Fig. 3 in Gametogenesis and reproductive cycle of Melanorivulus aff. punctatus (Boulenger, 1895) (Cyprinodontiformes, Rivulidae) in Chapada dos Guimarães, Mato Grosso, Brazil

Fig. 3. In the ovaries, stained with toluidine blue-borax, (A) there is the gonoduct, as indicated by the arrow; (B) the germinal epithelium, which presents: somatic cells that stand out of the germinal epithelium and will be the pre-follicular cells (Pf) to accompany the nest of oogonia (circle); (C) some oogonia begin the process of differentiation through meiosis, forming early oocytes (Eo) that stand out from the nest being involved in pre-follicular cells (Pf) characterizing the initial ovarian follicle (black circle), after then other cells come around forming the internal theca (It) and external theca (Et), forming the follicular complex (white circle); (D) the oocyte gives rise to a new stage of growth, the pre-vitellogenic one with the arising of nüages (Ng), multiple nucleoli (No) and the Balbiani corpuscles (Bc); (E) it is possible to observe the anterior structures in greater detail and also the layers of the follicular envelope, which comprises the components of theca (T), a layer of follicular cells (Fc), the basal membrane (Bm) and a pellucid zone (Pz); (F) this zone is composed by small microvilli (Mv) that protrude on the surface of the oocyte and follicular cells.