title: Reproductive system of females of the Magdalena river endemic stingray Potamotrygon magdalenae: Anatomical and functional aspects.
abstract: We studied anatomical and functional aspects of the reproductive system of females of the Magdalena river stingray Potamotrygon magdalenae using microscopic and macroscopic analysis of each organ. Although the reproductive tract was fully functional on both side, the left organs possibly have a greater contribution to reproductive success, because left ovary and uterus were more developed and had higher number of oocytes and embryos, respectively, than the right ones. This species has histotrophic viviparity given by the presence of uterine trophonemata and by glandular character in pregnant and postpartum females. We suggest that the epigonal organ is involved in the degradation of components of atretic follicles and the embryos begin to develop surrounded by a gelatinous tertiary envelope produced by the oviducal gland. This latter organ is composed by three zones in mature females, club, papillary, and baffle zone, as described for other elasmobranchs. From the anatomical observations, a maturity scale comprising six sexual maturity stages (Immature I, Immature II, early mature, pregnant, post-partum, and regenerating) was established for female P. magdalenae, and it can be useful as basis for reproductive studies of other potamotrygonid species. Finally, we propose a continuous reproductive cycle for P. magdalenae.
authors.affiliation: Facultad de Ciencias, Fundación colombiana para la investigación y conservación de tiburones y rayas, SQUALUS, 60A No 11-39, Carrera, Cali, Colombia.
authors.forename: Tania
authors.initials: T
authors.lastname: del Mar Pedreros-Sierra
authors.affiliation: Facultad de Ciencias, Fundación colombiana para la investigación y conservación de tiburones y rayas, SQUALUS, 60A No 11-39, Carrera, Cali, Colombia.|Facultad de Ciencias, Escuela de Biología, Universidad Industrial de Santander, Carrera 27 Calle 9, Bucaramanga, Colombia.
authors.forename: Dagoberto M
authors.initials: DM
authors.lastname: Arrieta-Prieto
authors.affiliation: Facultad de Ciencias, Fundación colombiana para la investigación y conservación de tiburones y rayas, SQUALUS, 60A No 11-39, Carrera, Cali, Colombia.
authors.forename: Paola A
authors.initials: PA
authors.lastname: Mejía-Falla
mesh_terms: D000818:Animals; D005260:Female; D005836:Genitalia, Female / Q000033:anatomy & histology*; D045483:Rivers; D012860:Skates, Fish / Q000033:anatomy & histology*
keywords: freshwater stingray; histochemistry; histology; maturity stages; ornamental