Ceratobranchia obtusirostris, Eigenmann, 1914

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 : 381

Ceratobranchia obtusirostris ( Fig. 7 A-D)

In the spermatozoa of Ceratobranchia obtusirostris the nucleus measures 1.3  m in the longitudinal axis and 1.1  m in the transverse axis. The surrounding strip of cytoplasm has no organelles ( Fig. 7A ). Nuclear rotation toward the flagellar axis was about 70 degrees ( Fig. 7 A-B). The midpiece has a conical shape, measures about 0.6  m in length, and contains some slightly elongate mitochondria ( Fig. 7 A-D). Information on the endomembrane system is not available, since the specimens of C. obtusirostris have been obtained from ichthyological collections and the gonads were not appropriately preserved for ultrastructural analysis.

Figures

Fig. 7. Spermatozoa of Ceratobranchia obtusirostris. A-B: Longitudinal sections of spermatozoa. Note the lateral 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 containing the endomembrane system (v) and the cytoplasmic canal (*) containing the initial segment of the flagellum (f). C-D: Cross sections at different levels of the nucleus (n) exposing the lateral position of the cytoplasmic canal (*) and flagellum (f), the distribution of the few elongate mitochondria (m) accumulated in larger portion of the midpiece.