Aside from their immense importance in intensive commercial aquaculture, teleost fish are vital laboratory animals and are widely used by reproductive physiologists as model species. Over recent years, the control of fertility in commercially-important fish has become a subject of great economic importance in terms of manipulating valuable fisheries resources by adopting broodstock management strategies appropriate to the reproductive traits of the species concerned. This book, with chapters written by leading authorities, reflects the theoretical and practical importance of studies concerning the reproductive physiology of male broodfish. Significant advances and future trends in global research in fish spermatology are presented and discussed.