Spermatogenesis and spermatozoon ultrastructure in Dugesia sicula Lepori, 1948 (Platyhelminthes, Tricladida, Paludicola)

摘要: We examine for the first time spermatogenesis, spermiogenesis and spermatozoon ultrastructure in Dugesia sicula Lepori, 1948 a sexual diploid planarian living Tunisian springs. This TEM-study shows that early spermatids joined by cytophores have rounded nuclei. During spermiogenesis, row of microtubules appears differentiation zone beneath plasma membrane close to intercentriolar body, which consists several dense bands connected filaments. Two free flagella (9+1 configuration) grow out - side spermatid. An apical layer nucleoplasm develops flagellum appear, facing opposite directions before rotating lie parallel each other after body splits into two halves. Mitochondria are closely packed around spermatocyte nucleus fusing during form long mitochondrion, lies elongated along ripe spermatozoon. The latter is thread-shaped regions: proximal process distal part. former contains part mitochondrion. rest mitochondrion tapering tail nucleus. Separation between these regions marked externally insertion flagella. extend posteriorly dis tal lucent component coiled screw-like pattern other. single peripheral maximum 40 middle with an internal three supplementary microtubules.