Figure 7

Late sporogonial stages of Dictyocoela berillonum from Pontogammarus robustiodes. (A,B) Section of the sporophorous vesicles (sv) containing sporoblasts (A) and spores (B). The sv space is filled with thin granular material and not numerous septate tubules (arrow). (C) Part of immature spore with polyribosomes (arrow). (D) Anterior part of immature spore with anchoring apparatus, polar sac (ps), manubrial part of polar filament (pf), thin lamellar anterior polaroplast (ap), and cysterns of posterior polaroplast (pp). The spore wall is narrowed at the apical pole. (E) Anterior part of mature spore with lamellar posterior polaroplast (pp) and posterior vacuole (pv). Tubular inclusions, structure of the spore wall and coiled part of polar filament (pf) are visible. (F) Ultrastructure of the spore wall. The plasmalemma, endospore (en) and two layers of exospore (ex) are presented. (H) Oblique section of mature spore. Anterior polaroplast (ap), single nucleus (nu), 5–6 coils of the polar filament (pf), posterior vacuole (pv), and inclusions (arrow) inside sporophorous vacuole (sv) are displayed. Scale bars: 40 nm (F); 300 nm (D); 400 nm (H); 500 nm (C,E); 1.5 µm (A,B).