Whale sharks are the largest of all fishes, fascinating for comparative studies of all manner of biological fields, including functional anatomy, growth, metabolism, movement ecology, behavior and physiology. These gentle ocean giants have captured the interest of scientists and the imagination of the public, yet their future is uncertain. The conservation status of whale sharks was upgraded to Endangered on the IUCN Red List and the species faces a range of intense threats from human activities. Can these iconic living animals, who have survived for millions of years, survive us?

Written by the world’s leading experts in whale shark biology, ecology, and conservation, Whale Sharks: Biology, Ecology and Conservation is the first definitive volume about the world's biggest fish. Chapters include discussions of satellite-linked tags, used to track whale shark movements; genetic sequencing, to examine evolutionary adaptations; even the use of underwater ultrasound units to investigate the species’ reproduction. The editors hope that by collating what is known, they can make it easier for future researchers, conservationists, and resource managers to fill some of the remaining knowledge gaps, and provide the information they need to join the team.

As you work your way through this book, we hope that you will develop a sense of awe and marvel at all of our good fortune to share the ocean, and the planet, with this utterly extraordinary species.

Chapter 1 How and Why Is the Whale Shark the World’s Largest Fish? 1.1 Introduction 1.2 The Whale Shark Body Plan 1.3 Just How Big Is the Whale Shark? 1.4 How Big Is the Whale Shark Relative to Other Large Marine Animals? 1.5 Why Is the Whale Shark So Large? 1.6 Why Isn’t the Whale Shark Larger? 1.7 Can Size Save the Whale Shark? 1.8 Conclusions Acknowledgments References Chapter 2 Whale Shark Reproduction, Growth, and Demography 2.1 Introduction 2.2 Reproductive Mode and Embryonic Development 2.3 Reproductive Anatomy in the Whale Shark 2.3.1 Female Reproductive Anatomy and Maturity 2.3.2 Male Reproductive Anatomy and Maturity 2.4 Reproductive Cycle, Seasonality, and Behavior 2.4.1 Female Reproductive Cycle and Seasonality 2.4.2 Male Reproductive Cycle and Seasonality 2.5 Size at Birth and Early Growth 2.6 Estimating Age and Growth 2.6.1 Vertebral Aging 2.6.2 Field-Based Growth Estimates 2.7 Body Condition and Health Assessment 2.8 Population Productivity 2.8.1 Estimating Productivity 2.8.1.1 Annual Reproductive Output 2.8.1.2 Age at First Reproduction 2.8.1.3 Survivorship 2.8.2 Productivity Results 2.9 Conclusions Acknowledgments References Chapter 3 Whale Shark Sensory Biology and Neuroanatomy Introduction 3.2 Sensory Systems 3.2.1 Introduction 3.2.2 Hearing 3.2.3 Chemoreception 3.2.3.1 Olfaction (smell) 3.2.3.2 Gustation (taste) 3.2.4 Vision 3.2.5 Mechanoreception (touch) 3.2.6 Electroreception 3.3 The Brain and Its Implications for Behavior 3.3.1 Introduction 3.3.2 Anatomy 3.3.3 Neuroecology: Understanding the Neurological Basis of Behavior 3.3.3.1 Encephalization 3.3.3.2 Brain Organization 3.3.3.3 Ontogenetic Shifts: Does Brain Organization Change with Growth? 3.4 Summary and Future Directions Acknowledgments References Chapter 4 Parasites and Other Associates of Whale Sharks 4.1 Introduction 4.2 Microbial Symbionts 4.2.1 Viruses 4.2.2 Bacteria 4.2.3 Fungi 4.2.4 Protistan parasites 4.3 Metazoan Parasites 4.3.1 Copepoda 4.3.1.1 Pandarus rhincodonicus Norman, Newbound and Knott, 2000 4.3.1.2 Prosaetes rhinodontis (Wright, 1876) 4.3.1.3 Lepeophtheirus acutus Heegaard, 1943 4.3.2 Isopoda 4.3.2.1 Gnathia trimaculata Coetzee, Smit, Grutter and Davies, 2009 4.3.3 Platyhelminthes 4.3.3.1 Wenyonia rhincodonti Malhotra, Jaiswal, Singh, Capoor and Malhotra, 2011 4.3.3.2 Paronatrema boholana Eduardo, 2010 4.3.4 Hirudinea 4.4 Associates 4.4.1 Surfers and Drafters 4.4.2 Scratchers 4.4.3 Suckers 4.4.4 Shelterers 4.4.5 It’s Complicated 4.5 Conclusions Acknowledgments References Chapter 5 Genetic Population Structure of Whale Sharks 5.1 What Is a Population? 