Vascularization, morphology and histology of ovary in armadillo Euphractus sexcinctus (Linnaeus, 1758)

Abstract

Euphractus sexcinctus is a species of armadillo from South America and there are not many studies on its reproductive anatomy. Five corpses of adult females were collected according to the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA) guidelines. The ovaries were dissected and processed for histological examination after standard staining with hematoxylin-eosin. The shape of the ovaries was oval, measuring 7,9 mm in length and width 4,4 mm. There was no central concavity in the ovary as opossed to previous reports on armadillos. The ovaries were covered with simple squamous epithelium and connective tissue rich in collagen fibers. The cortical region presented follicles at various stages of development, with primordial follicles being in clusters. The region containing blood vessels and medullary interstitial cells, and sex cord as described in other species of armadillos. The tertiary follicle oocyte measured 183 ± 18 mm diameter, with a spherical nucleus and dispersed chromatin. The zona pellucida was homogeneous and acellular around the oocyte. Follicles with oocyte groups were not identified. This study demonstrated that ovarian morphology of E. sexcinctuswas similar to that of other mammals, but different from other species of armadillos described in other articles.