COMPARATIVE ULTRASTRUCTURE OF THE SPERMATOZOA OF INERMICAPSIFER GUINEENSIS AND INERMICAPSIFER MADAGASCARIENSIS (CESTODA, ANOPLOCEPHALIDAE, INERMICAPSIFERINAE), INTESTINAL PARASITES OF RODENTS IN SENEGAL

Spermatozoa of Inermicapsifer guineensis and Inermicapsifer madagascar iensis are filiform and tapered at both extremities. The anterior extr emity exhibits an apical cone of electron-dense material and two helic al ridges. The axoneme, of the 9 + ''1'' pattern, is surrounded over p art of its length by a sheath of electron-dense material. At the poste rior extremity the cytoplasm contains electron-dense material. In regi ons III and IV of the spermatozoa the cytoplasm is subdivided into com partments of electron-lucent material limited by irregularly spaced wa lls of electron-dense material. The sperm nucleus is a compact cord wo und in a spiral around the axoneme. Cortical microtubules are helicall y arranged down the length of the spermatozoa except at the posterior extremity where they run parallel to the spermatozoon axis. In I. mada gascariensis, cortical microtubules may not extend as far as the poste rior extremity of the spermatozoa; the dense periaxonemal material exi sts in regions I to TV of the spermatozoon and the nucleus never coils more than once around the axoneme.