Ultrastructural Study of Spermiogenesis and Spermatozoon of Porrorchis Indicus (Das, 1957) Schmidt and Kuntz, 1967 (Acanthocephala, Palaeacanthocephala, Plagiorhynchidae) From the Egyptian Centropus Senegalensis Aegyptius (Aves: Cuculidae)

Abstract

Porrorchis indicus is an endoparasite of the Egyptian birds, Centropus Senegalensis aegyptius. This parasite causes damage to the gut wall of the infected birds. Spermiogenesis and sperm ultrastructure have been widely used in the phylogeny of parasitic platyhelminthic and acanthocephalan worms. However, there are limited ultrastructural data available on spermiogenesis and the spermatozoon on the acanthocephalan family, plagiorhynchidae to which P. indicus belongs. The present study investigated the ultrastructure features of the different stages of P. indicus spermiogenesis. The morphology and anatomy of the spermatozoa was described in comparison with the previous reports. Different ultrathin sections of the body of P. indicus (testes and vas deferens) were cut using transmission electron microscopy (TEM) to describe the different stages of the spermiogenesis as well as both morphology and anatomy of spermatozoa.The results showed that the primary spermatocystes of P. indicus was rounded shape with large rounded nuclei and high nucleocytoplasmic ratio. The secondary spermatocystes showed nearly ovoid shape; each possessed a small nucleus and numerous mitochondria. The early spermatid possessed a large nucleus and contained a single centriole. The early spermatid showed a posterior bulb in which the centriole had a flagellum with 9+0 pattern surrounded by a plasma membrane it changed into 9+2 pattern. The cytoplasmic canal is characterized by a ring form which appeared around the axoneme. The anterior extremity of the spermatozoa showed the presence of the centriolar derivative that had three different stages. The first is made of nine peripheral elements. The second is of nine peripheral and one central element. The third showed nine peripheral and two central elements. The centriolar derivative is followed by a flagellum with a 9+2 pattern. In mature spermatozoa, protein granules different sizes, numbers and shapes were recognized.