title: Ultrastructural study of the spermatozoon of Pronoprymna ventricosa (Digenea, Baccigerinae), parasite of the twaite shad Alosa fallax Lacepede (Pisces, Teleostei).
abstract: In this paper, we describe the ultrastructural organisation of the spermatozoon of a Digenea Baccigerinae Pronoprymna ventricosa. This spermatozoon possesses the elements found in the others digeneans: two axonemes with 9 + "1" pattern, a mitochondrion, a nucleus, cortical microtubules and external ornamentations. However, this spermatozoon presents two particularities. The first is the presence of a single field of cortical microtubules disposed in the ventral side (mitochondrion side) of the spermatozoon. In the other digeneans, two fields of cortical microtubules are observed between the two axonemes. The second is the presence of external ornamentations not associated with cortical microtubules. These two points have, to our knowledge, never been described in another digenean. Moreover, a separation in two groups of the digenean spermatozoa is proposed in relation to the localisation of the external ornamentations. We propose to distinguish a first group exhibiting these elements in the proximal part of the spermatozoon and a second one with external ornamentations in a second part of the gamete.
authors.affiliation: Laboratoire Parasites et Ecosystèmes méditerranéens, Faculté des Sciences et Techniques, Université de Corse, Campus Grossetti, 20250 Corte, France. quilichini@univ-corse.fr
authors.forename: Yann
authors.initials: Y
authors.lastname: Quilichini
authors.forename: Josephine
authors.initials: J
authors.lastname: Foata
authors.forename: Bernard
authors.initials: B
authors.lastname: Marchand
mesh_terms: D000818:Animals; D005393:Fish Diseases / Q000469:parasitology*; D005399:Fishes / Q000469:parasitology*; D008297:Male; D013094:Spermatozoa / Q000648:ultrastructure*; D014200:Trematoda / Q000648:ultrastructure*; D014201:Trematode Infections / Q000469:parasitology / Q000662:veterinary*