Systematics of the Laurencia complex (Rhodomelaceae, Rhodophyta) in southern Africa By Caitlynne Melanie Francis Thesis submitted in fulfilment of requirements for the degree of Doctor of Philosophy of Science in the Department of Biological Sciences in the Faculty of Science, University of Cape Town, South Africa UniversityMay of 2014 Cape Town Supervisor: Professor John J. Bolton1 Co-Supervisors: Dr Lydiane Mattio1 & Associate Professor Robert J. Anderson1, 2 1Department of Biological Sciences, Marine Research Institute, University of Cape Town, Rondebosch 7701, South Africa 2Seaweed Research, Department of Agriculture, Forestry and Fisheries, Private Bag X2, Roggebaai 8012, South Africa I The copyright of this thesis vests in the author. No quotation from it or information derived from it is to be published without full acknowledgement of the source. The thesis is to be used for private study or non- commercial research purposes only. Published by the University of Cape Town (UCT) in terms of the non-exclusive license granted to UCT by the author. University of Cape Town DECLARATION I declare that this thesis is my own, unaided work and has not been submitted in this or any form to another university. Where use has been made of the research of others, it has been duly acknowledged in the text. Work discussed in this thesis was carried out under the supervision of Professor JJ Bolton and Dr Lydiane Mattio of the Department of Biological Sciences, University of Cape Town and Associate Professor RJ Anderson of Department of Agriculture, Forestry and Fisheries and the Department of Biological Sciences, University of Cape Town. ____________________ Caitlynne Melanie Francis Department of Biological Sciences, University of Cape Town May 2014 II TABLE OF CONTENTS TITLE PAGE ................................................................................................................ I DECLARATION ......................................................................................................... II TABLE OF CONTENTS ............................................................................................. III LIST OF FIGURES ...................................................................................................... VI LIST OF TABLES ....................................................................................................... VIII ACKNOWLEDGEMENTS ......................................................................................... IX ABSTRACT ................................................................................................................. X CHAPTER 1: GENERAL INTRODUCTION 1.1 Seaweeds .................................................................................................... 1 1.2 Economic and chemical importance of seaweeds ...................................... 2 1.3 General Biology and taxonomy of Rhodophyta ......................................... 4 1.4 Systematics of the genus Laurencia and the Laurencia complex .............. 10 1.5 Geographical distribution of the Laurencia complex ................................. 16 1.6 South Africa and Laurencia ........................................................................ 20 CHAPTER 2: MOLECULAR SYSTEMATICS OF THE LAURENCIA COMPLEX (RHODOMELACEAE, RHODOPHYTA) IN SOUTH AFRICA 2.1 Introduction ................................................................................................ 27 2.2 Materials and Methods ............................................................................... 29 2.3 Results ........................................................................................................ 34 2.4 Discussion ................................................................................................... 41 III CHAPTER 3: DESCRIPTIONS OF AND KEY TO SOUTH AFRICAN SPECIES IN THE LAURENCIA COMPLEX, WITH THE ADDITION OF FIVE NEW SPECIES 3.1 Introduction ................................................................................................ 44 3.2 Materials and Methods ............................................................................... 47 3.3 Results & Discussion ................................................................................. 48 Morphological Descriptions ................................................................. 50 Laurencia brongniartii ............................................................. 50 Laurencia complanata ............................................................. 52 Laurencia cf. corymbosa .......................................................... 54 Laurencia dehoopiensis sp. nov. .............................................. 56 Laurencia dichotoma sp. nov. .................................................. 