The Reproductive Biology of the Chelonia

1 Introduction.- 1.1 Phylogeny.- 1.1.1 The Chelonian Bauplan.- 1.1.2 Fossil History and Evolution.- 1.1.3 Systematics and Biogeography.- 1.1.4 Body Size.- 1.2 Chelonian Reproductive Traits Compared with Other Reptiles.- 1.3 Anatomy of the Sexual Organs.- 1.3.1 Males.- 1.3.2 Females.- 1.4 Secondary Sexual Characteristics.- 2 Methods to Study Reproduction.- 2.1 Radiography.- 2.2 Ultra-sound Scanning.- 2.3 Laparoscopy and Biopsies.- 2.4 Blood Sampling.- 2.5 Considerations Regarding Captive Maintenance.- 3 Gonadal Cycles and Gamete Production.- 3.1 Sexual Maturity.- 3.2 Ovarian Cycle and Egg Production.- 3.2.1 Oogenesis and Folliculogenesis.- 3.2.2 Vitellogenesis.- 3.2.3 Oocyte Maturation and Ovulation.- 3.2.4 Luteal Phase.- 3.2.5 Oviducal Period.- 3.2.6 Regression and Follicular Atresia.- 3.3 Testicular Cycle and Sperm Production.- 3.3.1 Germinal Quiescence.- 3.3.2 Gonial Proliferation.- 3.3.3 Spermatocytogenesis.- 3.3.4 Spermiogenesis.- 3.3.5 Spermiation.- 3.3.6 Maturation and Storage of Sperm in the Epididymis.- 3.4 Accessory Secretions and Insemination.- 3.5 Sperm Storage in the Female Genital Tract.- 4 Reproductive Behaviour.- 4.1 Migration.- 4.2 Sexual Behaviour.- 4.2.1 Timing of Mating.- 4.2.2 Finding a Partner.- 4.2.3 Courtship and Copulation.- 4.2.4 Sexual Selection and Sexual Size Dimorphism.- 4.3 Nesting.- 4.3.1 Nesting Area and Selection of Nest Site.- 4.3.2 Conditions for Nesting.- 4.3.3 Preparation of Nest Site.- 4.3.4 Digging the Nest Hole.- 4.3.5 Oviposition.- 4.3.6 Covering the Nest.- 4.3.7 Nest Guarding.- 4.4 Emergence from the Nest.- 5 Reproductive Cycles and Environment.- 5.1 Temperate Zone.- 5.2 Tropical and Subtropical Zone.- 5.3 Multi-Year Reproductive Cycles.- 5.4 Unpredictable Habitats.- 5.5 Conclusions.- 6 Control of Reproduction.- 6.1 Exogenous Factors.- 6.1.1 Temperature and Photoperiod.- 6.1.2 Water Levels, Rain and Moisture.- 6.1.3 Food Availability.- 6.1.4 Social Factors and Population Density.- 6.2 Endogenous Timing Mechanisms.- 6.3 Effects of Stress on Reproduction.- 6.4 Conclusions.- 7 Hormones and Reproduction.- 7.1 Gonadal Steroids.- 7.1.1 Males.- 7.1.2 Females.- 7.2 Gonadotropins.- 7.3 Gonadotropin-Releasing Hormone.- 7.4 Pineal Hormones.- 7.5 Other Hormones.- 7.6 Hormones and Behaviour.- 7.7 Conclusions.- 8 Eggs and Embryonic Development.- 8.1 Egg Characteristics.- 8.1.1 Eggshell.- 8.1.2 Egg Contents.- 8.2 Development and Hatching.- 8.2.1 Development Rates and Incubation Times.- 8.2.2 Descriptive Embryology.- 8.2.3 Pipping and Hatching.- 8.3 Sex Determination.- 8.4 Effect of Incubation Environment on Neonates.- 9 Reproductive Patterns and Life History.- 9.1 Resource Allocation.- 9.1.1 Growth and Maturity.- 9.1.2 Egg Size, Clutch Size and Clutch Frequency.- 9.1.3 Reproductive Effort and Cost of Reproduction.- 9.1.4 Mortality, Longevity and Ageing.- 9.1.5 Somatic Repair.- 9.2 Population Structure and Dynamics.- 10 Threats, Reproduction and Conservation.- 10.1 Environmental Degradation.- 10.1.1 Case Study: Pseudemydura umbrina.- 10.2 Exploitation.- 10.2.1 Case Study: Erymnochelys madagascariensis.- 10.3 Conservation Strategies.- 10.3.1 Conservation of Wild Populations.- 10.3.2 Sustainable Use.- 10.3.3 Conservation in Captivity.- 10.3.4 Case Study: Pseudemydura umbrina.- 10.3.5 Case Study: Erymnochelys madagascariensis.- 10.4 Commercial Captive Breeding Operations.- 10.5 Risk Minimisation in Assessing Reproduction in Live Chelonians.- 10.5.1 Risks and Limitations of Currently Used Methods.- 10.5.2 Routine Screening of Reproductive Condition.- 11 Conclusions and Outlook.- References.- Systematic Index.