Acta Parasitologica, Vol. 50, No. 3, 2005, 208-214 Cheikh T. Ba(1)*, Aissatou Ba(1) and Bernard Marchand(2) - Ultrastructure of the spermatozoon of Paroniella reynoldsae (Cyclophyllidea, Davaineidae) an intestinal parasite of Corvus albus (Aves, Corvidae)
(1)Laboratory of Parasitology-Helminthology, Department of Animal Biology, Faculty of Sciences and Techniques, Ch. A. Diop University of Dakar, Dakar, Senegal; (2)Laboratory "Parasites and Mediterranean Ecosystems", Faculty of Sciences and Techniques, University of Corsica Pascal Paoli, B.P. 52, F 20250 Corte, France
*Corresponding author: email@example.com
The mature Paroniella reynoldsae spermatozoon exhibits an apical cone of electron-dense material about 2.2 um long and 0.65 um wide at its base and two helicoidal crest-like bodies roughly 100 to 150 nm thick. The latter are of different lengths, spiralled and make an angle of about 45° with the spermatozoon axis. The axoneme is of the 9 + '1' trepaxonematan pattern and does not reach the posterior extremity of the gamete. The nucleus is an electron-dense cord 0.25 um thick coiled in a spiral around the axoneme. The cytoplasm exhibits a posterior densification and contains few small electron-dense granules in regions I, II and V of the spermatozoon. In regions III and IV, it is divided into irregular compartments by walls of electrondense material. The cortical microtubules are spiralled at an angle of about 45°. The presence of an electron-lucent apical cone
containing numerous small granules of electron-dense material has never, to our knowledge, been reported in a cestode. Likewise, a crest-like body forming a terminal spot of electron-dense material located in the prolongation of the apical cone has never been described before in a cestode. Moreover, in this study, we try to show the existence of tight reciprocal phylogenetic relationships between genera within the Davaineidae and the Anoplocephalidae.
KEY WORDS: Ultrastructure, spermatozoon, Paroniella, Cestoda, Cyclophyllidea, Corvus albus, Aves
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