Reproductive biology of animal models includes biological aspects of reproduction in domestic and laboratory animal models as well as non-human primates and non-mammalian species with reference to humans which is of interest to a large group of investigators, students, clinicians, and numerous others including established investigators or newcomers to the field. The book will include the most commonly used animal models such as mouse, rat, pig, sheep, bovine, cat, dog, horse, non-human primates, and the zebrafish, amphibian, Drosophila, C elegans, and sea urchin models. These animals are either used for basic research on reproduction or as models for humans. Some, such as the sea urchin and mice, have been used as classic models for several decades to study cellular and molecular processes that are not easily performed in mammalian systems. We will include full chapters on non-human primates with reference to human reproduction that has become of significant interest, as in vitro fertilization (IVF) is being applied increasingly, and as reproductive disorders are becoming more and more recognized as causes for infertility that may be overcome through specific assisted reproductive technologies. Differences exist in the reproductive systems of different animal species that will be addressed in the different chapters. Cross-species information is important to further advance the field and address in vitro fertilization for dogs and horses that still face more difficulties than other animal species and are of interest to reproductive scientists.