ULTRASTRUCTURAL SIMILARITY OF THE SPERMAT OZOA OF SOME CYCLOPHYLLIDEA

The mature spermatozoa of Cotugnia polyacantha, Raillietina (R) tunete nsis, Inermicapsifer madagascariensis and Avitellina centripunctata ha ve an almost identical ultrastructural organization. They are tapered at both extremities. Their anterior extremity exhibits an apical cone of electron dense material and one or two helicoidal crested-like bodi es. Their cortical microtubules are spiralized and are seen, in longit udinal and cross sections, as continuous, dense, submembranous materia l. Their nucleus is a cord of dense chromatin, coiled in a spiral arou nd the 9 + ''1'' pattern axoneme. The cytoplasm is moderately dense to electron lucent and exhibits irregularly spaced walls of proteinaceou s material and a fine periaxonemal sheath of dense material. In this w ork we show that the Anoplocephalidae are close to the Davaineidae by the characters of the spermatozoon and that lnermicapsifer should be p ut back among the Davaineidae, according to the opinion of Joyeux & Ba er (1961) and come into conflict with other works, more particularly S chmidt (1986).