Biodiversity and Zoogeography of the Polychaeta (Annelida) in the deep Weddell Sea (Southern Ocean, Antarctica) and adjacent deep-sea basins Dissertation zur Erlangung des Grades eines Doktors der Naturwissenschaften der Fakultät für Biologie und Biotechnologie der Ruhr-Universität Bochum angefertigt im Lehrstuhl für Evolutionsökologie und Biodiversität der Tiere vorgelegt von Myriam Schüller aus Aachen Bochum 2007 Biodiversität und Zoogeographie der Polychaeta (Annelida) des Weddell Meeres (Süd Ozean, Antarktis) und angrenzender Tiefseebecken The most exciting phrase to hear in science, the one that heralds new discoveries, is not „EUREKA!“ (I found it!) but “THAT’S FUNNY…” Isaak Asimov US science fiction novelist & scholar (1920-1992) photo: Ampharetidae from the Southern Ocean, © S. Kaiser Title photo: Polychaete samples from the expedition DIVA II, © Schüller & Brenke, 2005 Erklärung Hiermit erkläre ich, dass ich die Arbeit selbständig verfasst und bei keiner anderen Fakultät eingereicht und dass ich keine anderen als die angegebenen Hilfsmittel verwendet habe. Es handelt sich bei der heute von mir eingereichten Dissertation um fünf in Wort und Bild völlig übereinstimmende Exemplare. Weiterhin erkläre ich, dass digitale Abbildungen nur die originalen Daten enthalten und in keinem Fall inhaltsverändernde Bildbearbeitung vorgenommen wurde. Bochum, den 28.06.2007 ____________________________________ Myriam Schüller INDEX iv Index 1 Introduction 1 1.1 The Southern Ocean 2 1.2 Introduction to the Polychaeta 4 1.2.1 Polychaete morphology 5 1.2.1.1 Ampharetidae MALMGREN 1866 7 1.2.1.2 Glyceridae GRUBE 1850 7 1.2.1.3 Goniadidae KINBERG 1866 8 1.2.1.4 Hesionidae GRUBE 1850 8 1.2.1.5 Nephtyidae GRUBE 1850 8 1.2.1.6 Nereididae JOHNSTON 1865 9 1.2.1.7 Opheliidae MALMGREN 1867 9 1.2.1.8 Sabellariidae JOHNSTON 1865 10 1.2.1.9 Scalibregmatidae MALMGREN 1867 10 1.2.1.10 Sphaerodoridae MALMGREN 1867 11 1.2.1.11 Syllidae GRUBE 1850 11 1.2.1.12 Terebellidae MALMGREN 1867 12 1.2.1.13 Trichobranchidae MALMGREN 1866 12 1.2.2 Polychaete ecology, reproduction and feeding strategies 13 1.2.2.1 Ampharetidae MALMGREN 1866 14 1.2.2.2 Glyceridae GRUBE 1850 15 1.2.2.3 Goniadidae KINBERG 1866 15 1.2.2.4 Hesionidae GRUBE 1850 16 1.2.2.5 Nephtyidae GRUBE 1850 16 1.2.2.6 Nereididae JOHNSTON 1865 16 1.2.2.7 Opheliidae MALMGREN 1867 17 1.2.2.8 Sabellariidae JOHNSTON 1865 17 1.2.2.9 Scalibregmatidae MALMGREN 1867 17 1.2.2.10 Sphaerodoridae MALMGREN 1867 18 1.2.2.11 Syllidae GRUBE 1850 18 1.2.2.12 Terebellidae MALMGREN 1867 19 INDEX v 1.2.2.13 Trichobranchidae MALMGREN 1866 19 1.2.3 Polychaete systematics 19 2 Material and methods 21 2.1 The expeditions ANDEEP I, II, and III: sampling and on-board treatment 21 2.2 Taxonomic analyses 24 2.2.1 Final sorting, identification, and labeling of species 24 2.2.2 Description of new species 24 2.2.3 Construction of identification keys 25 2.3 Univariate and multivariate community analyses 25 2.3.1 Species accumulation plots 25 2.3.2 Standardization and transformation of sampling data 25 2.3.3 Univariate biodiversity measures 26 2.3.4 Similarity measures 27 2.3.5 Comparison of EBS epi- and supranets 27 2.3.6 Cluster analysis and MDS plotting 28 2.3.7 Environmental factors and species sets explaining station similarities 29 2.3.7.1 BIO-ENV 29 2.3.7.2 BV Step 30 2.3.8 Average Taxonomic Distinctness (AvTD) and Variations in Taxonomic Distinctness (VarTD) 31 2.4 Reconstruction of vertical and global distribution patterns 32 2.4.1 Vertical distribution patterns 32 2.4.2 Global distribution patterns 32 3 Results 33 3.1 Composition of polychaete communities 33 3.2 Identification keys to selected species found during ANDEEP I-III 34 3.2.1 Key to the Ampharetidae MALMGREN 1866 34 3.2.2 Glyceridae GRUBE 1850 41 3.2.3 Key to the Goniadidae KINBERG 1866 42 INDEX vi 3.2.4 Key to the Hesionidae GRUBE 1850 43 3.2.5 Key to the Nephtyidae GRUBE 1850 45 3.2.6 Key to the Nereididae JOHNSTON 1865 46 3.2.7 Key to the Opheliidae MALMGREN 1867 47 3.2.8 Sabellariidae JOHNSTON 1865 51 3.2.9 Key to the Scalibregmatidae MALMGREN 1867 52 3.2.10 Key to the Sphaerodoridae MALMGREN 1867 56 3.2.11 Key to the Syllidae GRUBE 1850 58 3.2.12 Key to the Terebellidae MALMGREN 1867 64 3.2.13 Key to the Trichobranchidae MALMGREN 1866 71 3.3 Descriptions of new species 73 3.3.1 Ampharetidae MALMGREN 1866 73 3.3.1.1 Anobothrus pseudoampharete sp.n. 73 3.3.2 Hesionidae GRUBE 1850 76 3.3.2.1 Amphiduros serratus sp.n. 76 3.3.2.2 Micropodarke cylindripalpata sp.n. 