CONTENTS: UNIT - I: 1. INTRODUCTION AND HISTORY OF PHYSIOLOGY: 2. WATER: THE BIOLOGICAL MEDIUM AND ITS ECOLOGICAL SIGNIFICANCE: 2.1. Origin of Life in Aquatic Medium, 2.2. General Properties of Water, 2.3. Physical, Chemical and Biological Factors/Properties of Water, 2.4. The Hydrological Cycle, 2.5. Significance of Water in Living Systems, 3. GAS EXCHANGE: 3.1. Overview of Gas Exchange, 3.2. Respiration in Aquatic Animals, 3.3. Respiration in Teleost and Elasmobranch, 3.4. Accessory Respiratory Organs in Finfish, 3.5. Influence of environmental factors on oxygen consumption in fish, 3.6. Respiration in Shellfishes : Overview, 3.7. Respiratory organs and ventilation in crustaceans, 3.8. Respiratory organs and ventilation in molluscs, 3.9. Physiology of gas exchange in fish, 4. MUSCLE PHYSIOLOGY: 4.1. Structure of Various Muscles, 4.2. Fish: Muscle Physiology, 4.3. Muscle types in shellfish: Overview, 4.4. Molluscan Catch Muscle, 4.5. Crustacean Muscle: Physiology, 4.6. Interesting Facts of Fish Muscular System, . UNIT - II: 5. CIRCULATION: 5.1. Circulatory Physiology in Animals, 5.2. Circulatory Physiology in Primitive Vertebrates, 5.3. Circulatory Physiology of Teleost & Elasmobranch, 5.4. Blood and Circulation in Fishes, 5.5. Physiology of circulation in crustaceans, 5.6. Physiology of circulation in molluscs, 6. PHYSIOLOGY OF EXCRETION: 6.1 Overview of Excretory Physiology in Fishes, 6.2. Anatomy of the kidney of fishes, 6.3. Significance of Kidney in Fishes, 6.4. Excretory stratagies in fish, 6.5. Excretory Physiology of Crustaceans, 6.6. Excretory Physiology of Molluscs, 7. OSMOREGULATION: 7.1. Osmoregulatory strategies in fishes, 7.2. Osmoregulation in Crustaceans, 7.3. Osmoregulation in Molluscs, 8. SENSE ORGANS: 8.1. Sense Organs in FinFishes, 8.2. Sensory Organs in Crustaceans, 8.3. Sensory Organs in Molluscs, UNIT - III: 9. DIGESTIVE FISH PHYSIOLOGY: 9.1. Overview of Digestive Fish Physiology, 9.2. Digestive Fluids and Enzymes in Fishes, 9.3. Digestion and Absorption in Fishes, 9.4. Digestive Physiology of Shellfish, 9.5. Digestive Enzymes and Regulation in Shellfish, 10. ENERGY AND NUTRIENT STATUS OF AQUATIC ORGANISMS METABOLIC PATHWAYS, NITROGEN BALANCE, AND UTILIZATION: 10.1. Energy and Nutrient Status of Food, 10.2. Nitrogen Balance – Ammonia Production, 10.3. Metabolism, 10.4. Energy Utilization, UNIT - IV: 11. REPRODUCTIVE PHYSIOLOGY: 11.1. Overview of Reproductive Physiology, 11.2. Reproductive Strategies in Fish, 11.3. Oogenisis and Oocyte Development in Fishes, 11.4. Spermatogenisis in Fishes, 11.5. Endocrine Regulation of Reproduction, 11.6. Reproductive physiology of crustaceans, 11.7. Endocrine and Neuroendocrine Regulation of Reproduction and Growth in Crustaceans, 12. ENDOCRINE GLANDS: 12.1. Endocrine System of Teleosts, 12.2. Endocrine System of Dipnoi and Elasmobranchs & Agnathas, 12.3. Endocrine System of Crustaceans, 12.4. Endocrine System of Molluscs, UNIT - V: 13. STRESS PHYSIOLOGY: 13.1. Definition: Stress, 13.2. Stress related physiological changes, 13.3. Types/classification of stressors, 13.4. Stress and defense mechanism, 14. EFFECT OF ENVIRONMENTAL FACTORS ON THE PHYSIOLOGY OF FINFISH AND SHELLFISH: 14.1. Temperature, 14.2. Oxygen Availability (Dissolved Oxygen – DO), 14.3. Salinity, 14.4. pH and Water Chemistry, 14.5. Light (Photoperiod and Intensity), 11.6. Additional Environmental Factors Affecting Physiology of Finfish and Shellfish, 11.7 Conclusion.