THE EVOLUTION OF MALE AND FEMALE REPRODUCTIVE TRAITS IN SIMULTANEOUSLY HERMAPHRODITIC TERRESTRIAL GASTROPODS Inauguraldissertation zur Erlangung der Würde eines Doktors der Philosophie vorgelegt der Philosophisch-Naturwissenschaftlichen Fakultät der Universität Basel von Kathleen Beese aus Friedrichroda, Deutschland Basel, 2007 Genehmigt von der Philosophisch-Naturwissenschaftlichen Fakultät der Universität Basel auf Antrag von Prof. Dr. Bruno Baur PD Dr. Andreas Erhardt Basel, den 13.02.2007 Prof. Dr. Hans-Peter Hauri Dekan 3 TABLE OF CONTENTS SUMMARY..............................................................................................................................................................9 GENERAL INTRODUCTION............................................................................................................................11 SEXUAL SELECTION AND SEXUAL CONFLICT......................................................................................................11 POSTMATING CONFLICT IN HERMAPHRODITES...................................................................................................12 REPRODUCTIVE MORPHOLOGIES IN STYLOMMATOPHORAN GASTROPODS........................................................13 OUTLINE OF THE THESIS .....................................................................................................................................14 CHAPTER I – EVOLUTION OF FEMALE SPERM STORAGE ORGANS IN THE CARREFOUR OF STYLOMMATOPHORAN GASTROPODS .............................................................................................17 ABSTRACT...........................................................................................................................................................17 INTRODUCTION ...................................................................................................................................................18 MATERIALS AND METHODS ................................................................................................................................21 Sampling and carrefour complexity .............................................................................................................21 Reproductive characters ...............................................................................................................................21 Life history and habitat specificity ...............................................................................................................22 Carrefour length and sperm length ..............................................................................................................23 Molecular data and phylogenetic analyses..................................................................................................24 Ancestral character states and character association.................................................................................25 RESULTS..............................................................................................................................................................28 Phylogeny ......................................................................................................................................................29 Carrefour complexity and spermatheca evolution.......................................................................................28 Carrefour associations with reproductive characters .................................................................................30 Associations with life history and habitat specificity...................................................................................30 Variation in carrefour length and sperm length ..........................................................................................31 DISCUSSION.........................................................................................................................................................33 Reproductive characters and postcopulatory sexual selection ...................................................................34 Influence of life history and habitat specificity............................................................................................36 Carrefour size and sperm length evolution..................................................................................................36 Conclusions ...................................................................................................................................................38 ACKNOWLEDGEMENTS .......................................................................................................................................38 APPENDIX............................................................................................................................................................39 CHAPTER II – COEVOLUTION OF MALE AND FEMALE REPRODUCTIVE TRAITS IN A SIMULTANEOUSLY HERMAPHRODITIC LAND SNAIL........................................................................43 ABSTRACT...........................................................................................................................................................43 INTRODUCTION ...................................................................................................................................................44 5 TABLE OF CONTENTS MATERIALS AND METHODS ................................................................................................................................ 46 Study organism.............................................................................................................................................. 46 General methods ........................................................................................................................................... 47 Reproductive traits........................................................................................................................................ 48 Image proceeding and statistical analyses................................................................................................... 50 RESULTS.............................................................................................................................................................. 50 Intraspecific variation in reproductive traits............................................................................................... 50 Allometric relationships................................................................................................................................ 51 Reproductive character associations ........................................................................................................... 52 DISCUSSION ........................................................................................................................................................ 53 ACKNOWLEDGEMENTS ....................................................................................................................................... 56 CHAPTER III – EXPANDABLE SPERMATHECA INFLUENCES SPERM STORAGE IN THE SIMULTANEOUSLY HERMAPHRODITIC LAND SNAIL ARIANTA ARBUSTORUM........................ 57 ABSTRACT........................................................................................................................................................... 57 INTRODUCTION ................................................................................................................................................... 58 MATERIALS AND METHODS ................................................................................................................................ 60 RESULTS.............................................................................................................................................................. 63 Spermatheca size in relation to sperm storage ............................................................................................ 63 Spermatophore volume and sperm number.................................................................................................. 65 DISCUSSION ........................................................................................................................................................ 66 ACKNOWLEDGEMENTS ....................................................................................................................................... 69 CHAPTER IV – BURSA TRACT DIVERTICULUM IN THE HERMAPHRODITIC LAND SNAIL ARIANTA ARBUSTORUM (STYLOMMATOPHORA: HELICIDAE): MORPHOLOGY, FUNCTION, AND EVOLUTIONARY IMPLICATIONS.............................................................................. 71 ABSTRACT........................................................................................................................................................... 71 INTRODUCTION ................................................................................................................................................... 72 MATERIALS AND METHODS................................................................................................................................ 74 Animals .......................................................................................................................................................... 74 Histology and morphometry ........................................................................................................................