Spermiogenesis

At the beginning of the stage, the spermatid is a more or less circular cell containing a nucleus, Golgi apparatus, centriole and mitochondria; by the end of the process, it has radically transformed into an elongated spermatozoon, complete with a head, midpiece, and tail.

The mature spermatozoa are released from the protective Sertoli cells into the lumen of the seminiferous tubule and a process called spermiation then takes place, which removes the remaining unnecessary cytoplasm and organelles.

The non-motile spermatozoa are transported to the epididymis in testicular fluid secreted by the Sertoli cells, with the aid of peristaltic contraction.

However, transport of the mature spermatozoa through the remainder of the male reproductive system is achieved via muscle contraction rather than the spermatozoon's motility.

A glycoprotein coat over the acrosome prevents the sperm from fertilizing the egg prior to traveling through the male and female reproductive tracts.