Phylogeny of Echiura (Annelida, Polychaeta) inferred from morphological and molecular data-implications for character evolution Dissertation zur Erlangung des Doktorgrades (Dr. rer. nat.) der Mathematisch-Naturwissenschaflichen Fakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn Vorgelegt von Janina Lehrke aus Berlin Bonn 2011 Angefertigt mit Genehmigung der Mathematisch-Naturwissenschaftlichen Fakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn erster Gutachter: Prof. Dr. Thomas Bartolomaeus Institut für Evolutionsbiologie Math. Nat. Fakultät Uni Bonn zweiter Gutachter: Privat-Dozent Dr. Lars Podsiadlowski Institut für Evolutionsbiologie Math. Nat. Fakultät Uni Bonn Datum der Disputation: 31.05.2012 Erscheinungsjahr: 2012 Contents 1 General Introduction ......................................................................................................................... 1 1.1 Characterization of Echiura ........................................................................................................... 1 1.2 Phylogeny of Echiura .................................................................................................................... 3 1.3 Aims of the present study .............................................................................................................. 5 2 Material and Methods ........................................................................................................................ 9 2.1 Molecular data ............................................................................................................................. 9 2.1.1 Taxon sampling ...................................................................................................................... 9 2.1.2 PCR Amplification, purification and sequencing ................................................................. 12 2.1.3 Phylogenetic Analysis .......................................................................................................... 14 2.2 Morphological data ................................................................................................................... 15 2.2.1 Studied species ..................................................................................................................... 15 2.2.2 Rearing of larvae .................................................................................................................. 17 2.2.3 Histology and light microscopy ............................................................................................ 18 2.2.4 Transmission electron microscopy (TEM) ........................................................................... 18 2.2.5 Scanning electron microscopy (SEM) .................................................................................. 19 2.2.6 Confocal laserscan microscopy (cLSM) .............................................................................. 20 2.2.7 Cladistic analysis .................................................................................................................. 21 3 Results ............................................................................................................................................... 25 3.1 Spermatozoa ............................................................................................................................... 25 3.1.1 Thalassema thalassemum (Thalassematidae) ....................................................................... 25 3.1.2 Echiurus echiurus (Echiuridae) ............................................................................................ 26 3.2 Anal sacs ..................................................................................................................................... 28 3.2.1 Thalassema thalassemum (Thalassematidae) ....................................................................... 28 3.2.2 Anal sac morphology in additional species .......................................................................... 35 3.2.2.1 Bonelliidae ............................................................................................................... 37 3.2.2.2 Thalassematidae ...................................................................................................... 41 3.2.2.3 Urechidae ................................................................................................................. 44 3.3 Larval protonephridia in Thalassema thalassemum (Thalassematidae) ............................... 49 3.4 Gonostomal lips ......................................................................................................................... 53 3.4.1 Thalassematidae ................................................................................................................... 53 3.4.2 Urechidae.............................................................................................................................. 56 3.4.3 Bonelliidae ............................................................................................................................ 57 3.5 Phylogenetic analysis of sequence data .................................................................................... 59 4 Discussion .......................................................................................................................................... 61 4.1 Spermatozoa .............................................................................................................................. 62 4.1.1 Comparison within Echiura .................................................................................................. 62 4.1.2 Conclusion ............................................................................................................................ 65 4.2 Anal sacs ..................................................................................................................................... 66 4.2.1 Identity of anal sacs .............................................................................................................. 66 4.2.2 Comparison within Echiura .................................................................................................. 69 4.2.2.1 Characterization of substructures ............................................................................. 70 4.2.2.2 Characters and character discussion ......................................................................... 73 4.2.2.3 Problematic character states ..................................................................................... 84 4.2.3 Conclusion ............................................................................................................................ 89 4.3 Larval protonephridia .............................................................................................................. 90 4.3.1 Comparison within Echiura .................................................................................................. 90 4.3.2 Conclusion ............................................................................................................................ 94 4.4 Gonostomal lips ......................................................................................................................... 95 4.4.1 Comparison within Echiura .................................................................................................. 97 4.4.2 Problematic character states ............................................................................................... 101 4.4.3 Conclusion .......................................................................................................................... 104 4. 5 Additional characters ............................................................................................................. 106 4.5.1 Chaetae .............................................................................................................................. 107 4.5.2 Post-pharyngeal diaphragm ............................................................................................... 109 4.5.3 Probosces ............................................................................................................................ 110 4.5.4 Glandular girdle .................................................................................................................. 112 4.5.5 Hemal system ..................................................................................................................... 113 4.5.6 Cloaca ................................................................................................................................. 113 4.5.7 Sexual dimorphism ............................................................................................................. 113 4.5.8 Arrangement of gonoducts ................................................................................................. 115 4.6 Phylogeny of Echiura .............................................................................................................. 116 4.6.1 Cladistic analysis of morphological data ............................................................................ 116 4.6.1.1 Favoured morphological tree ................................................................................. 117 4.6.2 Molecular tree ..................................................................................................................... 121 4.6.3 Comparison of phylogenetic