Ovarian Folliculogenesis in the Smallnose Fanskate Sympterygia bonapartii (Müller & Henle, 1841) (Chondrichthyes, Rajidae)

Abstract

SUMMARY:Chondrichthyes have become an important economic resource in the last decades, with Argentina as one of the countries that exploits more sharks and skates, even at levels that exceed de limits of many species. However, there is a scarce knowledge of the reproductive biology of this group, particularly from species inhabiting the Southern hemisphere. This work shows the most relevant facts during folliculogenesis in Sympterygia bonapartii. Results show that germinal cells are present in immature and maturing females. The most important facts that vary along de follicular development are the number of types and layers of follicular cells, the establishment of thin projections from the follicular cells and the degree of development of the thecae. Follicular cells are, at least, of two different types and both of them emit projections that break through the zona pellucida. The outer theca shows signs of synthetic activity. Atretic follicles of different sizes are present in exemplars of all the reproductive stages. These results are discussed in a physiological and adaptive context.

Histological Remarks of the Uterus of Sympterygia acuta (Garman, 1877) and Sympterygia bonapartii (Müller & Henle, 1841) (Chondrichthyes; Rajidae)

“…The anatomical disposition of the uteri of Sympterygia acuta and S. bonapartii is consistent with that seen in all studied Chondrichthyes (Díaz-Andrade et al, 2011;Galíndez et al, 2010a;Hamlett & Hysell, 1998;.…”

Reproductive system of females of the Magdalena river endemic stingray Potamotrygon magdalenae: Anatomical and functional aspects

“…In these groups, the proliferative phase of oogenesis ends at birth; which is different from what it has been observed in teleosts, reptiles, and many amphibians (Lombardi, ). In other species of batoids such as Torpedo marmorata (Prisco et al, ), S. acuta (Díaz‐Andrade et al, ), and S. bonapartii (Díaz‐Andrade et al, ), oogonia in ovaries of newborn individuals have also been observed.…”

The Female Reproductive System of Zearaja chilensis (Guichenot, 1848) (Chondrichthyes, Rajidae): Gametogenesis and Microscopic Validation of Maturity Criteria

“…In some cases, the presence of these cells has been observed even in exemplars that were close to hatching size (Díaz-Andrade et al 2009). Likewise, this cell type may be present in maturing females (Díaz-Andrade et al, 2011;Galíndez et al, 2014). The reproductive potential of species rests, among other things, in the number of primordial germ cells that can be recruited as gametes.…”