Ultrastructure of Nosema stenocypris Diarra & Toguebaye, 1994, a Microsporidian Parasite of Stenocypris major (Crustacea, Ostracoda, Cyprididae)

Nosema stenocypris Diarra & Toguebaye, 1994 (Microsporida, Nosematidae) has been described from Stenocypris major (Crustacea, Ostracoda, Cyprididae). It develops in the muscles. Merogonial stages were not observed. The cellular envelope of young sporonts grows in thickness by addition of electron-dense material external to the plasma membrane. The sporoblasts are bounded by a thick electron-dense wall and transform directly into spores. Live mature spores are ovoid and measure 4.28 ± 0.19×2.61 ± 0.10 µm. Their wall can reach a thickness of 190 nm. The polar filament is isofilar with 14 coils and the polaroplast has an anterior lamellar part and a posterior vesicular part.