ABSTRACT
Within the basal nuclear fossa lies the proximal centriole which is surrounded by a small amount of pericentriolar material that connects it to the nuclear fossa and distal centriole. The proximal centriole is orientated at approximately 85° to the long axis of the spermatozoon and at a right angle to the distal centriole which forms the basal body of the axoneme. The axial fiber extends anteriorly into the neck region to the basal most point of the nucleus. A short mitochondrial collar, containing scattered mitochondria, cytoplasm, electron dense granules, and the occasional vacuole, surrounds the anterior portion of the tail but is separated from it by a gap, the cytoplasmic canal. This collar is attached only to the centriolar/neck region of the spermatozoon and the cytoplasmic canal extends posteriorly from the level of the base of the distal centriole. The mitochondria have well-developed linear cristae and are of similar shape and size, being generally spherical.
