Fig. 1

Macroscopic and microcosmic observation of the ovary at different stages of reproductive process. a Ovary at the stage of post-mating. Its overall color is yellow, because of fewer blood vessels in the ovary. b Ovary after fertilization, at the early stage of gestation. Its overall color is pink or red, because the well-developed blood vessels spread over the surface of egg membrane. c Ovary at the final stage of gestation. Its overall color is dark, because of developed pigment. The silvery reflections are the individual eyes of the larvae within the ovary. As time goes by, the ovary will enlarge the volume and the ovarian wall will become very thin until the finish of parturition. d Ovary post parturition. Most embryos came out from cloacal orifice via abdomen extrusion. e Ovary before mating. Oocytes are opaque. Only a few of blood vessels were observed. f Ovary after mating. Oocytes develop further, becoming transparent. g Ovary before fertilization. Oocytes are fully developed and ready for fertilization. The highly vascular membranous tissue adjacent to the egg membrane. h Ovary during gestation. The eyes of embryo formed