Ultrastructure of sperm and spermiogenesis of two species of the Tricladida (Platyhelminthes): Romankenkius libidinosus (Paludicola) and an unidentified species of the Maricola

摘要: Summary Sperm of the paludicolan triclad Romankenkius libidinosus consist a distal process and main body, two free flagella arising from zone between both. Flagella are fused for short distance their tips split into long “microvilli” containing microtubules. The single mitochondrion extends to close tip body. nucleus, consisting lucent dense components coiled screw-like around each other, does not extend process. A peripheral row microtubules consists about 37–39 in middle parts sperm, decreasing towards both ends. three inner along most sperm Surface ornamentations present at ends but parts. In early spermatids, joined by cytophores, forms beneath plasma membrane differentiation it an intercentriolar body with several bands connected fila...