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Special Collections - Eleventh International Symposium on Flatworm Biology

Mostrando recursos 1 - 14 de 14

  1. When names are wrong and colours deceive: unravelling the Pseudoceros bicolor species complex (Polycladida)

    Litvaitis, Marian K.; Bolaños, D. Marcela; Quiroga, Sigmer Y.
    The polyclad Pseudoceros bicolor derives its name from a distinctive two-coloured dorsal colouration, which consists of a very dark, almost black central area with acute black lobes extending towards a translucent greyish margin. At least three different colour morphs have been described, ranging from a pale speckled brown through an evenly dark brown form, to a morphotype resembling the original species description. Pseudoceros aureolineatus is easily confused with the light brown colour morph of P. bicolor, and P. rawlinsonae resembles both P. bicolor and P. aureolineatus. Using morphological characters of newly collected specimens and nucleotide sequences of the 28S ribosomal...

  2. Establishing a flatworm ageing model

    Mouton, Stijn; Verdoodt, Freija; Willems, Maxime; Dhondt, Ineke; Crucke, Jeroen; Braeckman, Bart P.; Houthoofd, Wouter

  3. First report of two monogenean parasites (Calydiscoides sp. and Encotyllabe sp.) from Lethrinus nebulosus in the Persian Gulf.

    Jafari, Neda; Pazooki, Jamileh
    The family Lethrinidae is present in the north of the Persian Gulf and consists of four species, all members of the genus Lethrinus Cuvier, 1829. In this study, we performed a survey of monogenean fauna of Lethrinus nebulosus (Forsskål, 1775), locally called she’ri, a commercial marine fish species in south of Iran. Specimens of L. nebulosus were caught with trawl net, then taken to the laboratory. Seventy fish were measured and weighed. Gills were extracted and frozen for future examination.

  4. Parasites of coral reef fish: how much do we know? With a bibliography of fish parasites in New Caledonia

    Justine, Jean-Lou
    A compilation of 107 references dealing with fish parasites in New Caledonia permitted the production of a parasite-host list and a host-parasite list. The lists include Turbellaria, Monopisthocotylea, Polyopisthocotylea, Digenea, Cestoda, Nematoda, Copepoda, Isopoda, Acanthocephala and Hirudinea, with 580 host-parasite combinations, corresponding with more than 370 species of parasites. Protozoa are not included. Platyhelminthes are the major group, with 239 species, including 98 monopisthocotylean monogeneans and 105 digeneans. Copepods include 61 records, and nematodes include 41 records. The list of fish recorded with parasites includes 195 species, in which most (ca. 170 species) are coral reef associated, the rest being...

  5. Distribution of proliferating cells and vasa-positive cells in the embryo of Macrostomum lignano (Rhabditophora, Platyhelminthes)

    Willems, Maxime; Couvreur, Marjolein; Boone, Mieke; Houthoofd, Wouter; ARTOIS, Tom
    The neoblast stem cell system of flatworms is considered to be unique within the animal kingdom. How this stem cell system arises during embryonic development is intriguing. Therefore we performed bromodeoxyuridine labelling on late stage embryos of Macrostomum lignano to assess when the pattern of proliferating cells within the embryo is comparable to that of hatchlings. This pattern can be found in late embryonic stages (stage 8). We also used the freeze cracking method to perform macvasa embryonic labelling. Macvasa is a somatic and germ line stem cell marker. We showed macvasa protein distribution during the whole embryonic development. In...

  6. Planarian regeneration in the absence of a blastema

    Orii, Hidefumi
    During planarian regeneration, a new tissue called the blastema is formed after amputation and is thought to play an important role in pattern formation. To investigate its role, posterior fragments with irradiated stumps were generated by regional X-irradiation, followed by amputation. No blastema formation occurred in the irradiated fragments until 3 days after amputation, because all the neoblasts had been depleted from the stump area by irradiation. However, regeneration of the pharynx occurred in the predicted region of the fragment, even in the absence of a blastema. These results suggest that the blastema is not essential for pattern formation during...

  7. Characterization of hsp genes in planarian stem cells

    Conte, Maria; Deri, Paolo; Isolani, Maria Emilia; Mannini, Linda; Batistoni, Renata
    Planarians are a model system known for regenerative potential, body plasticity and continuous turnover of all differentiated cell types. These characteristics are based on the presence of pluripotent stem cells, called neoblasts. Damage or reduction in the number of neoblasts deeply affects planarian regeneration and survival. Heat shock proteins (HSPs) are known to perform essential cytoprotective functions in all organisms. To investigate the potential role of hsp-related genes on the dynamics of planarian stem cells, representative hsp-related genes were identified and characterized in normal conditions and after different stress stimuli. Our work revealed that two different hsp genes (Djhsp60 and...

  8. The pattern of FMRFamide and serotonin immunoreactive elements in the nervous system of Aspidogaster conchicola K. Baer, 1827 (Aspidogastrea, Aspidogastridae)

    Tolstenkov, Oleg; Terenina, Nadezhda; Kreshchenko, Natalia; Gustafsson, Margaretha
    The patterns of the neuropeptide FMRFamide and serotonin (5-HT) immunoreactive (IR) elements in the nervous system of Aspidogaster conchicola (Aspidogastrea, Aspidogastridae) are described using immunocytochemistry and confocal scanning laser microscopy. Both FMRFamid and 5-HT immunoreactivities occur in the bilobed brain, the three pairs of longitudinal nerve cords and many transverse commissures. The adhesive disc is strongly innervated by FMRFamide-IR nerve fibres. Many 5-HT-IR neurones were observed on the reproductive organs.

