Stereom differentiation in sea urchin spines under special consideration as a model for a new impact protective system Dissertation zur Erlangung des Grades eines Doktors der Naturwissenschaften der Geowissenschaftlichen Fakultät der Eberhard Karls Universität Tübingen vorgelegt von Jan Nils Großmann aus Frankfurt/Main 2010 Tag der mündlichen Prüfung: 30.09.2010 Dekan: Prof. Dr. Peter Grathwohl 1. Berichterstatter: Prof. Dr. James H. Nebelsick 2. Berichterstatter: Prof. Dr. Oliver Betz Table of contents Overview: Aim of the project .................................................................................................... 1 Chapter 1: The world of echinoderms ....................................................................................... 4 Abstract .................................................................................................................................. 4 1. Introduction & general features ......................................................................................... 4 2. General development of echinoderms ............................................................................... 5 3. Defence strategy of echinoderms ....................................................................................... 6 4. General morphology & body plan of sea urchins .............................................................. 6 5. General features of spines .................................................................................................. 9 6. General regeneration possibilities and growth of spines and plates ................................ 11 7. References ........................................................................................................................ 13 Chapter 2: Morphological differentiations in sea urchin spines ............................................. 19 Abstract ................................................................................................................................ 19 1. Introduction ..................................................................................................................... 19 1.1 Bionically inspired material based on the echinoderm skeleton ........................... 19 1.2 Sea urchins skeletal morphology ........................................................................... 20 1.2.1 Stereom in spines .................................................................................... 22 1.2.2 Morphology of the spine ......................................................................... 23 2. Materials & Methods ....................................................................................................... 24 2.1 Aquaria & technical equipment ............................................................................. 24 2.2 Sample preparation ................................................................................................ 27 2.3 SEM ....................................................................................................................... 27 2.4 Critical point drying .............................................................................................. 28 2.5 Measurement of the stereom morphology ............................................................. 28 3. Results ............................................................................................................................. 31 3.1 Cidaroid spines: Surface morphology ................................................................... 32 3.1.1 Plococidaris verticillata ......................................................................... 33 3.1.2 Plococidaris verticillata: Medulla .......................................................... 35 3.1.3 Plococidaris verticillata: Radiating layer ............................................... 38 3.2 Phyllacanthus imperialis ....................................................................................... 40 3.2.1 Phyllacanthus imperialis: Oral spines .................................................... 40 3.2.2 Phyllacanthus imperialis: Medulla ......................................................... 42 3.2.3 Phyllacanthus imperialis: Radiating layer .............................................. 45 3.2.4 Phyllacanthus imperialis spines (aboral): Medulla ................................ 48 3.2.5 Phyllacanthus imperialis spines (aboral): Radiating Layer .................... 51 3.3 Eucidaris metularia ............................................................................................... 53 3.3.1 Eucidaris metularia: Medulla ................................................................. 54 3.3.2 Eucidaris metularia: Radiating layer ...................................................... 57 3.4 Prionocidaris baculosa ......................................................................................... 59 3.4.1 Prionocidaris baculosa: Medulla ........................................................... 60 3.4.2 Prionocidaris baculosa: Radiating layer ................................................ 63 3.5 Spines of Echinoida: Surface morphology ............................................................ 66 3.5.1 Heterocentrotus mammillatus ................................................................. 66 3.5.2 Heterocentrotus mammillatus: Juvenile spine ........................................ 67 3.5.3 Heterocentrotus mammillatus spines (juvenile): Medulla ...................... 69 3.5.4 Heterocentrotus mammillatus spines (juvenile): Radiating Layer ......... 72 3.5.5 Heterocentrotus mammillatus spines (fully grown): Medulla ................ 75 3.5.6 Heterocentrotus mammillatus spines (fully grown): Radiating layer ..... 78 3.6 Stereom types and morphology ............................................................................. 81 3.7 Critical point drying .............................................................................................. 82 4. Discussion ........................................................................................................................ 85 5. Conclusion ....................................................................................................................... 87 6. References ........................................................................................................................ 88 7. Supplement ...................................................................................................................... 95 7.1 Aquaria assemblage ............................................................................................... 95 7.2 Scanning electron microscopy images .................................................................. 97 Chapter 3: Computer tomography of sea urchin spines ........................................................ 103 Abstract .............................................................................................................................. 103 1. Introduction ................................................................................................................... 103 2. Materials & Methods ..................................................................................................... 105 2.1 Materials .............................................................................................................. 105 2.1.1 X-ray Computer Tomography .............................................................. 105 2.2 Methods ............................................................................................................... 105 3. Results ........................................................................................................................... 106 3.1 Heterocentrotus mammillatus .............................................................................. 106 3.1.1 Heterocentrotus mammillatus: Aboral spines ....................................... 106 3.1.2 Heterocentrotus mammillatus: Oral spines ........................................... 110 3.2 Phyllacanthus imperialis ...................................................................................... 111 3.2.1 Phyllacanthus imperialis: Aboral spines ............................................... 111 3.2.2 Phyllacanthus imperialis: Oral spines ................................................... 112 3.3 Prionocidaris baculosa ........................................................................................ 114 4. Discussion ...................................................................................................................... 116 5. Conclusion ..................................................................................................................... 118 6. References....................................................................................................................... 119 Chapter 4: 3-point-bending-tests of sea urchin spines .......................................................... 124 Abstract .............................................................................................................................. 124 1. Introduction ................................................................................................................... 124 2. Materials & Methods ..................................................................................................... 127 2.1 Materials .............................................................................................................. 127