Methods of sperm quality assessment in fish

Through expanding of aquaculture activities, considering of male gamete quality has been increased. Egg fertilization with better quality sperm samples might increase fertilization outputs among all criteria (Fertilization and hatching rates, survival and growth). The quality of gametes involving fertilization relies on extensive factors which could have specific and different effects among species. So, there are many definitions for sperm quality. According to the scientific and technological improvements, the methods for sperm quality assessment have been continuously renewed and assessed through new vision. Study of spermatozoa, is easier than the eggs because of their specific characteristics and ease of sampling and the views of its quality assessment have been developed. In current article, after mentioning to most important fish spermatozoa cellular and morphometric characteristics, the most valuable quality indices and some factors affect them, have been discussed. Respecting to all studies on these indices and quality improvements of each techniques, spermatozoa motility and fertilization indices, still have been recognized as the indices and most reliable and practical indicators for routine sperm quality assessment in fish.