Ovaprim is injected into the fish during the spawning season to promote and facilitate reproduction of many species of fish. Using OVAPRIM, time to ovulation following injection is highly predictable, with high egg fertility and viability. Ovaprim can be used in any population of fish during or shortly before the spawning season. When used within a spawning population, Ovaprim will compress the spawning season of cold water fishes to within 1-2 weeks post-injection. For warm water fishes, ovulation times can be shortened to 24-48 hours. There is no substitute for well-described broodstock performance and the best results for using Ovaprim are in stocks with a recorded spawning history.