title: Spermatogenesis in free living mite, Pergamasus viator Halaŝ. (Parasitidae, Mesostigmata). II. Spermiogenesis.
abstract: The paper presents the results of ultrastructural studies on the spermiogenesis in the mite, Pergamasus viator Halaŝkova. The cysts containing 16 spermatids per cyst, are localized in the anterior part of the saccular gonad. The process of spermatid maturation has been divided into three stages: of the early spermatid, middle spermatid and late spermatid. The modifications of spermatid occuring during the spermiogenesis include: a change of cell shape, modifications of its organelles and formation of new structures like the superficial layer of cellular processes, striated bodies, granular bodies, flattened cisternae and canaliculi, central canaliculi, and stiff bands. Within the nucleus the chromatin condenses to threads or lamellae, to form subsequently several electron-dense granules. The remaining nucleoplasm is filled with an electron-dense material, which appears in the middle spermatid and gradually accumulates. The above modifications occuring in the course of spermiogenesis and their relation to the data available from the literature concerning the spermatogenesis of allied groups of animals are discussed in length.
mesh_terms: D000818:Animals; D002843:Chromatin / Q000502:physiology; D008297:Male; D008854:Microscopy, Electron; D008925:Mites / Q000502:physiology*; D011044:Poland; D013045:Species Specificity; D013091:Spermatogenesis; D013094:Spermatozoa / Q000502:physiology
chemical_list: D002843:Chromatin