Greg worked for a large wholesaler of ornamental fishes before joining the faculty at the NC State College of Veterinary Medicine in 1993, where he is Professor of Aquatic, Wildlife, and Zoological Medicine. He is a diplomate of the American and European Colleges of Zoological Medicine. He's authored or co-authored over 200 scientific articles, 30 book chapters, and edited or co-edited five veterinary textbooks.

Roy worked for a large ornamental fish farm before joining the University of Florida IFAS Tropical Aquaculture Laboratory in 1996. As Professor and Extension Veterinarian, he provides outreach, research, and educational programs in disease diagnostics and health management. He has authored numerous articles and book chapters, co-founded the American Association of Fish Veterinarians, and hosts the Aquariumania podcast on PetLifeRadio.

1. Aquarium Fish Families and Species. Common Groups. Popular Freshwater Ornamental Fishes. Popular Tropical Marine Ornamental Fishes. Popular Aquarium Non-Fish Species. Laws and Permits 2. Aquarium Systems and Water Quality. Important System Processes. Tank Essentials. Water Chemistry Reference Ranges. The Nitrogen Cycle in Aquarium and Pond Systems. Water Quality: Chemical Imbalances and Management. Tank and Water Tips. Salt Calculations for Common Volumes of Water 3. Nutrition and Diet. General Nutrient Requirements and Feed Ingredients. Macronutrients. Micronutrients. Additional Considerations. Amount 4. General Reproduction. Sexing Select Species/Groups. General Reproductive Strategies. General Notes on Tropical Fish Early Life Stages. Egg-Binding (Egg Retention/Dystocia) 5. Clinical Case Work Ups: Initial Considerations Examination 6. Ante-Mortem Diagnostics External Wet Mount Biopsies. Bacterial Culture - Non-Sacrificial. Blood Collection Techniques. Diagnostic Evaluation of Samples. Hematology 7. Imaging Radiography and Ultrasonography General Comments. Examples 8. Post-Mortem Evaluation. General Comments on Specimen Quality. Necropsy Supplies. Microbiology Supplies. Wet Mount Evaluation. Necropsy and Microbiology. Normal Fish Anatomy 9. Euthanasia, Anesthesia, and Sedation General Considerations for Euthanasia. Indicators of Death in Fish. Euthanasia Methods. Anesthesia and Sedation. Anesthesia Tips 10. Surgery Common Indications for Surgery. Fish Anesthesia Deliver System. Induction, Maintenance, and Monitoring. Fish Preparation. Surgical Tips 10. Infectious Diseases. General Management Considerations. Preventive Care: Vaccines. Parasitic Diseases of Aquarium Fish. Bacterial Diseases of Aquarium Fish. Viral Diseases of Aquarium Fish. Fungal Diseases of Aquarium Fish. Reportable Diseases. Zoonoses. 12. Common Medical Conditions. Fatty Liver Disease. Neoplasia. Buoyancy Problems (Swim Bladder "Disease"). Superficial Wounds. Signs Associated with Water Quality Problems. Head and Lateral Line Erosion Syndrome (HLLES) of Marine Fish. Ocular Diseases. Nutritional Diseases. Constipation. Behavioral Considerations 13. Health Certificates/Certificate of Veterinary Inspection 14. Drugs and Chemicals: Administration Methods and Formulary. Pre-treatment Considerations. Routes of Drug and Chemical Administration for Ornamental Fish. Drugs and Dosages. 15. Equipment and Supplies Checklist. Husbandry. Medical. Microbiology. Drugs and Other Compounds. Diagnostic Materials. 16. Material Resources. Products and Services. Water Chemistry Test Kits. Fish Drug Distributors. Other Informational Resources. References/Further Reading.