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Allopodocotyle tunisiensis sp. nov. [Digenea, Opecoelidae], a parasite of Solea aegyptiaca [Teleostei, Soleidae] off Tunisia

100%

Derbel H. , Neifar L.

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tom 54

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nr 4

305-309

EN

Allopodocotyle tunisiensis sp. nov. is described from the intestine of Solea aegyptiaca Chabanaud collected from the Gulf of Gabès in the Mediterranean Sea off Tunisia. The new species belongs to the group C of Allopodocotyle Pritchard, 1966 species (sensu Bray 1987). It differs from its congeners in this group by the shape of the seminal vesicle and the anterior extend of the vitellarium which varies between just posterior to the ventral sucker and anterior margin. A key to the Allopodocotyle species of group C is presented. The status of the genera Allopodocotyle and Macvicaria (Gibson and Bray 1982) are briefly discussed.

2

First detailed data on metazoan parasites of the rare species short beaked garfish Belone svetovidovi (Teleostei: Belonidae) from Tunisian coast, Central Mediterranean Sea

80%

Chaari M. , Derbel H. , Neifar L.

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tom 62

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nr 1

EN

Forty five specimens of the short beaked garfish Belone svetovidovi, a rare belonid species largely confused with the garfish Belone belone from Tunisian coast Sea were examined for metazoan parasite. Nine metazoan parasites species were identified: one monogenean (Axine sp.), 4 digeneans (Lecithostaphylus retroflexus, Tergestia acanthocephala, Aponurus laguncula and Condylocotyla pilodora metacercaria), one copepod (Bomolochus bellones), one isopod (Irona nana), one acanthocephalan (Telosentis exiguus) and one nematod Hysterotylacium sp. Most of parasite species were new records for B. svetovidovi in Tunisia. In the parasite fauna of B. svetovidovi, digenean C. pilodora metacercaria was the most prevalent species (42%) followed by Monogenea Axine sp. (36%). The total length of the host did not influence parasitic infection in B. svetovidovi. The metazoan parasite composition of B. svetovidovi revealed great similarity than those of B. belone from Tunisia supporting same ecological behavior of both hosts.

3

Ultrastructural and cytochemical studies on vitellogenesis in the trypanorhynch cestode Parachristianella trygonis Dollfus, 1946 [Eutetrarhynchidae]

80%

Swiderski Z. , Miquel J. , Neifar L. , Mackiewicz J. S.

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nr 2

EN

During vitellogenesis in Parachristianella trygonis Trypanorhyncha, Eutetrarhynchidae) we distinguished four stages: (1) gonial or stem cell stage; (2) early differentiation stage concentrated on protein synthetic activity and shell-globule formation; (3) advanced differentiation stage with main cell activity concentrated on carbohydrate synthesis (glycogenesis) and massive glycogen storage in the form of α-glycogen rosettes and β-glycogen particles; and finally (4) mature vitellocyte stage. Early vitellocyte maturation is characterised by: (1) an increase in cell volume; (2) extensive development of large, parallel cisternae of GER that produce proteinaceous granules; (3) development of Golgi complexes engaged in packaging this material; (4) continuous enlargement of proteinaceous granules within vacuoles and their transformation into shell-globule clusters composed of heterogeneous material. Cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for polysaccharides indicated a strongly positive reaction for the presence of α-glycogen rosettes and β-glycogen particles in the advanced stage of vitellocyte maturation. Both protein synthesis for shell-globule formation and carbohydrate synthesis or glycogenesis, important storage of nutritive reserves for the developing embryos, observed during cytodifferentiation of P. trygonis vitellocytes overlap in time to some extent. Mature vitelline cells are very rich in three types of cell inclusions accumulated in large amounts in their cytoplasm: (1) shell-globule clusters, playing an important role in egg-shell formation; (2) numerous large lipid droplets, as well as a high accumulation of lipid and α-glycogen rosettes and β-glycogen particles that undoubtedly represent important nutritive reserves for the developing embryos. Despite the fact that the type of vitellogenesis and ultrastructure of the mature vitellocyte in P. trygonis appears to differ to some extent from those of three other trypanorhynch species, its general pattern and ultrastructure greatly resembles those observed in other lower cestodes. Factors that may have contributed to the qualitative and quantitative variation in lipids during vitellogenesis among the four species of Trypanorhyncha, are identified and discussed.

4

Ultrastructure of the spermatozoon of Macvicaria obovata (Digenea: Opecoelidae), a parasite of Sparus aurata (Pisces: Teleostei) from the Gulf of Gabes, Mediterranean Sea

71%

Kacem H. , Quilichini Y. , Neifar L. , Torres J. , Miquel J.

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nr 3

5

Ultrastructural and cytochemical studies on vitellogenesis in trypanorhynch cestode Dollfusiella spinulifera Beveridge, Neifar et Euzet, 2004 [Eutetrarhynchidae]

61%

Swiderski Z. , Miquel J. , Mlocicki D. , Neifar L. , Grytner-Ziecina B. , Mackiewicz J. S.

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nr 3

EN

The first description of vitellogenesis in the Trypanorhyncha is presented in this paper. Though the type of vitellogenesis and mature vitellocyte in Dollfusiella spinulifera appear to be unique among the Eucestoda, to some extent they resemble that observed in the lower cestodes, namely the Tetraphyllidea and Pseudophyllidea. Maturation is characterized by: (1) an increase in cell volume; (2) extensive development of large, parallel, frequently concentric cisternae of GER that produce proteinaceous granules; (3) development of Golgi complexes engaged in packaging this material; (4) continuous enlargement of proteinaceous granules within vesicles and their transformation into shell globule clusters; and (5) progressive fusion of all vesicles, with flocculent material containing the proteinaceous granules and shell globule clusters, into a single very large vesicle that characterises mature vitellocytes of this tapeworm. Cell inclusions in and around the large vesicle consist of flocculent material of a very low density, a few shell globule clusters, moderately dense proteinaceous granules and numerous large droplets of unsaturated lipids. A new previously unreported mode of transformation of proteinaceous granules into shell globule clusters, that evidently differs from that of pseudophyllideans and tetraphyllideans, is described. Cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for polysaccharides indicates a strongly positive reaction for membrane-bound glycoproteins in all membranous structures such as GER, mitochondria, Golgi complexes, nuclear and cell plasma membranes. Similar staining revealed β-glycogen particles scattered in the cytoplasm of maturing vitellocytes. Typical cytoplasmic β-glycogen particles appear mainly during early vitellocyte maturation but it is characteristic for this species that they are only seldom visible in mature cells. Some working hypotheses concerning the interrelationship between this particular pattern of vitellogensis, possible mode of egg formation in D. spinulifera, its embryonic development and trypanorhynchean life cycle, are drawn and discussed.