Spermatid are one of the intermediate stages during the formation of fully developed sperm cells called spermatozoa. The process by which spermatozoa are produce is called spermatogenesis. It starts with spermatogonium, or male germ cells produced in the testes. These diploid cells divide via mitosis to produce two diploid cells called primary spermatocytes. These primary spermatocytes then undergo meiosis I to produce secondary spermatocytes followed by meiosis II to produce four haploid cells called spermatid. After a maturation process called spermiogenesis, the spermatid become fully matured spermatozoa cells. These fully matured cells are the male gametes that are released from the penis during sexual reproduction.