Ultrastructural spermatid and sperm morphology in Poecilocerus pictus (Fab.) with a reference to spermeiophagic cells in the testis and sperm duct

Electron microscopical studies were carried out on spermatid and sperm structure in P. pictus. The spermatid nuclear envelope possesses pores and is surrounded by microtubules which disappear on metamorphosis to sperm though centriolar adjunct, and its corresponding centriole comprising the basal body for flagellum. remains persistent in both. The mitochondria are arranged as two fused bodies with prominent cristae flanking the central axoneme and also contain curved end feet. In axoneme the microtubular complex is comprised of 9 + 9 (doublet) + 2 tubules + nine coarse fibres and also reveals nine radial links with electron-dense link heads. In P. pictus an alteration in temperature range, ambient for its rearing and generation of fertile spermatozoa, induces the production of sterile sperms which are characterized by multiple axonemes and mitochondrial bodies engirdled by a common plasma membrane. Presence of phagocytic cells is also an essential feature of its testis and vas deferens. These spermeiophagic cells engulf the neighbouring spermatozoa as evidenced by the fragments of axoneme, nuclei, and acrosomes in their cytoplasm.