5.1.1 Why Population Structure Matters 5.1.2 Determining Population Structure 5.1.2.1 Field Studies of Populations 5.1.2.2 Biochemical and Genetic Analysis of Populations 5.1.2.3 Using Genetics to Study Wild Populations 5.1.2.4 Genetic Analysis of Whale Shark Populations 5.2 Genetic Markers for Population Analysis 5.2.1 Genetic Diversity and Differentiation 5.2.2 Mitochondrial DNA Analysis 5.2.3 Microsatellite Analysis 5.2.4 Visual Representations of Population Data 5.3 Population Analysis of Whale Sharks 5.3.1 Field Studies of Whale Shark Populations 5.3.2 Mitochondrial DNA Analysis of Whale Shark Populations 5.3.3 Microsatellite Analysis of Whale Shark Populations 5.3.4 Emerging Genetic Technologies 5.4 Conclusions from Whale Shark Genetic Analyses 5.5 Integrating Field and Genetic Studies of Population Structure 5.6 Genomic Analysis in Whale Sharks 5.7 Future Challenges in Whale Shark Population Analysis Acknowledgments Glossary References Chapter 6 Whale Shark Movements and Migrations 6.1 Introduction 6.2 Tracking Animals in the Ocean 6.3 Vertical Movements of Whale Sharks 6.4 Horizontal Movements of Whale Sharks 6.4.1 Case Study: Ningaloo Reef 6.4.2 Case Study: Galapagos 6.5 Climate Change 6.6 Future Perspectives Acknowledgments References Chapter 7 Population Ecology of Whale Sharks 7.1 Introduction 7.2 Identifying Individual Sharks 7.2.1 Photographic Identification 7.2.2 Citizen Science 7.2.3 Data Mining with Artificial Intelligence 7.3 Population Ecology 7.3.1 Constellations 7.3.2 Segregated Populations 7.3.3 Size Segregation 7.3.4 Sexual Segregation 7.3.5 Transit vs Feeding Areas 7.4 Life Cycle Hypothesis 7.4.1 “The Lost Years” 7.4.2 The Hungry Years 7.4.3 Open Water 7.5 Summary References Chapter 8 Whale Shark Foraging, Feeding, and Diet 8.1 Introduction 8.2 Foraging Strategies 8.2.1 Returning to Predictable Feeding Hotspots 8.2.2 Large-Scale Movements away from Feeding Hotspots 8.3 Senses Involved in Foraging and Feeding 8.4 Feeding Mechanics 8.5 Feeding Behaviors 8.5.1 Passive Feeding 8.5.2 Active Feeding 8.5.3 Stationary Feeding 8.5.4 Other Feeding Behaviors 8.6 Whale Shark Prey Species 8.6.1 Methods of Identifying Prey 8.6.2 Identified Prey Items 8.6.3 Size and Biomass 8.7 Potential Prey 8.7.1 Methods for Indirect Diet Analyses 8.7.2 Potential Prey Items 8.7.3 Caveats of Diet Reconstruction from Whale Shark Tissue Samples 8.8 Ecological Role of Whale Sharks 8.9 Summary References Chapter 9 Lessons from Care of Whale Sharks in Public Aquariums 9.1 Introduction 9.2 A Brief History of Whale Sharks in Public Aquariums 9.3 Habitat Design 9.4 Acquisition/Disposition Techniques 9.5 Behavior and Its Management 9.6 Veterinary Care 9.7 Diet, Feeding, and Nutrition 9.8 Growth and Reproduction 9.9 Conclusions Acknowledgments References Chapter 10 Whale Shark Tourism as an Incentive-Based Conservation Approach 10.1 Introduction 10.2 Global Assessment of Whale Shark Tourism 10.2.1 Wild Sites 10.2.2 Provisioned Sites 10.2.3 Seapen Tourism 10.2.4 Aquarium Tourism 10.3 Economic Valuation of Whale Shark Tourism 10.4 Whale Sharks and Ecotourism 10.4.1 Impacts of Tourism on Whale Sharks 10.4.2 Community Involvement 10.4.3 Building Environmental Awareness 10.4.4 Tourist Satisfaction 10.4.5 Is Whale Shark Tourism Ecotourism? 