57 Laurencia digitata sp. nov. ....................................................... 59 Laurencia cf. elata ............................................................. 60 Laurencia flexuosa ............................................................. 62 Laurencia glomerata ............................................................ 65 Laurencia multiclavata sp. nov. ............................................... 67 Laurencia natalensis ............................................................ 69 Laurencia pumila ............................................................. 71 Laurencia sodwaniensis sp. nov. .............................................. 73 Laurencia stegengae nom. nov. ................................................ 74 Taxonomic Key .................................................................................... 76 New Records for the Laurencia complex and additional notes ........... 78 Plates ..................................................................................................... 81 IV CHAPTER 4: PHYLOGENY AND BIOGEOGRAPHY OF THE LAURENCIA COMPLEX, WITH EMPHASIS ON THE SOUTH WEST INDIAN OCEAN 4.1 Introduction ................................................................................................ 97 4.2 Materials and Methods ............................................................................... 100 4.3 Results ........................................................................................................ 105 4.4 Discussion ................................................................................................... 114 CHAPTER 5: GENERAL DISCUSSION ................................................................... 125 REFERENCES ............................................................................................................. 134 APPENDICES .............................................................................................................. 169 V LIST OF FIGURES Figure 1.1: An illustration of the Laurencia sensu stricto life history. ……………………… 6 Figure 1.2 Simplified phylogeny of the Laurencia complex, based on the rbcL gene region 14 Figure 1.3: Known distribution of Laurencia sensu stricto (red outline) along the southern African coast. ……………………………………………………………………………… 22 Figure 2.1: Sampling sites on the west coast and the western & central portion of the south coast. ……………………………………………………………………………………… 30 Figure 2.2: Sampling sites on the eastern portion of the south coast, and the east coast 31 Figure 2.3: The 50% majority-rule Bayesian inference tree depicting the phylogenetic relationships between species of the South African Laurencia complex as inferred from the plastid rbcL gene region under a GTR + I + G model of sequence evolution. …………….. 36 Figure 3.1: Laurencia brongniartii ……………………………………………………… 81 Figure 3.2: Laurencia complanata ……………………………………………………… 82 Figure 3.3: Laurencia cf. corymbosa ……………………………………………………… 83 Figure 3.4: Laurencia dehoopiensis sp. nov. ……………………………………………… 84 Figure 3.5: Laurencia dichotoma sp. nov. ………………………………………………… 85 Figure 3.6: Laurencia digitata sp. nov. …………………………………………………… 86 Figure 3.7: Laurencia cf. elata ……………………………………………………………. 87 Figure 3.8: Laurencia flexuosa ……………………………………………………………. 88 Figure 3.9: Laurencia glomerata ………………………………………………………….. 89 VI Figure 3.10: Laurencia multiclavata sp. nov………………………………………………. 90 Figure 3.11: Laurencia natalensis …………………………………………………………. 91 Figure 3.12: Laurencia pumila …………………………………………………………….. 92 Figure 3.13: Laurencia sodwaniensis sp. nov. …………………………………………….. 93 Figure 3.14: Laurencia stegengae nom. nov. ……………………………………………… 94 Figure 3.15: Undescribed morphotypes of the Laurencia complex in South Africa …… 95-96 Figure 4.1: Map of the South Western Indian Ocean displaying collection localities ……. 101 Figure 4.2: The 50% majority consensus Bayesian phylogeny of the Laurencia complex in the SWIO inferred from the plastid marker rbcL ………………………………………… 108 Figure 4.3: The 50% majority consensus Bayesian phylogeny of the Laurencia complex in the ocean regions of the world inferred from the plastid marker rbcL ……………………. 113 Figure A1: Submorphotypes of Laurencia cf. corymbosa ………………………………... 199 VII LIST OF TABLES Table 1.1: Distinguishing characters used to identify the different genera in the Laurencia complex following Martin-Lescanne et al. (2010) ……………………………………... 17-18 Table 1.2: Laurencia complex species recorded from South Africa prior to this study (from Seagrief 1984, Silva et al. 1996, Stegenga et al. 1997 and De Clerck et al. 2005) showing whether or not they have been sequenced with the plastid gene, rbcL. …………………… 24 Table 2.1: The intergeneric, interspecific and intraspecific divergence values obtained for rbcL sequences of the Laurencia