TAXONOMY AND SYSTEMATICS OF SELECTED MARINE SOFT-BOTTOM FAN-WORMS (POLYCHAETA : SABELLIDAE : SABELLINAE) Sabine J. Cochrane A Thesis Submitted for the Degree of PhD at the University of St Andrews 2000 Full metadata for this item is available in Research@StAndrews:FullText at: http://research-repository.st-andrews.ac.uk/ Please use this identifier to cite or link to this item: http://hdl.handle.net/10023/7112 This item is protected by original copyright Taxonomy and systematics of selected marine soft-bottom fan-worms (Polychaeta: Sabellidae: Sabellinae) Sabine J. Cochrane 05.05.2000 A thesis submitted in fulfilment of the requirements of the University of St. Andrews for the degree of Doctor of Philosophy University of St. Andrews, Scotland/ Akvaplan-niva, Polar Environmental Centre, Troms0, Norway Declarations (i) I, Sabine 1. Cochrane, hereby certify that this thesis, which is approximately 67 000 words in length, has been written by me, that it is the record of work carried out by me and that it has not been submitted in any previous application for a higher degree. , '..;''; ~ '. , 4?':;:"o, =-~ / • ._ ._~ _- ....._~ . t ...... -:J. - -: ~.~-$=.; .;-- 05.05.2000 ... C ' " - . .... ... candidate (ii) I was admitted as a research student in September 1992 and as a candidate for the degree of PhD in September 1992; the higher study for which this is a record was carried out in Troms0, Norway, under supervision from the University of St. Andrews between 1992 and 1999. - -- - _ ';- _ .- ,,- . - ' -: 1'\'" , • .: ~" ~ f":'~ ...... - _ ' , 05 .05.2000 ..... :: ~ .- ....'-"'- "!--::e_M..'c~' : ~~ .: .. .. candidate (iii) I hereby certify that the candidate has fulfilled the conditions of the Resolutions and Regulations appropriate for the degree of PhD in the University of St. Andrews and that the candidate is qualified to submit this thesis in application for that degree. 05 .05 .2000 ... .... supervisor (iv) In submitting this thesis to the University of St. Andrews I understand that I am giving permission for it to be made available for use in accordance with the regulations of the University Library for the time being in force, subject to any copyright vested in the work not being affected thereby. I also understand that the title and abstract will be published, and that a copy of the work may be made and supplied to any bona fide library or research worker. ... -. ~ '. ~ ~ . 05 .05 .2000 .. .' ! - ,oJ-'r ~~ .. " - - _ ~ .. ... .. candidate Table of Contents Chapter Page Abstract Foreword ii Acknowledgements iv Sources of material vi Institute affiliations viii Financial sources vix 1. Introduction to the Sabellidae 1 1.1 Scope 1 1.2 Basic sabel lid morphology 3 1.3 Morphological characteristics of Chane, Euchone and 32 Jasmineira 1.4 Behaviour and the importance of scale 39 1.5 Glossary of terms 45 2. Taxonomic part 51 2.1 Acknowledgements 51 2.2 Introduction 51 2.3 Euchone Malmgren - historical and taxonomic perspectives 55 2.4 Euchone x from the northern North Sea and Norwegian Sea 67 2.5 Redescription of Jasmineira candela Grube and reinstatement 82 of Jasmineira oculata Langerhans 2.6 Taxonomic and systematic challenges within Chone Kn2lyer 114 3. Systematic part 149 3.1 A brief systematic history of the Sabellidae 149 3.2 Willi Hennig and phylogenetic systematics 153 3.3 "Tree-thinking" - some current issues in cladistics 173 3.4 Current phylogenetic status of the Sabellidae 209 3.5 Phylogenetic analyses of Euchone and related taxa 215 3.6 Could phylogenetic taxonomy resolve the "Chone complex"? 241 4. Ecological part: a study of Euchone x 246 4.1 Special thanks 246 4.2 Introduction 246 4.3 Materials and methods 247 4.4 Results and discussion 248 4.5 Conclusions 262 5. Concluding discussion 263 5.1 Achievements and contributions 263 5.2 Future directions and challenges 269 6. Reference list 273 Appendix I - List of characters and character states Appendix II - Character matrix II Concise Table of Contents Index of Figures Figure Abbreviated caption Page Introduction Chapter 1.2 Basic morphology 1.2.1 Generalised body plan of a hypothetical sabel lid 4 polychaete 1.2.2 Schematic illustration of 'feather-like' and 'snowflake-like' 7 radiolar crowns 1.2.3 Radiolar crown of Euchone x 8 1.2.4 Schematic illustration of three different lip structures 9 1.2.5 Schematic illustration of the different peristomial origins 10 of the sabellid collar 1.2.6 Various conditions of the fabriciin collar 11 1.2.7 Some variations in the form of the sabel lin collar 12 1.2.8 Modification of the anterior peristomial ring in some 13 Sabellinae to form a ventral peristomial extension 