10.5 Management Challenges 10.6 Management Best Practices 10.6.1 Managing Impacts 10.6.2 Best Practices for Whale Shark Tourism 10.7 Conclusion References Chapter 11 Global Threats to Whale Sharks 11.1 Introduction 11.2 Why Are Whale Sharks in Danger? 11.3 Fisheries 11.3.1 Historical Catches 11.3.2 Commercial Fishing and International Trade 11.3.3 Bycatch in Tuna Fisheries 11.3.4 Bycatch in Coastal Net Fisheries 11.3.5 Can Whale Sharks be Fished Sustainably? 11.4 Boat Strikes 11.5 Tourism Interactions 11.5.1 Behavioral Change and Physical Impacts 11.5.2 Artificial Provisioning and Artisanal Captivity 11.6 Marine Pollution 11.7 Climate Change 11.8 Threat Classification 11.8.1 Energy Production and Mining 11.8.2 Transportation and Service Corridors 11.8.3 Biological Resource Use 11.8.4 Human Intrusions and Disturbance 11.8.5 Pollution 11.8.6 Climate Change and Severe Weather 11.8.7 Prioritization of Ongoing Threats 11.9 Conclusions References Chapter 12 Conservation of Whale Sharks 12.1 Introduction 12.1.1 A History of Concern 12.1.2 Contemporary Threats 12.1.3 The IUCN Red List of Threatened Species 12.2 International Legal and Management Frameworks 12.2.1 United Nations Convention on the Law of the Sea 12.2.2 Convention on the Conservation of Migratory Species of Wild Animals 12.2.3 Convention on International Trade in Endangered Species of Wild Fauna and Flora 12.2.4 Convention on Biological Diversity 12.2.5 FAO International Plan of Action for the Conservation and Management of Sharks 12.2.6 Regional Fisheries Management Organizations 12.3 National Legal Protections 12.3.1 Species Protection 12.3.2 Marine Protected Areas 12.4 Whale Sharks as Conservation Icons 12.4.1 Flagship Species 12.4.2 Umbrella Species 12.4.3 Key Biodiversity Areas 12.5 The Road to Recovery 12.5.1 The IUCN Green Status of Species 12.5.2 Building a Green Status Assessment 12.5.2.1 Whale Shark Distribution and Spatial Units 12.5.2.2 Contemporary Regional Red List Assessments 12.5.2.3 Western Indian Ocean 12.5.2.4 Southeast Asia 12.5.2.5 Eastern Pacific Ocean 12.5.2.6 Ecological Functionality 12.5.3 Species Recovery Score Calculation 12.5.4 Conservation Impact Metrics 12.5.4.1 Conservation Legacy 12.5.4.2 Conservation Dependence 12.5.4.3 Conservation Gain 12.5.4.4 Recovery Potential 12.6 Conservation Planning 12.6.1 Preparing a Conservation Plan 12.6.1.1 Threat Identification and Prioritization 12.6.2 Implementing the Plan 12.7 Looking Forward 12.7.1 Closing the Gaps in Existing Protections 12.7.2 ‘Big Data’ for Habitat-Based Conservation 12.7.3 Planning for Action 12.8 Conclusions References Chapter 13 Outstanding Questions in Whale Shark Research and Conservation 13.1 Introduction 13.2 What Is the Genomic Basis of Gigantism in Whale Sharks, and How Does That Relate to Planktivory and Endothermy? 13.3 How Often Do Whale Sharks Breed? 13.4 How Does the Whale Shark Sense Its Environment and How Are These Signals Processed in the Brain? 13.5 What Is the Nature of the Relationships of Different Species of Microbes, Parasites, and Fishes That Associate with Whale Sharks? 13.6 How Can We Apply Genetic and Genomic Methods to Definitively Identify Population Structure at a Global Scale? 13.7 How Can We Obtain Longer and More Detailed Movement Tracks? 13.8 What Drives Sexual Segregation in Constellations? 13.9 What Do Neonates, Adults, Females, and Transient Whale Sharks Feed on? 13.10 How Can We Take Advantage of Whale Sharks in Aquariums to Fill Knowledge Gaps? 13.11 How Can We Ensure That Whale Shark Tourism Develops Sustainably? 13.12 How Problematic Is Plastic Pollution for Whale Sharks? 13.13 How Can the Whale Shark’s Recovery Potential Be Improved? 13.14 Are Whale Sharks Still a Mysterious Species?