Fig. 3. TEM of sporogonial stages of E. hepatopenaei development in hepatopancreatic tubule epithelial cells of P. monodon. (A) Early sporogonial plasmodium containing
nuclei (asterisks), clear vesicles (inset a, arrowhead), and precursors of polar filaments (inset a, arrows; and inset b). (B) Sporogonial plasmodium with peripherally located
sporoplasm (asterisk). (C) Sporogonial plasmodium with several peripherally located pre-sporoblasts (asterisks). (D) Plasmodial membrane showing a microvillus-like
structure surrounded by host-cell cytoplasm (arrow) containing extensive RER (arrowhead). (E) Thickened plasmodial plasmalemma showing vesicular structures at the
interface with host cytoplasm (arrowhead). (F) Late sporogonial plasmodium showing assembled pre-sporoblasts, polar filaments and a dense cap (arrowhead).