Providing a broad and readable overview of the subject, this updated fourth edition of Aquaculture: An Introductory Text covers issues associated with sustainable aquaculture development, culture systems, hatchery methods, nutrition and feeding of aquaculture species, reproductive strategies, harvesting, and many other topics. While its main focus is on the culture of fish, molluscs and crustaceans for food, the book also covers other forms of aquaculture, such as the production of seaweeds, recreational fish and ornamental species, as well as live foods, such as algae and rotifers that are used to feed larval shrimp and marine fish.Thoroughly updated and revised, this essential textbook now includes: Increased coverage of open-ocean cage culture and sea lice issues with salmon culture; Coverage of the significant progress made in nutrition, including the move away from fishmeal as protein and fish oil as lipids in feed; Information on biofloc technology uses, predictive impacts of climate change, probiotics, and the impact of COVID-19 on the aquaculture community; Updated aquaculture production statistics and lists of approved anaesthetics. Aquaculture remains one of the most rapidly growing agricultural disciplines, and this book remains an essential resource for all students of aquaculture and related disciplines.