Front Cover

Biology of Stress in Fish

Copyright Page

Contents

Contributors

Preface

1 The Concept of Stress in Fish

1 Introduction

1.1 What Is Stress?

1.1.1 Stress Definition

1.1.2 The Physiological Stress Response

1.1.3 Stress and Homeostasis

1.1.4 Stress and Energetics

1.2 Dynamics of the Stress Response and Effects on Performance

1.2.1 The Response of the Physiological Systems

1.2.2 Acute, Chronic, and Multiple Stressors

1.3 Contemporary View of the GAS: Eustress versus Distress

1.4 Sensory Systems and Perception

1.5 Adaptation versus Nonadaptation Aspects of the Stress Response

1.6 Key Unknowns

References

2 Variation in the Neuroendocrine Stress Response

1 Introduction

2 Ontogeny of the Teleost Stress Response

3 Neuronal Substrate for Stress and Variation in Stress Responses

4 Divergent Stress Coping Styles, Animal Personalities, and Behavioral Syndromes

4.1 Conserved Physiology of Contrasting Stress Coping Styles

4.2 Stress, Neuroplasticity, and Coping Style

4.3 Genetic Basis for Individuality

4.4 Stress Coping and Life History

5 Agonistic Interactions: Stress and Aggression

6 Nutritional Factors Affecting Stress Responses

6.1 Amino Acids

6.2 Fatty Acids

7 Directions For Future Research

References

3 The Endocrinology of the Stress Response in Fish

1 Introduction

1.1 The Fish Forebrain

1.2 Stress

2 Stress and the Brain: The (Neuro-)Endocrine Hypothalamus

2.1 Fundamental Axes Interact

2.2 The CRF System

2.3 Ontogeny of the CRF System

2.4 Control Over the Pituitary Gland

2.5 CRF and Behavior

3 Stress and the Pituitary Gland

3.1 Adrenocorticotropic Hormone (ACTH)

3.2 Alpha-MSH

4 Stress and the Head Kidney

4.1 Catecholamine-Producing Cells

4.2 Steroid-Producing Cells

4.3 Communication Within the Head Kidney

4.4 Stress and Energy

5 Synthesis and Perspective

Acknowledgments

References

4 The Molecular Stress Response

1 Introduction

2 Molecular Regulation of the Hypothalamic-Pituitary-Interrenal (HPI) Axis

2.1 Hypothalamus

2.2 Pituitary

2.3 Head Kidney (Interrenal Tissue)

3 Genomic Cortisol Signaling

3.1 Glucocorticoid Receptor

3.2 Mineralocorticoid Receptor

4 Genomic Effects of Cortisol

4.1 Development of the Stress Axis

4.2 Molecular Adjustments During Stress

4.3 Cellular Adjustments

5 Significance of Molecular Responses

6 Approaches to Study Molecular Responses to Stress

6.1 Mechanistic Studies Using Targeted Mutagenesis

6.2 Epigenetic Regulation of Stress Response

6.2.1 DNA Methylation

6.2.2 Noncoding RNAs

7 Concluding Remarks and the Unknowns

References

5 Stress and Growth

1 Introduction

2 A Conceptual Framework for Growth

2.1 The Dynamic Energy Budget (DEB) Model for Growth

2.2 Myocyte Growth

2.2.1 Myoblast Differentiation and Fusion

2.2.2 Muscle Proteolysis

2.2.3 Regulation of Muscle Protein Dynamics

3 Stress Effect on Energy Available for Growth

3.1 Food Intake

3.2 Energy Substrate Absorption at the Gut

3.3 Energy Demand for Maintenance

4 Stress Effects on Promoters of Muscle Formation

4.1 Stress Effects on Myogenesis

4.2 Stress Regulation of the GH-IGF Axis

5 Conclusion and Knowledge Gaps

References

6 Homeostatic Responses to Osmotic Stress

1 Introduction

1.1 Osmoregulation in Fishes

1.2 pH Regulation in Freshwater and Seawater

1.3 Cell Volume Regulation

2 Responses to Hyperosmotic Stress

2.1 Monovalent Ions as Stressors

2.2 Divalent Ions as Stressors

2.3 Involvement of Hormones

3 Responses to Hypoosmotic Stress

3.1 Ionic Compositions as Stressors

3.2 Low pH as Stressors

3.3 Involvement of Hormones

4 Stress Sensing to Homeostasis

4.1 Osmosensors

4.2 Signal Transduction from Sensors

4.3 Targets of Intracellular Signaling Cascade

5 Energy Metabolism in Response to Osmotic Stress

5.1 Oxygen Consumption

5.2 Metabolism Modifications

5.3 Metabolites Transport

6 Conclusions and Perspectives

References

7 The Stress and Stress Mitigation Effects of Exercise: Cardiovascular, Metabolic, and Skeletal Muscle Adjustments

1 Introduction

2 Physiological Demands of Swimming Exercise and the Stress Continuum

2.1 Introduction

2.2 Neuroendocrine Aspects of Stress and Exercise

2.3 Energy Metabolism During Stress and Exercise

2.3.1 Exercise Effects on Water and Ion Homeostasis

2.3.2 Muscle Activity and Locomotion

2.3.3 Energy Production and Utilization

2.3.3.1 Phosphagens

2.3.3.2 Glycolysis and Gluconeogenesis

2.3.3.3 Oxidative Phosphorylation

2.3.3.4 Measurements of Oxygen Consumption

2.4 Cardiovascular and Respiratory Adjustments to Stress and Exercise

2.4.1 Cardiovascular Adjustments

2.4.2 Respiratory Adjustments

2.5 Limits of Swimming Exercise and Stress