1.2.9 Elongate thoracic notochaetae 19 1.2.10 The main descriptive regions of sabellid elongate 21 chaetae 1.2.11 Some elongate chaetal types found within the Sabellidae 22 1.2.12 Some specialised forms of sabellid elongate chaetae 22 1.2.13 Examples of thoracic neurochaetae (uncini) 24 1.2.14 Examples of abdominal notochaetae (uncini) 25 1.2.15 Radiolar eyes in the Sabellidae 27 1.2.16 Transverse lateral section of the anterior of Euchone x 27 showing the otocyst 1.2.17 Examples of sabellid pygidia 29 Chapter 1.3 Morphology Chone 1.3.1 The dorsal gap 34 1.3.2 Dorso-Iateral view of a generalised sabellid collar in 34 expanded and flattened states 1.3.3 Relative positions of the different types of thoracic 35 notochaetae 1.3.4 The anal depression in Euchone 37 1.3.5 Two examples of the anal depression in Euchone 38 1.3.6 Atypical anal depression in Euchone limnicola 38 Index a/figures and tables Taxonomic part Chapter 2.3 Euchone Malmgren 2.3.1 Posterior of Amphicorina longipyge 64 2.3.2 Thoracic uncinus of Desdemona antarctica 65 2.3.3 Abdominal uncinus from Euchone rubrocincta 66 Chapter 2.4 Euchone x 2.4.1 Overview of general sampling area 69 2.4.2 Euchone x. External morphology 73 2.4.3 Euchone x. Thoracic notochaetae 74 2.4.4 Euchone x. Scanning electron micrograph of uncini 75 2.4.5 Euchone x. Radiolar crown 76 2.4.6 Schematic illustration of the two main types of sabellid 77 radioles Chapter 2.5 Jasmineira candela/oculata 2.5.1 Map showing the type locality of Jasmineira candela 86 2.5.2 Jasmineira candela: external anatomical features 92 2.5.3 Jasmineira candela: tips of two radioles without tips 95 2.5.4 Jasmineira oculata: chaetae and pygidium 97 2.5.5 Jasmineira oculata: ventral view and details of crown 100 2.5.6 Jasmineira oculata: lateral and dorsal views of anterior 101 2.5.7 Jasmineira oculata: scanning electron micrograph of 102 anterior 2.5.8 Jasmineira oculata: detail of distal part of radiolar crown 103 2.5.9 Jasmineira oculata: chaetae 104 Chapter 2.6 Chone challenges 2.6.1 Dorsal view of Chone near filicaudata 124 2.6.2 Ventro-Iateral view of Chone duneri 131 2.6.3 Chone duneri: anterior end 132 2.6.4 Chone duneri: chaetae 133 2.6.5 Chone y: lateral view of trunk 140 2.6.6 Chone y: scanning electron micrographs or radioles and 141 chaetae Index affigures and tables Systematic part Chapter 3.2 Willi Hennig 3.2.1 Structure of a hierarchy 157 3.2.2 Schematic representation of speciation 159 3.2.3 Illustration of plesiomorphy and apomorphy 160 3.2A The concept of monophyly at several chosen levels 164 3.2.5 Monophyletic, paraphyletic and polyphyletic groups 165 3.2.6 Demonstration of the principle of parsimony 168 Chapter 3.3 "Tree-thinking" 3.3.1 Comparison of approaches used in taxonomic 177 congruence 3.3.2 Plot of polychaete 'genera' and 'species' within 'families' 197 3.3.3 Three means of defining phylogenetic taxon names 204 Chapter 3A Phylogenetic status 3.4.1 Adams consensus tree (after Fitzhugh 1989) 211 Chapter 3.5 Analyses Euchone 3.5.1 Strict consensus tree of 68 individual trees 229 3.5.2 Four of the 68 minimum-length trees 230 3.5.3 Unambiguous changes shown on tree PAUP 21 232 3.5A Selected character state transformations (i) 233 3.5.5 Selected character state transformations (ii) 234 Chapter 3.6 Phylogenetic taconomy and Chone 3.6.1 Consensus tree used to demonstrate phylogenetic 242 taxonomy Ecological part Chapter4A Ecology Euchone x. 4.4.1 Euchone x. Various configurations of occupied tubes 249 4A.2 Euchone x. Dismantling the upper part of the tube 250 4.4.3 Euchone x. Emergence from the tube 251 4AA Euchone x. Suspension feeding 251 4.4.5 Euchone x. Surface deposit feeding 253 4.4.6 Euchone x. Longitudinal section of mature female 256 4.4.7 Euchone x. Adult with attached juvenile tube 258 4.4.8 Euchone x. Longitudinal section through brood mass 260 Index affigures and tables Index of Tables Table Abbreviated caption Page 2.3.1 List of Euchone Malmgren taxa with author affiliation 56 2.3.2 List of Euchone Malmgren taxa with synonyms 60 2.4.1 External features of Euchone x. and the most closely 79 related taxa 2.5.1 Main characters: Jasmineira candela and Jasmineira 106 oculata 3.3.1 Data matrix for a three taxon statement 168 3.4.1 Example of binary coding of a simple character 183 3.4.2 Illustration of multi-state coding 183 3.4.3 Example of binary coding of a 'complex' character 184 3.6.1 Terminal taxa included in the ingroup 219 Index affigures and tables Abstract The main descriptive characters of sabellid polychaetes are presented. Easily misunderstood morphological features are clarified by a series of schematic drawings.