ABSTRACT
The proximal centriole is located at the base of the nucleus and is orientated at a right angle to the distal centriole. The distal centriole lies in the long axis of the spermatozoon and forms the basal body of the axoneme. The mitochondria of the midpiece are located at the base of the nucleus, around the tapered point, and posteriorly to the level of the distal centriole. Numerous vacuoles and cytoplasm are also present within the midpiece. The relatively small and spherical to oval mitochondria are scattered throughout the midpiece. Auxiliary microtubules are present within the tail region. The numerous microtubules are the same diameter as those of the axoneme and occupy most of the cytoplasm surrounding the axoneme.