  9. Replication of basal bodies during ciliogenesis in the epidermis of Prolecithophora and Lecithoepitheliata (Plathelminthes)

    Drobysheva, Irina M.
    Centriologenesis has been little studied in the Plathelminthes. Taking into account the importance of ultrastructural features for phylogenetic reconstructions, we studied the development of cilia in mature turbellarians Friedmaniella sp. (Prolecithophora), Geocentrophora wagini, and Geocentrophora intersticialis (Lecithoepitheliata) to compare the events of centriolo- and ciliogenesis in their epidermis. In all these species the formation of the multitude of centrioles follows the acentriolar pathway. In Friedmaniella sp., each centriole appears inside an individual filamentous accumulation. In G. wagini, the procentrioles arise in clusters of fibrous granules. Several procentrioles are usually produced in a separate cluster. Such a very big cluster of...

  10. Spermatogenesis and spermatozoon ultrastructure in Dugesia sicula Lepori, 1948 (Platyhelminthes, Tricladida, Paludicola)

    Charni, Mohamed; Ben Ammar, Aouatef; Habib Jaafoura, Mohamed; Zghal, Fathia; Tekaya, Saïda
    We examine for the first time spermatogenesis, spermiogenesis and spermatozoon ultrastructure in Dugesia sicula Lepori, 1948 a sexual and diploid planarian living in Tunisian springs. This TEM-study shows that early spermatids joined by cytophores have rounded nuclei. During spermiogenesis, a row of microtubules appears in the differentiation zone beneath the plasma membrane and close to the intercentriolar body, which consists of several dense bands connected by filaments. Two free flagella (9+1 configuration) grow outside the spermatid. An apical layer of dense nucleoplasm develops and the flagellum appear, facing in opposite directions before rotating to lie parallel to each other after...

  11. Exotic freshwater planarians currently known from Japan

    Sluys, Ronald; Kawakatsu, Masaharu; Yamamoto, Kiyohiko
    Biogeographical and taxonomic information on the four non-indigenous freshwater planarians of Japan is reviewed, viz. Dugesia austroasiatica Kawakatsu, 1985, Girardia tigrina (Girard, 1850), G. dorotocephala (Woodworth, 1897), and Rhodax evelinae? Marcus, 1947. The occurrence of Girardia dorotocephala in Japan is unequivocally demonstrated. New karyological data are presented for populations of D. austroasiatica (chromosome complement: 2x=16, 3x=24), G. tigrina ( 2x=16, 3x=24), and G. dorotocephala (2x=16). The following factors may have facilitated the introduction and subsequent geographical spread of exotic freshwater triclads in Japan: popularization of domestic tropical fish cultures, and culture of exotic aquatic animals for food.

  12. A new genus for seven Brazilian land planarian species, split off from Notogynaphallia (Platyhelminthes, Tricladida)

    Carbayo, Fernando
    Special attention is given to cephalic structures of a species complex within the Notogynaphallia (Platyhelminthes, Tricladida). Notogynaphallia muelleri is redescribed. The species possesses a cephalic musculo-glandular organ. Its glandular and muscular organization are similar to that previously observed in N. caissara and N. fita and to that herein described for N. abundans, N. ceciliae, N. ernesti, and N. graffi. Based on these unique cephalic specializations, a new genus is proposed for these seven species. Functionally, the musculo-glandular organ may be an adaptation for capturing and holding prey. KEY WORDS: Luteostriata gen. nov., Luteostriata muelleri, cephalic retractor muscle, mesenchymal musculature, Geoplaninae, Terricola.

  13. Land flatworm community structure in a subtropical deciduous forest in Southern Brazil

    Baptista, Vanessa A.; Leal-Zanchet, Ana Maria
    Due to their biological characteristics and habitat requirements, land planarians have been proposed as indicator taxa in biodiversity and conservation studies. Herein, we investigated spatial patterns of land flatworm communities in the three main existent vegetation types of the most significant remnant of the subtropical deciduous forest in south Brazil. The main questions were: (1) How species-rich is the study area? (2) How are community-structure attributes allocated in areas with distinct floristic composition? (3) What are the effects of soil humidity and soil organic matter content on flatworm abundance? (4) Are there seasonal differences regarding species richness? (5) Are the...

  14. Ultrastructure of germaria and vitellaria in Dugesia sicula Lepori, 1948 (Platyhelminthes, Tricladida, Paludicola)

    Charni, Mohamed; Ben Ammar, Aouatef; Habib Jaafoura, Mohamed; Zghal, Fathia; Tekaya, Saïda
    The female gonad of the diploid and sexual planarian Dugesia sicula Lepori, 1948 has been studied by means of transmission electron microscopy (TEM). The germaria consist of two ovaries occurring in the anterior body part behind the eyes. The vitellaria are composed of two lateral rows of vitelline follicles ranged dorsally and ventrally from the ovaries to the copulatory apparatus. During their growth, oocytes are provided with scattered residual yolk globules. The cytoplasm of maturing oocytes is filled with mitochondria, chromatoid bodies, Golgi complexes, RER, annulate lamellae and small yolk globules (2-3 μm in diameter) surrounded by a simple membrane,...

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