Ultrastructure of the spermatozoon of Raillietina (Raillietina) baeri (Cyclophyllidea, Davaineidae) an intestinal parasite of the multimammate rat, Mastomys huberti (Rodentia, Muridae)

Abstract

The mature Raillietina (Raillietina) baeri spermatozoon exhibits an apical cone of electron-dense material about 2.5 microm long and 0.5 microm wide and two helicoidal crest-like bodies roughly 100-125 nm thick. The latter are of different lengths, spiralized and stand in an angle of about 50 degrees with the spermatozoon axis. The axoneme is of the 9 + "1" pattern and does not reach the posterior extremity of the gamete. The nucleus is an electron-dense cord 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 electron-dense material. The cortical microtubules are spiralized and make an angle of 40-50 degrees to the spermatozoon axis. In this work, we describe, for the first time, a spermatozoon of a davaineidaean cestode parasitic of mammals. This has enabled us to show a wide apical cone, which has never been described before in a cyclophyllidean species the spermatozoon of which has two crest-like bodies.

Ultrastructure of spermiogenesis and mature spermatozoon of Angularella beema (Clerc, 1906) (Cestoda, Cyclophyllidea, Dilepididae)

“…Two families, Catenotaeniidae and Davaineidae, are characterised by the presence of two crested bodies on the mature spermatozoon Hidalgo et al 2000;Bâ and Marchand 1994c;Bâ et al 2005a, b). The spermatozoa of the Hymenolepididae possess multiple (6-12) crested bodies, while the species of the Anoplocephalidae are characterised by 1 or 2 crested bodies (in two species only, K. delafondi and S. taterae, 5 and 7 crested bodies, respectively, were described, see Marchand 1994a, Bâ et al 2000).…”

“…Granular inclusions found in the spermatozoon of A. beema, which probably are of glycogenic nature, were similar to those present in the dipylidiids, nematotaeniids, mesocestoidids and hymenolepidids. Inclusions are lacking in the spermatozoa of the Metadilepididae (see Yoneva et al 2006), Davaineidae (see Bâ and Marchand 1994c;Bâ et al 2005a, b), Catenotaeniidae (see and Taeniidae (see Miquel et al 2000, Ndiaye et al 2003a. For the moment, the presence and the character of the inclusions seem to be of limited value for the purposes of phylogenetic studies but their possible implication should be revisited when more data are accumulated.…”

Ultrastructure of spermiogenesis and mature spermatozoon of Skrjabinoporus merops (Cyclophyllidea, Metadilepididae)

“…Within this family, a distinction using spermiological data can be made between subfamilies (Justine 1998). The other data from cyclophyllideans include: Catenotaeniidae -Catenotaenia pusilla and Skrjabinotaenia lobata (see OEwiderski 1970; Taeniidae -Echinococcus granulosus, E. multilocularis, Taenia hydatigena, T. mustelae, T. parva, T. solium and T. crassiceps (see Morseth 1969;Featherston 1971;Shi et al 1994;Miquel et al 2000;Ndiaye et al 2003a;Willms et al 2003Willms et al , 2004; Mesocestoididae -Mesocestoides litteratus (see Miquel et al 1999); Nematotaeniidae -Nematotaenia chantalae (see Mokhtar-Maamouri and Azzouz-Draoui 1990); Hymenolepididae -Retinometra serrata, Hymenolepis nana, H. straminea, Vampirolepis microstoma and Echinocotyle dolosa (see Bâ and Marchand 1992a, 1993, 1998Bâ et al 2002); Davaineidae -Raillietina tunetensis, R. baeri and Paroniella reynoldsae (see Bâ and Marchand 1994c;Bâ et al 2005a, b); Dipylidiidae -Dipylidium caninum, Joyeuxiella echinorhynchoides and J. pasqualei (see Miquel and March-Spermiogenesis and spermatozoon ultrastructure of S. merops 201…”

Ultrastructure of the spermatozoon of Calliobothrium verticillatum (Cestoda, Tetraphyllidea, Oncobothriidae)

“…For these groups, this number is about 40 longitudinal microtubules spaced regularly at the periphery (Justine 1991). Moreover, these microtubules are not spiralled as in Cyclophyllidea (Justine 1991;Bâ and Marchand 1992a, b;Miquel et al 1999;Bâ et al 2000Bâ et al , 2002Bâ et al , 2005). An other ultrastructural particularity is the presence of 10 cortical microtubules disposed in semi-circle around the axoneme in the region V. This observation was made in all the Tetraphyllidea (Table I).…”

“…Euzet et al (1981) and Bâ and Marchand (1995) wrote on this complex subject. Among the fifteen orders comporting the Cestoda (Schmidt 1986), differences have been remarked in the spermatozoon like the number of crested bodies (Bâ and Marchand 1994a), the disposition of cortical microtubules (Bâ and Marchand 1992a, b;Eira et al 2006) or the presence of an apical cone (Bâ et al 1991, Bâ and Marchand 1994b, Bâ, et al 2005. Moreover, if the axonemes are 9 + "1" pattern of Trepaxonemata like in most other parasitic Platyhelminthes, the number of axonemes changes according to the order or the family.…”