Nangammbi, T.C. & Herbert, D.G. 2008. A new species of pheasant shell from the south– western Indian Ocean (Mollusca: Gastropoda: Vetigastropoda: Phasianellidae: Tricolia). African Invertebrates 49(2): 13-19. The contribution of the authors of the above publications was the same. These papers represent the results of my study with input from Dr Herbert and which included presentation of the manuscripts, editing and guidance through the publication process. Signed:______________________ DISCLAIMER NOTE: This thesis, except for the attached publications, is not intended to form part of the permanent scientific record; it is itself therefore not a valid publication for the purposes of zoological nomenclature. v DEDICATION To my late mother Vho–Tshithudivha Maria Nangammbi vi TABLE OF CONTENTS GENERAL ABSTRACT ......................................................................................................... i PREFACE ............................................................................................................................. ii DECLARATION – PLAGIARISM ......................................................................................... iii DECLARATION – PUBLICATIONS .................................................................................... iv DISCLAIMER....................................................................................................................... iv DEDICATION........................................................................................................................ v TABLE OF CONTENTS ...................................................................................................... vi LIST OF TABLES ................................................................................................................ xi LIST OF FIGURES ............................................................................................................. xii LIST OF APPENDICES ..................................................................................................... xvi ACKNOWLEDGEMENTS ................................................................................................. xvii LIST OF ABBREVIATIONS ................................................................................................ xx GENERAL INTRODUCTION ................................................................................................ 1 CHAPTER 1: LITERATURE REVIEW .................................................................................. 3 1.1. HISTORICAL REVIEW OF PHEASANT SHELL CLASSIFICATION (PHASIANELLIDAE SENSU LATO) .................................................................................... 3 1.2. CHARACTERS IDENTIFIED BY VARIOUS AUTHORS IN THEIR PLACEMENT OF PHEASANT SHELL GENERA ............................................................................................. 9 1.2.1. Shell surface or sculpture .................................................................................... 11 1.2.2. Shell pigments .................................................................................................... 12 1.2.3. Shell microstructure ............................................................................................ 12 1.2.4. The number of shell muscles .............................................................................. 12 1.2.5. Protoconch .......................................................................................................... 13 1.2.6. Operculum .......................................................................................................... 13 vii 1.2.7. Radula ................................................................................................................ 14 1.2.8. Soft tissue ........................................................................................................... 18 1.2.9. Jaw ..................................................................................................................... 19 1.2.10. Sperm morphology .......................................................................................... 20 1.3. PHEASANT SHELL SYSTEMATICS ..................................................................... 20 1.3.1. Morphological data analyses............................................................................ 20 1.3.2. DNA sequence analyses .................................................................................. 23 1.4. CURRENT CLASSIFICATION OF THE PHEASANT SHELL SUBFAMILIES ....... 25 1.4.1. The