This book offers a detailed exploration of finfish and shellfish health in the first section. It covers health examination techniques for finfish, necropsy and sample collection, microbiology diagnosis, bacterial isolation and identification, and the preparation of subculture plates. Additionally, the health examination of shrimp and molecular technology are also discussed.The second section of the book focuses on water quality in aquaculture ponds, including pH estimation, ammonia nitrogen and nitrite nitrogen analysis, and dissolved oxygen measurement.The third section provides an overview of small-scale aquaculture systems. This book serves as an innovative academic guide for students, faculty, and farmers, aiming to enhance fish production, improve food security, and support livelihoods.