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Vitellogenesis in Mosgovoyia ctenoides was examined by means of transmission electron microscopy. Mature vitelline follicles consist of cells in various stages of development, progressing from immature cells of gonial type near the periphery to mature vitellocytes towards the centre. Maturation is characterized by: (1) increase in cell volume; (2) extensive development of large parallel cisternae of granular endoplasmic reticulum (GER), the vitelline material producing units; (3) development of Golgi complexes engaged in vitelline material package; (4) continuous fusion of small vesicles into larger vitelline vesicles and fusion of these into a single very large vesicle, which is characteristic for mature vitellocytes of this tapeworm. Vitellogenesis in M ctenoides is compared with that in other cestodes. Some conclusions concerning the interrelationship between the vitellogenesis pattern and the type of embryogenesis are drawn and discussed.
This study includes a redescription of Anoplocephaloides iudicata (Sawada et Papasarathorn, 1966) comb. nov. (Cestoda, Anoplocephalidae) based on museum material from the South-East Asian Tapirus indicus, comparison with Flabelloskrjabinia tapirus (Chin, 1938) from the South American Tapirus terrestris, as well as comments on the genus Flabelloskrjabinia Spasskii, 1951. The present analysis suggests that A. iudicata and F. tapirus are independent species parasitizing T. indicus and T. terrestris, respectively, distinguished primarily by the size and morphology of the scolex and distribution of testes. However, new material from T. terrestris is needed for the evaluation of the generic status of anoplocephalid cestodes from tapirs.
Spermatogenesis in Gallegoides arfaai is similar to that described for other cestode species. Six incomplete synchronic cytokineses occur: four mitotic and two meiotic cell divisions. The primary spermatogonium divides forming two secondary spermatogonia. All further divisions occur simultaneously, resulting in a rosette of four tertiary, then eight quaternary spermatogonia and sixteen primary spermatocytes. The first meiotic division forms thirty-two secondary spermatocytes and after the second meiotic division sixty-four spermatids are formed. Spermiogenesis begins with the formation of a differentiation zone in the form of a conical projection of cytoplasm delimited by a ring of arching membranes. Within this area there are two centrioles, a centriolar adjunct and vestigial striated rootlets. During spermiogenesis, only one of the centrioles develops an axoneme that grows directly into the cytoplasmic extension. The other centriole remains oriented in a cytoplasmic bud and posteriorly aborts. The nucleus elongates and moves into the cytoplasmic extension. Granular material present in each sperm originates from electron-dense material present in the periphery of the spermatid. In the final stage of spermiogenesis two crest-like bodies appear at the Bâse of the spermatid. Finally, the ring of arching membranes constricts and the young spermatozoon detaches from the residual cytoplasm. In order to increase homogeneity in the designation of the non-typical striated rootlets previously described, in this study we propose to group them under the common designation of "vestigial striated rootlets" and its importance is discussed according to previous findings of related structures in other cyclophyllideans.
The research into the Oribatid mites was conducted in the Bielańsko-Tyniecki Landscape Park in Cracow in locations where horses and sheep periodically grazed. The research material comprised soil samples collected from three sites. Site I - a fenced area, which was exposed to the sun, overgrown with grass, and located on an elevation where sheep were pastured. Site 2 was located in the vicinity of a horse paddock. The soil in Site 2 was compacted and had sparse vegetation. Site 3, located in lower areas, was a meadow adjacent to the Vistula river bank, which was used as a horse pasture by a riding school. Soil samples of 10 × 10 cm in size and 5-10 cm in depth sometimes contained the remains of animal feces and a mite microenvironment (grass tussocks). The mites were obtained from the soil in Tullgren funnels; subsequently they were sorted out and the content of their bodies marked and analysed in preparations made by using Grandjean’s method (14). In the collected research material species participating in the life cycle of tapeworms constituted 85% in Site 1, 82% in Site 2 and 92% in Site 3. There were the following species: Scheloribates laevigatus (C. L. Koch, 1836), Liebstadia similis (Michael, 1886), Galumna elimata (C. L. Koch, 1841), Galumna obvia (Berlese, 1914), Ceratozetes gracilis (Michael, 1884), Ceratozetes peritus (Grandjean, 1951), Achipteria coleoptrata (Linne, 1758) as well as Trichoribates novus (Sellenick, 1928). In 2 out of 880 examined specimens the presence of tapeworms at two developmental stages was confirmed. They were: an egg in the species Liebstadia similis and a cysticercoid in Achipteria coleoptrata. The results show that it is useful to study Oribatida on small pastures because in such places there are favorable conditions for the mite and animal feces to meet in a confined area.
Fertilization in the anoplocephalid cestode Gallegoides arfaai with uniflagellate spermatozoa was examined by means of light and transmission electron microscopy. Fertilization in this species occurs in the oviduct lumen or in the fertilization canal proximal to the ootype, where the formation of the embryonic capsule precludes sperm contact with the oocyte. Cortical granules are not present in the cytoplasm of oocytes of this species. However, two other types of large bodies containing granular material, one of homogeneous moderate electron density and one of heterogeneous moderate electron density, are present in the perinuclear cytoplasm of the oocytes. Spermatozoa coil spirally around the oocytes and syngamy occurs by lateral fusion of oocyte and sperm plasma membranes. In the ootype, one vitellocyte associates with the fertilized oocyte, forming a membranous capsule which encloses both cell types. In this stage, spirally coiled sperm flagella adhere partly to the external oocyte surfaces, and partially enter into the perinuclear cytoplasm. Usually, several loops of the spermatozoon occur within the oocyte cytoplasm. The electron-dense sperm nucleus becomes progressively electron-lucent within the oocyte cytoplasm after entry. Simultaneously with chromatin decondensation, the elongate sperm nucleus changes shape, forming a spherical male pronucleus, which attains the size of the female pronucleus. Cleavage begins immediately after pronuclear fusion.
