37 research outputs found

    Annotated catalogue of Porifera type specimens in the Belgian national collections

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    The national zoological collections of Belgium house 161 type specimens representing a total of 64 nominal species of Porifera. A list of extant and lost specimens is provided, presenting their original name, synonyms, museum characteristics and bibliography

    A new deep sea coralline sponge from Turks and Caicos Islands: <i>Willardia caicosensis</i> gen. <i>et</i> sp. nov. (Demospongiae: Hadromerida)

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    A new coralline sponge, Willardia caicosensis, assigned to the family Timeidae, is described from the deep fore reef off the Turks & Caicos Islands, tropical western Atlantic Ocean, where it is common at depths ranging from 100 to 119 m. Individuals vary up to 15-20 cm in width. The relatively thin aragonitic skeleton is covered with delicate pillars up to + 1 mm. The living tissue is restricted to the spaces between pillars and a thin sheet lying above the calcareous skeleton. Exhalant canals converge upon regularly spaced central oscules on the sponge surface. Siliceous spicules include tylostyles and amphiasters which are secondarily embedded in the aragonitic moiety of the skeleton. In addition, ultrastructural characters of thechoanocytes, such as periflagellar sleeves are typical of the Order Hadromerida. Two types of cells with dense spherules are abundant in the mesohyl: sperulous cells packed with large heterogeneous inclusions, protruding at the surface of the sponge, and glycocytes with smaller ovoid corpuscles, mainly grouped along the basal calcareous skeleton. Rough collagen fibrils extend in tracts from the base of the sponge to the ectosome. Sparse bacteria are scattered in the mesohyl

    Growth rate and chemical features of the massive calcium carbonate skeleton of <i>Petrobiona massiliana</i> (Baeriida: Calaronea: Calcispongiae)

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    In addition to the spicules typically produced by sponges, about twenty hypercalcified species belonging to both classes Demospongiae and Calcispongiae secrete a massive basal calcareous skeleton composed of calcite or aragonite. Skeletal growth rates and growth mechanisms are still poorly known in those hypercalcified Calcispongiae. In situ calcein staining experimentation on the Mediterranean calcisponge Petrobiona massiliana revealed a mean annual growth rate of the massive skeleton of 236 ”m/y (+/-90). Scanning electron microscopy (SEM) revealed that some spicules are entrapped within the massive skeleton (a solid mass forming apical crests with multidirectional growth axes) during its formation. Whole actines were observed within the massive skeleton of fractured specimens, indicating that they do not dissolve after entrapping Calcein incorporation bands seen through epifluorescence microscopy and SEM morphological observations of the skeletal surface revealed cone shaped protuberances corresponding to active growth areas A spatially discontinuous growth was highlighted, but the annual growth rates were similar at the tip of crests and at the bottom of depressions separating them The skeleton of P. massiliana is composed of magnesium calcite with strontium as the main trace element Significant differences in skeletal chemistry of specimens collected in different Mediterranean locations revealed a possible temperature dependence of Mg/Ca Although such temperature signature exists in the massive skeleton of P. massiliana, its use as an accurate environmental recorder is limited by several factors including multidirectional and spatially discontinuous growth

    Rates of apical septal extension of Desmophyllum dianthus: effect of association with endolithic photo-autotrophs

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    It has been hypothesized that endolithic photo- autotrophs inside the skeleton of cold-water corals may have a mutualistic relationship with the coral host posi- tively affecting coral calcification. This study investigated the effect of endolithic photo-autotrophs on the apical septal extension of the cold-water coral Desmophyllum dianthus at Fjord Comau, southern Chile (42.41°–42.15°S, 72.5°W). The fluorescent staining agent calcein was used to document the linear apical extension of septae for a period of one and a half years between 2006 and 2007. The results showed a severe reduction in extension rates asso- ciated with the presence of endolithic photo-autotrophs. Infested individuals grew about half as fast as non-infested polyps with a median value of 1.18 lm day-1 compared to 2.76 lm day-1. Contrary to the initial hypothesis, these results point toward a parasitic relationship between D. dianthus and its endolithic photo-autotrophs potentially impairing coral fitness. However, further data on physio- logical parameters and other aspects of the calcification process are necessary to confirm these findings

    Isoelectric focusing applied to taxonomic differentiation of the Trichophyton mentagrophytes complex and the related Trichophyton interdigitale36633

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    Somatic extracts from dermatophytes of the Trichophyton mentagrophytes complex and of Trichophyton interdigitale grown on trypticase soy broth were prepared for analytical isoelectric focusing in thin layer polyacrylamide gels over the pH range 4-6.5. A total of 44 strains were studied: 8 Arthroderma benhamiae (4 Americano-European and 4 African races), 4 Arthroderma vanbreuseghemii, 6 Trichophyton mentagrophytes and 26 Trichophyton interdigitale. Laser densitometric analysis revealed two outstanding clusters of profiles. The first one matched with the Arthroderma vanbreuseghemii profile and gathered all the Trichophyton interdigitale strains studied and 4 Trichophyton mentagrophytes. The second one corresponded to the Arthroderma benhamiae profile and gathered 2 Trichophyton mentagrophytes. This isoelectric focusing analysis suggests on one hand that Trichophyton interdigitale might be the anamorph species corresponding to the teleomorph Arthroderma vanbreuseghemii, and on the other hand that Trichophyton mentagrophytes might correspond to two teleomorph species, either Arthroderma vanbreuseghemii or Arthroderma benhamiae</p
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