Histological characteristics of the ovary of Jenynsia lineata, a viviparous fish

DI CESARE LUCA; MONTES M.M.; PLAUL S.E.; BARBEITO C.G

Simposio; XXXIIIrd Congress of the European Association of Veterinary Anatomists; 2021

Introduction: Jenynsia lineata (Cyprinodontiformes, Anablepidae) is a native viviparous freshwater fishcurrently used as an experimental model for toxicological and environmental impact studies. Previousstudies of this viviparous fish have not focused on the histological structure of the ovary. The objectiveof this study was to analyze and describe the histological structure of the ovary both in its gestationaland non-gestational phases by means of different histological stainsMaterials and Methods: Fourteen females of J. lineata (7 in each phase) were sacrificed by anestheticoverdose according to the Ethics Committee for the Use of Laboratory Animals (CICUAL) of FCV, UNLP.The ovaries were rapidly excised and fixed by immersion in 10% buffered formalin. Samples wereroutinely processed and embedded in paraffin wax. The ovaries were serially sectioned at 5-6 μmthickness and then were stained with Hematoxylin & Eosin, Masson´s trichrome and Periodic AcidSchiff. Histological sections were observed under a light microscope with an image capture system(Leica DFC 280).Results: The ovary of J. lineata was characterized as an unpaired hollow organ, histologically formedby a tunica mucosa-submucosa, a thin tunica muscularis and a tunica serosa, with a central lumenthat decreased when the females were in the gestation period. In the advanced stages of gestation, itwas observed that the richly vascularized ovarian lamellae entered through the opercular clefts ofthe embryos and entered in close contact with the embryonic capillaries of the gill processes.Conclusion: The results presented here show novel histological changes in the ovary of J lineata bothin its gestational and non-gestational periods.