Morphology and dynamics of testicular gametogenesis in Sympterygia bonapartii (Chondrichthyes, Rajidae)

MOYA, A. C.; DÍAZ ANDRADE, M. C.; GALÍNDEZ, E. J.

IHERINGIA. SéRIE ZOOLOGIA

FUNDACAO ZOOBOTANICA RIO GRANDE SUL

Lugar: Porto Alegre; Año: 2015 vol. 105 p. 316 - 324

0073-4721

Chondrichthyans constitute a successful group with a long and intricate evolutionary history that makes them highly vulnerable. The smallnose fanskate, Sympterygia bonapartii (MÜLLER & HENLE, 1841) is one of the most disembarked items in commercial harbors in Argentina. In this work, the microscopic architecture of mature male gonads and the dynamics of cysts development are analyzed as an interesting tool for understanding the reproductive biology of this specie. Some biological data related to reproduction are given as well. Two seasons were sampled (fall and spring) and length classes? frequency distribution and maturity stages frequency distribution are given. LT50 for males was estimated as 58.01 cm of total length. Testes are symmetric, peer, lobated, with several germinal zones. Inside the gonads, there are many spermatocysts, which contain reproductive cells at the same developmental stage. On the basis of their cytological and microanatomical features, seven maturative degrees of the spermatogenic series were differentiated. Few Leydig cells were recognized at the interstitial tissue between cysts. The microscopic quantitative analysis performed in this work provides a promising tool that may contribute to a better knowledge of the reproductive cycles of this economically and ecologically important species.