PRECOPULATORY MATE GUARDING BEHAVIOR INCLAM SHRIMP: A CASE OF INTERSEXUAL CONFLICT A dissertation submitted to Kent State University in cooperation with The University of Akron in partial fulfillment of the requirements for the degree of Doctor of Philosophy by Chiara Benvenuto December 2008 i Dissertation written by Chiara Benvenuto B.Sc./M.Sc. (Laurea), Università degli Studi di Firenze, 1999 Ph.D., Kent State University, 2008 Approved by ____________________________, Chair, Doctoral Dissertation Committee Dr. Stephen C. Weeks ____________________________, Co-advisor, Doctoral Dissertation Committee Dr. Walter R. Hoeh ____________________________, Members, Doctoral Dissertation Committee Dr. Mark W. Kershner ____________________________, Dr. Lisa E. Park ____________________________, Dr. David C. Riccio Accepted by ____________________________, Chair, Department of Biological Sciences Dr. James L. Blank ____________________________, Dean, College of Arts and Sciences Dr. John R. D. Stalvey i TABLE OF CONTENTS LIST OF FIGURES............................................................................................................ vi LIST OF TABLES ...........................................................................................................viii ACKNOWLEDGMENTS..................................................................................................ix CHAPTERS I. GENERAL INTRODUCTION ..................................................................................... 1 Sexual selection and sexual conflict ................................................................1 Components of sexual conflict......................................................................... 5 The outcome of the war of the sexes: who wins? ............................................9 Testing sexual conflict ................................................................................... 13 Mate guarding and sexual conflict.................................................................20 Precopulatory mate guarding in Crustacea ....................................................22 Models of mate guarding ............................................................................... 25 Parker’s model (1974)........................................................................26 Wickler and Seibt’s models (1979-1981) ..........................................27 Grafen & Ridley’s model (1983) .......................................................28 Hunte, Myers, and Doyle’s model (1985)..........................................29 Yamamura’s model (1987) ................................................................30 Elwood and Dick’s model (1990) ......................................................30 Jormalainen, Tuomi, and Yamamura’s model (1994) .......................31 ii Yamamura and Jormalainen’s model (1996).....................................32 Jormalainen’s model (1998)...............................................................32 Härdling, Jormalainen, and Tuomi’s model (1999)...........................35 Härdling, Kokko, and Elwood (2004)................................................36 An empirical approach: the economics of mate guarding..............................37 Mate guarding in an androdioecious species: how hermaphrodites fit into the equation ........................................................................................ 40 The study system............................................................................................ 42 Overview of research obJectives....................................................................43 II. MATE RECEPTIVITY ASSESSMENT AND PRECOPULATORY MATE GUARDING BEHAVIOR IN THE CLAM SHRIMP EULIMNADIA TEXANA ...... 46 Abstract ..........................................................................................................46 Introduction....................................................................................................47 Materials and methods ................................................................................... 54 ProJect 1 - Tracking focal animals .....................................................56 ProJect 2 - Molting hormone as a soluble cue....................................57 ProJect 3 - Molting hormone as a direct contact cue..........................58 Results............................................................................................................61 ProJect 1 - Tracking............................................................................61 ProJect 2 - Molting hormone as a soluble cue....................................63 ProJect 3 - Molting hormone as a direct contact cue..........................64 iii Discussion ......................................................................................................70 Acknowledgements........................................................................................ 79 III. INTERSEXUAL CONFLICT DURING MATE GUARDING INTHE ANDRODIOECIOUS CLAM SHRIMP EULIMNADIA TEXANA ...........................80 Abstract ..........................................................................................................80 Introduction....................................................................................................81 Materials and methods ................................................................................... 85 Mate guarding costs ...........................................................................85 The effect of size................................................................................86 Compromised and optimal guarding times ........................................87 Results............................................................................................................90 Mate guarding costs ...........................................................................90 The effect of size................................................................................92 Compromised and Optimal Guarding Time.......................................93 Discussion ......................................................................................................96 Acknowledgements...................................................................................... 105 IV. MATE GUARDING BEHAVIOR INCLAM SHRIMP: THE INFLUENCE OF MATING SYSTEM ONINTERSEXUAL CONFLICT.........................................106 Abstract ........................................................................................................106 Introduction..................................................................................................107 Materials and methods ................................................................................. 112 iv Rearing in the laboratory..................................................................112 Mate guarding in Limnadia badia .................................................... 113 Compromised mate guarding time across species ...........................114 Statistical analyses ...........................................................................114 Results..........................................................................................................115 Mate guarding in Limnadia badia .................................................... 115 Compromised mate guarding time across species ...........................117 Discussion ....................................................................................................120 Acknowledgements...................................................................................... 128 V. MATE GUARDING BEHAVIOR INCLAM SHRIMP: A FIELD APPROACH.129 Abstract ........................................................................................................129 Introduction..................................................................................................130 Materials and methods ................................................................................. 135 Results..........................................................................................................140 Mate guarding time ..........................................................................140 Male time budgets............................................................................145 Male takeovers .................................................................................147 Discussion ....................................................................................................148 Acknowledgements...................................................................................... 154 VI. GENERAL DISCUSSIONAND CONCLUSIONS ..............................................156 REFERENCES .............................................................................................................164 v LIST OF FIGURES Figure 1.1 Variation in maximum acceptable conflict costs for males and females in relation to time (female molt cycle)......................................... 33 Figure 2.1 Scheme of the arena used in ProJect 1 and 2............................................. 55 Figure 2.2 Mean distance from origin of coordinates (control) and the chamber with opposite sex (stimulus)................................................. 62 Figure 2.3 Total distance traveled by each sex in absence (control) and presence of other clam shrimp (stimulus) ................................................. 63 Figure 2.4 Number of mate guarding attempts performed