77 3.3.2.3 Ophiodromus calligocervix sp.n. 78 3.3.2.4 Parasyllidea delicata sp.n. 79 3.3.3 Opheliidae MALMGREN 1867 83 3.3.3.1 Ammotrypanella MCINTOSH 1879 83 3.3.3.1.1 Ammotrypanella arctica MCINTOSH 1879 83 3.3.3.1.2 Ammotrypanella cirrosa sp.n. 84 3.3.3.1.3 Ammotrypanella mcintoshi sp.n. 86 3.3.3.1.4 Ammotrypanella princessa sp.n. 87 3.3.3.2 Ophelina ÖRSTED 1843 88 3.3.3.2.1 Ophelina ammotrypanella sp.n. 88 3.3.3.2.2 Ophelina robusta sp.n. 89 3.3.4 Scalibregmatidae MALMGREN 1867 93 3.3.4.1 Pseudoscalibregma papilia sp.n. 93 3.3.5 Sphaerodoridae MALMGREN 1867 94 3.3.5.1 Ephesiella hartmanae sp.n. 94 3.3.5.2 Sphaerodoropsis HARTMAN & FAUCHALD 1971 95 INDEX vii 3.3.5.2.1 Sphaerodoropsis distincta sp.n. 95 3.3.5.2.2 Sphaerodoropsis maculata sp.n. 96 3.3.5.2.3 Sphaerodoropsis simplex sp.n. 98 3.4 Univariate and multivariate community analyses 101 3.4.1 Analysis of the epi- and supranet 101 3.4.2 Species richness and biodiversity 102 3.4.2.1 Species richness (Margalef’s Index) 103 3.4.2.2 Biodiversity and Evenness 105 3.4.3 Clustering and Multi Dimensional Scaling (MDS) 107 3.4.3.1 ANDEEP I-III 107 3.4.3.2 ANDEEP I/II 110 3.4.3.3 ANDEEP III 112 3.4.4 Correlation of polychaete communities to environmental data (BIO-ENV) 113 3.4.5 Correlation of species to stations similarities (BV Step) 115 3.4.6 Average Taxonomic Distinctness (AvTD) and Variation in Taxonomic Distinctness (VarTD) 115 3.5 Zoogeography 119 3.5.1 Vertical distribution patterns in the Southern Ocean 119 3.5.2 Global distribution patterns 119 4 Discussion 124 4.1 Efficiency of the gear and methods used for sampling 124 4.2 Polychaete abundance and family composition 126 4.3 Species identification, composition and descriptions of new species 129 4.3.1 Species composition of families 130 4.3.2 Descriptions of new species 131 4.3.2.1 Ampharetidae MALMGREN 1866 131 4.3.2.2 Hesionidae GRUBE 1850 132 4.3.2.3 Opheliidae MALMGREN 1867 133 4.3.2.4 Scalibregmatidae MALMGREN 1867 135 4.3.2.5 Sphaerodoridae MALMGREN 1867 136 INDEX viii 4.4 Polychaete diversity in the Southern Ocean 139 4.5 Similarities between sampling areas 143 4.6 Influence of environmental factors and species on similarities 146 4.7 Taxonomic diversity 148 4.8 Zoogeography and vertical distribution 150 4.8.1 Origin of the Southern Ocean deep-sea fauna 150 4.8.2 Vertical distribution 151 4.8.3 Global distribution patterns 152 5 Summary 158 5.1 Zusammenfassung 160 6 References 162 7 Appendix 180 7.1 Figures 180 7.2 Tables 204 8 Acknowledges 245 9 Lebenslauf 247 INTRODUCTION 1 1 Introduction During the austral summers of 2002 and 2005 the expeditions ANDEEP I-III took place to conduct one of the first thorough surveys concerning the faunal composition of the deep Weddell and Scotia Seas. Transects starting south of South Africa, crossing the Weddell Sea and the Drake Passage, and ending at the western coast of the Antarctic Peninsula were sampled with several gear gathering faunal as well as geological data. Since then specialists of different scientific backgrounds have analyzed the samples and put together a complex puzzle of taxonomy, systematics, zoogeography, and ecology of the epi- and infaunal communities in the deep Southern Ocean. As part of this approach, the polychaetes sampled with an epibenthic sledge (EBS) during ANDEEP I-III are focus of this study. Based on taxonomic analysis, a characterization of the polychaete communities in the deep Southern Ocean and the global zoogeography of the sampled species is achieved on a scale that is unique in its outline to date. Due to the high number of individuals in the samples, an analysis on a taxonomic level lower than family is only done for thirteen families, belonging to four different orders, respectively suborders, which are all common representatives of the deep-sea polychaete fauna world wide. These are the Ampharetidae, Sabellariidae, Terebellidae, Trichobranchidae (Terebellida), Glyceridae, Goniadidae, Nephtyidae, Sphaerodoridae (Glyceriformia), Hesionidae, Nereididae, Syllidae (Nereidiformia), Opheliidae, and Scalibregmatidae (Opheliida). The study includes a detailed taxonomic analysis of these families, analyses of their community structure, and descriptions of new species. In combination with biodiversity measures and ecological analyses, this approach will substantially contribute to our knowledge about the deep-sea benthos in the Southern Ocean. In addition, the global distribution patterns of the polychaete species sampled are reconstructed.