Fig. 14 in Spermatic characteristics and sperm evolution on the subfamily Stevardiinae (Ostariophysi: Characiformes: Characidae)

Fig. 14. Spermatozoa of Piabina argentea. A: Longitudinal section of spermatozoon. Note the position of the nucleus (n) in relation to the flagellar axis and to proximal (p) and distal (d) centrioles, the eccentric position of the double nuclear fossa (double arrow), the midpiece and the cytoplasmic canal (*) containing the initial segment of the flagellum (f). B: Detail of the centriolar complex. Note the position of the centrioles to one another. C-E: Cross sections at the middle of the nucleus (n) and at different levels of the strongly asymmetric midpiece exposing the lateral position of the centrioles, cytoplasmic canal (*), the flagellum (f), and the distribution of the few elongate mitochondria (m) accumulated in larger portion of the midpiece.