Figs 13-18 in Ovarian development and spawning of Macrobrachium amazonicum (Crustacea, Decapoda)

Figs 13-18. Ovary sections of Macrobrachium amazonicum (Heller, 1862) at different maturation stages, captured in the Cachoeira II reservoir between November 2014 and August 2017: 13, Immature: oogonia (OO), previtellogenic oocyte (PVO) and follicular cells (between {}); 14, In maturation: previtellogenic oocyte (PVO), initial vitellogenic oocyte (VO I), advanced vitellogenic oocyte (VO II), and cytoplasmic vesicle formation (CV). Clear nucleus and nucleolus (between {}), and spherical follicular cell nodes (star), also around the oocytes; 15, Mature: follicular cells forming a lining around the oocytes, where they are barely perceptible due to their level of proXimity and flattening (FC), and small nucleus (NU). The crystalliZed appearance is due to the accumulation of yolk granules, and the several small uncolored spots characteriZe the cytoplasmic vesicles; 16, Spawned in maturation: oogonia displaying their nuclei and nucleoli (OO), previtellogenic oocyte (PVO), initial vitellogenic oocyte (between []), advanced vitellogenic oocyte (between {}) and postovulatory follicles (POF); 17, Spawned: oogonia (OO), atretic oocyte (AO) and postovulatory follicle (POF); 18, Resting: oogonia (OO) and follicular cell nodes (star). Color: Gomori trichrome (13, 14, 16, 18); HematoXylin-Eosin (15, 17).