Search publications of the members of the Royal Belgian institute of natural Sciences
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Endosymbiont dominated bacterial communities in a dwarf spider
- The microbial community of spiders is little known, with previous studies focussing primarily on the medical importance of spiders as vectors of pathogenic bacteria and on the screening of known cytoplasmic endosymbiont bacteria. These screening studies have been performed by means of specific primers that only amplify a selective set of endosymbionts, hampering the detection of unreported species in spiders. In order to have a more complete overview of the bacterial species that can be present in spiders, we applied a combination of a cloning assay, DGGE profiling and high-throughput sequencing on multiple individuals of the dwarf spider Oedothorax gibbosus. This revealed a co-infection of at least three known (Wolbachia, Rickettsia and Cardinium) and the detection of a previously unreported endosymbiont bacterium (Rhabdochlamydia) in spiders. 16S rRNA gene sequences of Rhabdochlamydia matched closely with those of Candidatus R. porcellionis, which is currently only reported as a pathogen from a woodlouse and with Candidatus R. crassificans reported from a cockroach. Remarkably, this bacterium appears to present in very high proportions in one of the two populations only, with all investigated females being infected. We also recovered Acinetobacter in high abundance in one individual. In total, more than 99% of approximately 4.5M high-throughput sequencing reads were restricted to these five bacterial species. In contrast to previously reported screening studies of terrestrial arthropods, our results suggest that the bacterial communities in this spider species are dominated by, or even restricted to endosymbiont bacteria. Given the high prevalence of endosymbiont species in spiders, this bacterial community pattern could be widespread in the Araneae order.
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Differentiation, selection and speciation in the salt marsh beetle Pogonus chalceus.
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The MODIRISK project: a large scaled survey on mosquito biodiversity as basis for risk assessment and control.
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Spider colonisation and source-sink effects in newly developed dunes and dikes along the river IJzer estuary.
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Patterns in speciation in wolf spiders from the Galapagos Archipelago: A case of ecological speciation?
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Notes on the beach-dwelling genus Chersodromia (Diptera: Hybotidae) from Tunisia: description of a new brachypterous species with notes on brachyptery in empidoids.
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Superfamily Empidoidea. Family Hybotidae.
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New and little-known species of the genus Tachydromia Meigen (Diptera, Hybotidae) from Thailand
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Divergence patterns of an adaptively radiated wolf spider genus on Galapagos
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The interaction of professional and non-professional entomologists in Flanders (Belgium): is this relationship really working.
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De Kesselberg binnenste buiten, een realisatie van Hona vzw
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Diep onder de Kesselberg: een half miljard jaar Leuvense geschiedenis in een notendop.
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In de Kesselberg: zeezand in een heuvel
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Vorming van de Kesselberg: over erosie, rivierterrassen, de Vlaamse Vallei, mammoeten en de mens.
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Erfgoed Aarde. Een kijk op mens en natuur vroeger en nu, een realisatie van Hona vzw
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De rol van de amateur
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Compilatie van de literatuur handelend over de spinnen van België verschenen in 2005 tot en met 2007.
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The virus vector family Trichodoridae (Nematoda), a source of many unknown cryptic species
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Craniodental and postcranial morphology of Indohyaenodon raoi from the Early Eocene of India, and its implications for ecology, phylogeny, and biogeography of hyaenodontid mammals
- New remains of the early Eocene hyaenodontid Indohyaenodon raoi are described from the Vastan Lignite Mine in Gujarat, western India, including the first known rostrum, upper dentition, and postcrania, substantially expanding our knowledge of the species and providing insights into its functional morphology and relationships. Craniodental morphology suggests that I. raoi had a broad diet, including non-vertebrate material as well as flesh of a diversity of prey species. Postcranial morphology is broadly similar to that of other early hyaenodontids and suggests a scansorial locomotor repertoire. Dental morphology indicates that I. raoi is closely related to other South Asian hyaenodontids, with shared features including strong cingula, narrow premolars, and a reduced P4 protocone. We present the most comprehensive phylogenetic analysis of Hyaenodontidae to date, which corroborates this relationship but finds South Asian hyaenodontids to be the stem of a group that includes most African hyaenodontids. This and other higher-level relationships within Hyaenodontidae are, however, weakly supported, and substantially different alternative hypotheses of relationships are not significantly less parsimonious, reflecting strong character conflict. Factors contributing to this conflict include the isolation of hyaenodontid faunas on different continents during much of the Eocene, canalization and simplification of carnivorous dentitions, and a lack of non-dental material for critical hyaenodontid groups. The new phylogeny is consistent with either an African or an Asian origin for the group.
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Red Iron-Pigmented Tooth Enamel in a Multituberculate Mammal from the Late Cretaceous Transylvanian “Haţeg Island”
- Mammals that inhabit islands are characterized by peculiar morphologies in comparison to their mainland relatives. Here we report the discovery of a partial skull associated with the lower jaws of a Late Cretaceous (~70 Ma) multituberculate mammal from the Carpathian “Haţeg Island” of Transylvania, Romania. The mammal belongs to the Kogaionidae, one of the rare families that survived the Cretaceous—Paleogene mass extinction in Europe. The excellent preservation of this specimen allows for the first time description of the complete dentition of a kogaionid and demonstration that the enigmatic Barbatodon transylvanicus presents a mosaic of primitive and derived characters, and that it is phylogenetically basal among the Cimolodonta. Another peculiarity is the presence of red pigmentation in its tooth enamel. The red coloration is present on the anterior side of the incisors and on the cusps of most of the teeth. Energy-dispersive X-ray spectrometry (EDS) analysis reveals that the pigmented enamel contains iron, as in living placentals. Such a red pigmentation is known in living soricine shrews and many families of rodents, where it is thought to increase the resistance of the enamel to the abrasion that occurs during “grinding” mastication. The extended pattern of red pigment distribution in Barbatodon is more similar to that in eulipotyplan insectivores than to that in rodents and suggests a very hard diet and, importantly, demonstrates that its grasping incisors were not ever-growing. As inferred for other endemic Transylvanian vertebrates such as dwarf herbivorous dinosaurs and unusual theropod dinosaurs, insularity was probably the main factor of survival of such a primitive mammalian lineage relative to other mainland contemporaries of the Northern hemisphere.
