Piabina argentea, Reinhardt, 1867

Baicere-Silva, Clarianna Martins, Ferreira, Katiane M., Malabarba, Luiz R., Benine, Ricardo C. & Quagio-Grassiotto, Irani, 2011, Spermatic characteristics and sperm evolution on the subfamily Stevardiinae (Ostariophysi: Characiformes: Characidae), Neotropical Ichthyology 9 (2), pp. 377-392 : 383

Piabina argentea ( Fig. 14 A-E)

In the spermatozoon of Piabina argentea the ovoid nucleus measures 1.52  m in the longitudinal axis and 1.2  m in the transverse axis. The surrounding strip of cytoplasm has no organelles ( Fig. 14A ). Nuclear rotation toward the flagellar axis was about 85 degrees ( Fig. 14A ). The midpiece has a conical shape, measures about 0.6  m in length and contains some elongate mitochondria ( Fig. 14A ,C-E). Information on the endomembrane system is not available, since the specimens of P. argentea have been obtained from ichthyological collections and the gonads were not appropriately preserved for ultrastructural analysis.

Figures

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.