This book provides an extensive and practice-oriented overview of fish diseases, pathogen diagnostics, and laboratory techniques used in aquaculture health management. It is an essential resource for students, aquatic veterinarians, aquaculture professionals, researchers, and diagnostic laboratory personnel.

Beginning with the classification of fish pathogens—bacterial, viral, fungal, parasitic, and non-infectious—the book emphasizes the importance of early disease diagnosis and biosafety practices. It offers detailed procedures for sample collection, preservation, and transportation, both from live and dead fish specimens.

Core chapters explain bacterial culture methods, biochemical identification, hematological and histopathological analysis, and wet mount techniques. A major section is devoted to molecular diagnostics, including PCR, qPCR, ELISA, and DNA sequencing, along with field-level detection tools and diagnostic kits.

It also addresses the interpretation of lab reports, outbreak mapping, and surveillance standards, guided by national (ICAR, MPEDA) and international (OIE/WOAH) protocols.

1. Introduction to Fish Pathology and Pathogen Types

2. Biosafety and Good Laboratory Practices (GLP)

3. Collection, Transportation, and Preservation of Samples

4. Bacterial Culture Techniques

5. Biochemical Tests for Bacterial Identification

6. Fungal and Parasitic Pathogen Detection

7. Blood Collection and Hematological Tests

8. Histopathological Techniques

9. Cytological and Wet Mount Techniques

10. Polymerase Chain Reaction (PCR) for Pathogen Detection

11. ELISA and Serological Techniques

12. Advanced Molecular Techniques

13. Diagnostic Kits and Field-Level Detection

14. Interpretation of Lab Reports and Disease Surveillance

15. National and International Diagnostic Standards