The ultrastructure of oncospheral hook formation in the anoplocephalid cestode Mosgovoyia ctenoides (Railliet, 1890) Beveridge, 1978, is described. The hook morphogenesis takes place inside the six symmetrically arranged hook-forming cells, the oncoblasts. They show characteristic large nuclei of semilunar shape, localized at one pole of the embryo. At the beginning of the hook formation, the "hook-forming centre" appears in the cytoplasmic part of each oncoblast. It consists of numerous free ribosomes and polyribosomes surrounded by several mitochondria and Golgi complexes. The hook-forming centre is involved in synthesis of an electron-dense, undifferentiated hook primordium, which undergoes progressive differentiation and elongation into the fully developed hook. A fully formed oncospheral hook consists of the three parts: blade, shank, and base. Each hook, at the site of its protrusion from the oncosphere, is surrounded by two electron-dense rings interconnected by a circular septate junction. The hook material consists of two or three layers that differ in electron density: (1) a moderately electron-dense core, (2) a middle layer of low electron density, and (3) a highly osmiophilic cortex. Wide bands of hook muscles are attached to the basal and collar parts of the hook. The hook blades project outside of the oncospheral body into a large cavity delimited by the hook region membrane attached at this pole directly to the oncospheral surface. In the fully developed oncosphere of M. ctenoides, the three pairs of oncospheral hooks and their muscles form a complex "hook muscle system", responsible for coordinated hook action. The differentiation and ultrastructure of oncospheral hooks in the oncospheres of M. ctenoides are compared to those described in other cestode species.
This study was performed to determine the tapeworm infection of grazing cattle in 11 dairy herds in Lower Silesia and Lesser Poland (Galicia). Rectal faecal samples were examined microscopically for tapeworm eggs by Willis-Shlaaf’s flotation, Telemann’s sedimentation (for fatty stools) and decantation method. Out of 182 cattle, 10 (5.5%) were found to be infected with tapeworms. The prevalence in 5 of 11 examined herds varied from 15.5 to 30.5% and was highest for animal being in the first lactation. Tapeworm eggs were detected in animals being in the first and second lactation (about three- to four-years-old cows). All the qualitative methods were effective in the diagnosis of tapeworm infection in cattle.
Mathevotaenia panamaensis sp. nov. (Cestoda, Anoplocephalidae, Linstowiinae) from a green spiny lizard, Sceloporus malachiticus, collected in Panama is described. This is the first species of Mathevotaenia reported from a lizard host. The new species is most similar to Mathevotaenia bivittata in that mature eggs are concentrated along the lateral margins of the proglottids. Major differences between the two species include oval cirrus sac in M. bivittata, a spherical cirrus sac in M. panamaensis; ovary compact consisting of 10–15 short lobules in M. bivittata, ovary bilobed with each lobe consisting of 3–4 lobules in M. panamaensis.
Paranoplocephala kalelai (Tenora, Haukisalmi et Henttonen, 1985) is an anoplocephalid cestode that primarily parasitizes the grey-sided vole Myodes rufocanus (syn. Clethrionomys rufocanus) in northern Fennoscandia. In a preliminary molecular phylogenetic analysis, the cytochrome oxidase I (mtDNA) sequences of P. kalelai formed two divergent sublineages originating from two different localities in northern Finland and northern Norway. The present data confirm the existence of two strongly supported clades and show that their geographic distributions are overlapping in northernmost Finland. Relatively deep genetic divergence and coexistence of the two main clades at one of the localities suggest that the material may include two biological species. However, because the specimens representing the two mtDNA clades of P. kalelai are not morphometrically sufficiently differentiated and because the mtDNA clade of the specimens from the type locality is unknown, they are not assigned to different species. Comparison with the existing phylogeographic data of M. rufocanus suggests that the genetic structure of this host-specific cestode reflects the glacial and post-glacial history of its primary host. A redescription is presented for P. kalelai.
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.
This study reviews the taxonomy of anoplocephaline cestodes of wood rats, Neotoma cinerea, N. fuscipes and N. mexicana (Sigmodontinae) in the western and south-western U.S.A. The anoplocephaline fauna included five species, only one of which, Andrya neotomae Voge, 1946, was relatively common and occurred in all three host species. Other species were Paranoplocephala freemani Haukisalmi, Henttonen et Hardman, 2006, P. primordialis (Douthitt, 1915), both host-generalist species of North American rodents, and two apparently undescribed species of Paranoplocephala s. str. Aprostatandrya octodonensis Babero et Cattan, 1975 from the indigenous South American rodent Octodon degus is regarded as a junior synonym of A. neotomae. A redescription is provided for A. neotomae.
The cellular organisation of the infective eggs of I. madagascariensis has been reconstructed at light (LM) and electron microscopy (EM) level from serial semithin (LM) and ultrathin sections (EM). The oncospheres are surrounded by parenchymatic capsules. The total number of oncospheral cells' is about 44 (50 nuclei). Among them, five major cell types have been distinguished. These consisted of: (1) a six-nucleate, U-shaped penetration gland; (2) a bi-nucleate medullary centre (= sunken perikaryon of oncospheral tegument); (3) two nerve cells of neurosecretory type; (4) about 30 somatic cells (= myocytons of hook and somatic musculature); and (5) about 12 germinative cells (two groups of 6 cells), localised in the posterior pole of the hexacanth. The functional ultrastructure of hook-muscle system and penetration gland and their role in host tissue penetration are discussed.
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