Piabina anhembi, da Silva & Kaefer, 2003

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 anhembi ( Fig. 13 A-K)

In the spermatozoon of Piabina anhembi the ovoid nucleus measures 1.94  m in the longitudinal axis and 1.64  m in the transverse axis. The surrounding strip of cytoplasm has no organelles ( Fig. 13A ). Nuclear rotation toward the flagellar axis was about 80 degrees ( Fig. 13A ). The midpiece has a conical shape, measures about 1.13  m in length and contains some large and slightly elongated mitochondria ( Fig. 13A ). The endomembrane system is composed of vesicles with different sizes. The smaller are sparse, whereas the larger ones are connected to one another and to the plasma membrane ( Fig. 13 B-K).

Figures

Fig. 13. Spermatozoa of Piabina anhembi. 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 position of the double nuclear fossa (double arrow), the midpiece and the cytoplasmic canal (*) containing the initial segment of the flagellum (f). B-C: Cross sections at different levels of the nucleus showing large vesicles (v) in the surrounding cytoplasmic layer and the lateral position of the centriole (c). E-K: Cross sections at different levels of the strongly asymmetric midpiece, from the base of the nucleus (n) to the midpiece end exposing the cytoplasmic canal (*), and of the flagellum (f), the distribution of the few elongate mitochondria (m) accumulated in larger portion of the midpiece, and a few vesicles peripherally distributed in the midpiece (v).