3 Physiological Adaptations to Swimming and Relevance to Stress

3.1 Introduction

3.2 Effects of Swim Training on the Cardiovascular System

3.3 Effects of Swim Training on Feeding and Energy Metabolism

3.3.1 Energy Sensing Mechanisms in Skeletal Muscle in Swimming Fish: AMPK

3.4 Effects of Swim Training on Skeletal Muscle Growth

3.4.1 Aerobic Swimming and Its Regulation of Skeletal Muscle Mass

3.4.2 Acquisition of an Aerobic Phenotype in Skeletal Muscle by Swim Training

3.4.3 Increased Aerobic Phenotype Is Associated with Improved Performance After Swim Training

3.5 Effects of Swim Training on Stress: Behavior, Health, and Welfare

3.5.1 Effects of Swim Training on Behavior and Stress

3.5.2 Effects on Swim Training on Disease Resistance

3.5.3 Effects on Swim Training on Stress and Fish Welfare

3.6 Summary, Future Perspectives, and Key Unknowns

References

8 Reproduction and Development

1 Introduction

2 Regulation of Reproduction

2.1 Patterns and Environmental Regulation of Reproduction

2.2 Endocrine Control of Reproduction

3 Effects of Stress on Reproduction

3.1 Effects on Reproductive Performance

3.2 Effects of Stress on the Reproductive Endocrine System

3.3 Thermal Stress: A Special Case?

3.4 Effects of Hypoxia

3.5 Stimulatory Effects of Stress on Reproduction

4 Mechanisms of Stress Action

4.1 The Role of Cortisol: In Vivo Protocols

4.2 The Role of Cortisol: In Vitro Protocols

4.3 Effects of Other Stress Factors

5 Stress Effects on Reproduction in Natural Environments

6 Future Directions

References

9 Cognition, Learning, and Behavior

1 How Stress Can Affect Behavior, and Vice Versa

2 Optimality, Preferences, and Decision-Making

3 Salmon as Model Species

4 Learning in Relation to Stress in Fishes

4.1 Learning, Plasticity, and Problem Solving

5 Some Critical Knowledge Gaps

Acknowledgments

References

10 Stress and Disease Resistance: Immune System and Immunoendocrine Interactions

1 Introduction

2 Effects of Stressors on the Immune Response

2.1 Suppressive Versus Enhancing Effects

2.2 Perception of Stress After Immune Stimulation: Systemic Versus Local Responses

2.3 Stress and the Cellular and Humoral Immune Response

3 Organization of the Immune Response Following Stress: The Neuroimmunoendocrine Connection and the Role of the Head Kidney

4 Effects of Hormones on the Immune System

4.1 Hypothalamic Hormones

4.2 Pituitary Hormones

4.3 Interrenal Hormones

4.3.1 Immune Modulation by the Hypothalamic-Sympathetic-Chromaffin Cell Axis

4.3.2 Immune Modulation by Corticosteroids

4.4 Receptor-Mediating Action of Cortisol in Fish Immunity During Stress Response

4.4.1 In Vivo Studies

4.4.2 In vitro Studies

4.5 Somatotropic Axis and Fish Immune System

5 Environmental Stressors and Fish Immunity

5.1 Environmental Salinity

5.2 Temperature and Seasonality

6 Future Directions

References

11 Stress Indicators in Fish

1 Why Do We Measure Stress?

2 Quantifying Stress

3 Specific Measures of Fish Stress

3.1 Cellular and Molecular Indicators

3.2 Primary and Secondary Physiological Indicators

3.3 Whole-Organism Indicators

4 Considerations for Measuring and Interpreting Stress

4.1 Interspecific Differences

4.2 Intraspecific Differences

4.3 Context-Specific Differences

4.4 Stressor Severity

4.5 Field Versus Laboratory

4.6 Temporal Aspects

5 From Individual Indicators to Ecosystem Health

6 Stress Indicators of the Future

7 Conclusion

References

12 Stress Management and Welfare

1 Introduction

1.1 Defining Welfare

2 Managing Stress in Fish

2.1 Considerations for Care of Wild Fish in Captivity

2.2 The Impact of Psychological Stress

2.3 Controlling and Preparing for Stress

3 The Impact of Stress on Fish Welfare

3.1 Stress in Fisheries

3.2 Stress in Aquaculture

3.3 Stress in Recreational Fishing

3.4 Stress in Ornamental Fish

3.5 Stress in Research Within a Laboratory Context

3.6 Stress and Welfare in Wild Fish

3.6.1 Fish Surveys

3.6.2 Holding Conditions

3.6.3 Tagging and Invasive Procedures

3.6.4 Dams and Other Barriers

3.6.5 Aquaculture and the Impact on Wild Fish

3.7 Surgery and Anesthesia

4 Conclusions and Future Directions

References

13 Stress in Fish as Model Organisms

1 Introduction

2 Indicators of Stress in Laboratory Fish

3 Factors Impacting Stress in Laboratory Fish Handling

4 Housing

4.1 Density

4.2 Enrichment

4.3 Light/Dark Cycle

5 Feeding and Stress

6 Sex and Hierarchies

7 Sex Determination and Reversal

8 Stress, Cortisol, and Reproduction

9 Anesthetics

10 Underlying Diseases

11 Consistency

12 Conclusion and Key Unknowns

References

Index

Other Volumes in The Fish Physiology Series

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