Genetic Sex Differentiation in Fish

A comprehensive elucidation of sex differentiation gonochoric and hermaphroditic fishes, this book examines sex chromosomes and sex determining genes, through sex differentiation genes and steroid receptor genes and to stem cells and germ cells. It emphasizes the need to search for more than one sex determining gene residing on different chromosomes, traces the origin of hermaphrodites from secondary gonochores, and explains the conservation of homologous sex differentiation and steroid receptor genes among gonochores and hermaphrodites. The author highlihgts that the changes in the phenotypic morphotypes among gonochores is intrasexual but intersexual among hermaphrodites and identifies the optimal broodstock size, the appropriate candidate species for bait and food fishes and recognizes that the fishes do undergo menopause and reproductive senescence, which has an implication on the production of stem cells. He shows that the analysis of steriles and mutants has demonstrated the value of fishes as a system for genetic dissection of human development and diseases.