Fine structure and function of the genital pore of the female of Intoshia variabili (Orthonectida).

The genital pore of the female of Intoshia variabili Aleksandrov et Sljusarev, 1992 is located on a transverse ring of non-ciliated cells. Before copulation it is occupied by 6-7 cells that develop in the epithelium and that for a time are beneath the surface. When fully developed, these cells contain many electron-dense granules and their apical surface is covered with numerous microvilli. After copulation the granules disappear and the apical surface becomes smooth. The cells still form a plug closing the opening. After one larva pushes the pore cells out and escapes, others follow.