This book addresses the growing needs in deciphering the biological processes associated with fish reproduction, in view of the growth of aquaculture and the dwindling natural stocks of commercially important fish. It presents a comprehensive overview on egg production in fish, from the standpoint of the oocyte. With this view in mind, the book includes chapters on oocyte development (oogenesis), hormonal regulation and hormone receptors, formation of the egg envelopes, growth, accumulation of nutrients and maternal transcripts, maturation, hydration, ovulation and fertilization. A special emphasis is placed on using state-of-the-art tools including electron microscopy for discerning the ultra-structure of the follicle and genomic/proteomic tools to fully understand biological basis of fish reproduction. Studies on promoting oocyte maturation, ovulation and spawning in farmed fish and preservation of fish oocytes at low temperatures are also included. The book will appeal to University lecturers, students, research scientists and those associated with culture of fish in freshwater or marine aquaculture.