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Philotolepis raymondi [Gigon et Beuret, 1991] comb.n. [Cyclophyllidea, Dilepididae]: new geographical record and synonymy

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Georgiev B. B. , Genov T.

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nr 3

EN

Ptilotolepis raymondi (Gigon et Beuret, 1991) comb. n. (Syns. Unciunia raymondi Gigon et Beuret, 1991; Ptilotolepis philomelae Okulewicz, 1991, new synonymy) is recorded and redescribed from Turdus philomelos (Passeriformes, Muscicapidae, Turdinae) in Bulgaria. The same specimens were mentioned as Anomotaenia constricta by Paspalev and Paspaleva 1972 and as Ptilotolepis sp. by Georgiev 1990. P. raymondi is regarded as a species specific parasite of T. philomelos.

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Oncospheral hook morphogenesis in the cestode Dilepis undula [Schrank, 1788] [Cyclophyllidea, Dilepididae]

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Swiderski Z. , Tkach V. V. , Salamatin R. V.

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nr 4

EN

Ultrastructural aspects of the oncospheral hook morphogenesis in the dilepidid cestode, Dilepis undula (Schrank, 1788), are described. Oncospheral hook primordia appear within specialised cells, so-called oncoblasts, at the preoncospheral stage of the embryogenesis. Extended Golgi regions, numerous free ribosomes and mitochondria are involved in the hook development. During the hook growth, the blade and base gradually protrude outside the oncoblast plasma membrane. The nucleated oncoblasts persist around the handles of the fully formed hooks even in the mature oncospheres. The mature hooks in the cross-section consist of two to four layers of different electron density, depending on the level of the section; two of them, namely the highly electron-dense cortex and a moderately electron-dense core, are observed in all parts of the hook. A circular, septate desmosome and two electron-dense rings on its both sides are formed around the exits of the hook blades from the oncospheral tegument. Each hook blade has a protective moderately electron-dense “cap” on its tip. A hook region membrane, similar to that described in other cyclophyllideans, forms on the surface of the oncosphere a cavity covering the hook blades. The hook muscle attachment zones at the hook guard and base are represented by a relatively thick layer of fibrous material. The peculiarities of the oncospheral hook formation in Dilepis undula are compared with the results of our previous studies and literature data on other cestodes so far studied in this respect.

3

Fine structure of the infective eggs of the dilepidid cestode Hepatocestus hepaticus [Baer, 1932], a parasite of shrews

63%

Swiderski Z. , Tkach V. V. , Vaucher C.

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nr 2

EN

Ultrastructural characteristics of the eggs of the dilepidid cestode, Hepatocestus hepaticus, is described. The mature oncosphere is surrounded by three envelopes: (1) an outer envelope; (2) an inner envelope consisting of three layers - an extraembryophoral cytoplasmic layer, a thick, fibrillar, low electron-dense embryophore, and intraembryophoral cytoplasmic layer, (3) a thin oncospheral membrane, surrounding the oncosphere. The whole surface of the oncosphere is covered by the cytoplasmic oncospheral tegument with numerous short microvilli and a layer of subtegumental somatic muscles. The following cell types were distinguished in the mature oncospheres: the U-shaped penetration gland a containing a large amount of tightly packed secretory granules; bi-nucleate perikaryon of the oncospheral tegument; somatic cells (= myocytons of somatic and hook muscles); and the germinative cells. The hook-muscle system consists of three pairs of embryonic hooks and a complex system of specialised muscle fibers responsible for the coordinated hook movements. The ultrastructural characteristics of H. hepaticus oncosphere are discussed in comparison with those of previously studied dilepidids and other cyclophyllideans.

4

Ultrastructure of spermiogenesis and mature spermatozoon of Angularella beema [Clerc, 1906] [Cestoda, Cyclophyllidea, Delepididae]

63%

Yoneva A. , Miquel J. , Swiderski Z. , Georgieva K. , Mizinska Y. , Georgiev B. B.

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nr 4

EN

The ultrastructure of the spermiogenesis of a dilepidid cestode species is described for the first time. The spermiogenesis of Angularella beema is characterised by absence of both flagellar rotation and proximodistal fusion. The differentiation zone is surrounded by cortical microtubules and is delimited by a ring of arching membranes. It contains two centrioles, one of which develops the axoneme that grows directly into the elongating cytoplasmic protrusion. This pattern of spermiogenesis was described as the Type IV spermiogenesis of cestodes. Among cestodes, similar pattern of spermiogenesis is known in the family Hymenolepididae and in some representatives of the family Anoplocephalidae. The mature spermatozoon of A. beema consists of five regions differing in their ultrastructural characteristics. It is characterised by the presence of cortical microtubules (spirally arranged at angle of 30–40° to the spermatozoon axis) and a single crested body. There is a periaxonemal sheath in certain parts of the spermatozoon as well as glycogen-like granules between the periaxonemal sheath and the cortical microtubules. The comparisons of the mature spermatozoon of A. beema with those of other two dilepidid species (Dilepis undula and Molluscotaenia crassiscolex) demonstrate some variation within the family: presence of periaxonemal sheath in A. beema and D. undula and its absence in M. crassiscolex; presence of electron-dense rods in D. undula and their absence in A. beema.

5

Some further propositions of new generic combinations or emendations for tapeworms recorded in Poland

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Pojmanska T. , Czaplinski B.

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nr 1

EN

As the continuation of review of the generic names used for the tapeworms recorded in Poland (Pojmańska 1996), the changes in generic combinations for 9 cestode species are proposed.