Pergamon Internorional Journalfor Parasitology. Vol. 24, No. 2, pp. 225-235, 1994 Copyright 0 1994 Australian Society for Parasitology Elsetier Science Ltd Printed in Great Britain. All rights resewed 002&7519/94 S7.00+ 0.00 ULTRASTRUCTURE OF SPERMIOGENESIS AND THE SPERMATOZOON OF APORINA DELAFONDI (CYCLOPHYLLIDEA, ANOPLOCEPHALIDAE), INTESTINAL PARASITE OF TURTLE DOVES IN SENEGAL CHEIKH TIDIANE BA* and BERNARD MARCHAND Laboratory of Parasitology, Department of Animal Biology, Faculty of Sciences, Cheikh Anta Diop University of Dakar, Dakar, Senegal (Received 6 April 1993; accepted 26 August 1993) Abstract-B.4 C. T. and MARCHAND B. 1994. Ultrastructure of spermiogenesis and the spermatozoon of Aporina delafondi (Cyclophyllidea, Anoplocephalidae), intestinal parasite of turtle doves in Senegal. International Journal for Parasitology 24: 22>235. Spermiogenesis in Aporina delafondi begins with the formation of a differentiation zone bordered by cortical microtubules and containing from the beginning a portion of nucleus and two parallel centrioles. One of the centrioles aborts, the other gives rise to a flagellum. The cortical microtubules elongate and spiralize while the nucleus migrates along the axoneme and crest-like bodies form at the level of the differentiation zone. The old spermatid separates from the residual cytoplasm by strangulation of the ring of arched membranes. The mature spermatozoon lacks mitochondria, is tiliform and tapered at both its extremities. Its anterior extremity is capped by an apical cone of electron-dense material and exhibits five crest-like bodies of unequal lengths on its periphery. Its cortical microtubules are regularly spiralized except at their posterior extremity where they become parallel to the spermatozoon axis. The cytoplasm is slightly dense in the anterior regions (I and II) and exhibits many protein granules and patches of electron-lucent material in the middle (III) and posterior zones (IV and V). The nucleus is an electron-dense cord coiled in a spiral around the middle region (III) of the axoneme. This is of the 9 + “1” pattern and ends before the posterior extremity of the gamete. Spermiogenesis in Aporina delafondi differs from that of the other Cyclophyllidea by the very early movement of the nucleus into the differentiation zone, the formation of a ring of arched membranes in the distal part of the differentiation zone, the appearance of crest-like bodies during migration of the nucleus and the formation of a cytoplasmic bud which contains the abortive centriole and develops to temporarily form a large lateral extension. The mature spermatozoon differs from that of the other Cyclophyllidea in the presence of lucent patches in its cytoplasm and of five helicoidal crest-like bodies. The systematic position of the genus Aporina is also debated. INDEX KEY WORDS: Aporina aklafondi; spermatozoon; spermiogenesis; ultrastructure; turtle doves; Cyclophyllidea; Anoplocephalidae; Senegal INTRODUCTION ONLY a few authors to date have taken an interest in spermiogenesis of the Cyclophyllidea (Rosario, 1964; Featherston, 1971; Kelsoe, Ubelakker & Allison, 1977; Robinson & Bogitsh, 1978; Mokhtar-Maamouri & Azzouz-Draoui, 1990; BB, Marchand & Mattei, 1991; BP & Marchand, 1992b, in press b). In Thysaniezia ovilla it was demonstrated by BB et al. (1991) that the crest-like body or bodies always mark the anterior extremity of the cestode spermatozoon. A *To whom all correspondence should be addressed at: Laboratoire de Parasitologie, Departement de Biologie animale, Facultt des Sciences, Universite Ch. A. Diop de Dakar, Senegal. study of spermiogenesis and the spermatozoon of another Anoplocephalidae, Mathevotaenia herpestis by Bb & Marchand (in press b) revealed for the first time the existence of centrioles flanked by ciliary roots in a Platyhelminth and a nucleus with an annular cross section in a Cestode. In the present work we describe the ultrastructure of spermiogenesis and the spermato- zoon of A. delafondi. MATERIALS AND METHODS The specimens of A. delafondi were gathered from the small intestine of Streptopelia senegalensis (Laughing Dove) and kept alive for several hours in a 9%oNaCl solution. Seminal vesicles and testes were removed under a binocular microscope, then fixed for 24 h at 4°C with 2.5% glutaraldehyde in a 0.1 M-sodium cacodylate buffer at pH 7.2, 225