The ovary of the bignose fanskate Sympterygia acuta Garman, 1877 (Chondrichthyes, Rajidae) in the Bahía Blanca estuary, Argentina: morphology and reproductive features

Abstract

Chondrichthyes have become an important economic resource in recent years. In spite of this importance, there is little knowledge about their reproductive biology, especially of species from the south-western Atlantic. In this work, we study the morphology and histology of the ovary of Sympterygia acuta. The results show that oogonia were present only in the immature females (stage I of maturity scale), whereas specimens in stages II and III of maturity displayed oocytes in all developmental steps. The most important histological features that vary throughout oocyte development are the presence or absence of yolk, the number of types and layers of follicular cells and the degree of development of the thecae. Follicular cells are, at least, of two different types. Finally, a new point of view for the determination of maturity stages in the field based on the size of follicles is discussed.

Reproductive biology of the skates Sympterygia acuta Garman, 1877 and S. bonapartii Müller & Henle, 1841 (Chondrichthyes: Rajoidei) in south Brazil

“…The analysis performed by Díaz Andrade et al (2009) in females of S. acuta, in turn, revealed that, at histological level, vitellogenesis would start at 0.55 cm, a size again similar to the obtained in the present study, where vitellogenesis was macroscopically detected from follicles with diameters of 0.6 cm onward.…”

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

“…This pattern is also observed in other batoids (Prisco et al 2002). The presence of different follicular cells has also been reported in other Rajids (Díaz Andrade et al, 2009Hamlett et al, 1999;Prisco et al, 2002). Moreover, Prisco et al (2002) have reported at least three different types of follicular cells in Torpedo marmorata, distinguishable by their ultraestructural features.…”

“…The presence of oogonia has also been recorded in other Chondrichthyans. 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).…”

Reproductive biology of the eyespot skate Atlantoraja cyclophora (Elasmobranchii: Arhynchobatidae) an endemic species of the Southwestern Atlantic Ocean (34ºS - 42ºS)

“…The increase of liver weight observed in larger females (>500 mm TL), suggests higher energy storage in females during maturation, in comparison to adult males. This is consistent with the fact that the liver actively participates in the synthesis of yolk precursors (Koob, Callard, 1999;Prisco et al, 2002;Díaz-Andrade et al, 2009). Sexual dimorphism in maximum length and size at maturity has been observed in many chondrichthyans (Mabragaña et al, 2002;Ungaro, 2004;McFarlane, King, 2006;Ebert et al, 2008;Colonello et al, 2016;Chierichetti et al, 2017).…”