In this book you will find some studies on the spermatozoa of mullet (Mugil liza) and a brief review of gamete conservation methods applied to fish today. The studies cover topics such as: morphometric description of the spermatozoa and sperm concentration of wild and captive-born fish, analysis of the ideal salinity and pH standards for activating the motility of these gametes, and the results of keeping semen under refrigeration (4°C) for up to 96 hours with and without the use of sperm diluents.