Search publications of the members of the Royal Belgian institute of natural Sciences
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Field Method for testing Repellency of an Icaridin-Containing Skin Lotion against Vespid Wasps
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On a collection of Odonata from Cambodia, with the first record of Sinictionogomphus clavatus and a description of the female of Zyxomma breviventre
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Inter- and intraspecific variation in the surface pattern of the dermal bones of two sturgeon species
- Archaeological bone remains of sturgeon (Acipenser sturio/Acipenser oxyrinchus) from northwestern Europe are often identified to species on the basis of their surface morphology and then used to reconstruct the spatial distribution of the two species through time. The dermal bones of A. sturio are said to have an exterior surface pattern consisting of tubercles, while those of A. oxyrinchus are said to display alveoli. In the present paper, the validity of the surface pattern as a species-specific characteristic is critically assessed. To this purpose, dermal plates from modern, genetically identified museum specimens were studied and the surface morphology observed in a series of archaeological remains was compared with the genetic identifications obtained on these same remains. The analyses show that the surface pattern of dermal bones is related to the size of the individual, with the pattern of small A. oxyrinchus being similar to that of A. sturio. In addition, variations in the surface pattern among the bones of a single individual and within the same bone have been observed. These findings explain previous conflicting results between morphological and genetic identifications and allow the formulation of some recommendations for more accurate morphological identification of isolated archaeological sturgeon dermal bones.
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Mitogenomics reveals high synteny and long evolutionary histories of sympatric cryptic nematode species
- Species with seemingly identical morphology but with distinct genetic differences are abundant in the marine environment and frequently co-occur in the same habitat. Such cryptic species are typically delineated using a limited number of mitochondrial and/or nuclear marker genes, which do not yield information on gene order and gene content of the genomes under consideration. We used next-generation sequencing to study the composition of the mitochondrial genomes of four sympatrically distributed cryptic species of the Litoditis marina species complex (PmI, PmII, PmIII, and PmIV). The ecology, biology, and natural occurrence of these four species are well known, but the evolutionary processes behind this cryptic speciation remain largely unknown. The gene order of the mitochondrial genomes of the four species was conserved, but differences in genome length, gene length, and codon usage were observed. The atp8 gene was lacking in all four species. Phylogenetic analyses confirm that PmI and PmIV are sister species and that PmIII diverged earliest. The most recent common ancestor of the four cryptic species was estimated to have diverged 16 MYA. Synonymous mutations outnumbered nonsynonymous changes in all protein-encoding genes, with the Complex IV genes (coxI-III) experiencing the strongest purifying selection. Our mitogenomic results show that morphologically similar species can have long evolutionary histories and that PmIII has several differences in genetic makeup compared to the three other species, which may explain why it is better adapted to higher temperatures than the other species.
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Spatiotemporal variation and sediment retention effects on nematode communities associated with Halimeda opuntia (Linnaeus) Lamouroux (1816) and Sargassum polyceratium Montagne (1837) seaweeds in a tropical phytal ecosystem
- Nematodes play an important role in ecological processes and are one of the most abundant meiofaunal organisms associated with seaweeds. Yet, knowledge on seaweed bed ecosystems is limited. Nematodes associated with Sargassum polyceratium and Halimeda opuntia were compared in two transects, 80 m apart and parallel to the beach line in Cupe Beach, Brazil. The temporal variation during the dry and rainy seasons and the effect of sediment retention by the seaweed on nematode density and composition were investigated. The differences in nematode communities between the two seasons were mainly caused by the increase in density of the most abundant genera in the rainy season. A significant difference was observed between the nematode communities of the two transects for H. opuntia. The nematode communities of both seaweed species did not differ significantly in the same transect. The genus Euchromadora was dominant in both seaweed species. The amount of sediment retained by the seaweeds did not affect the overall nematode density. However, it was positively correlated with the density of Draconema and Euchromadora in both seaweeds, and both genera were exclusively found associated with seaweeds. This result opposes the idea that the more sediment retained by the seaweed, the higher the nematode overall density and the higher the number of nematodes originally coming from the sediment.
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Coexisting cryptic species of the Litoditis marina complex (Nematoda) show differential resource use and have distinct microbiomes with high intraspecific variability
- Differences in resource use or in tolerances to abiotic conditions are often invoked as potential mechanisms underlying the sympatric distribution of cryptic species. Additionally, the microbiome can provide physiological adaptations of the host to environmental conditions. We determined the intra- and interspecific variability of the microbiomes of three cryptic nematode species of the Litoditis marina species complex that co-occur, but show differences in abiotic tolerances. Roche 454 pyrosequencing of the microbial 16S rRNA gene revealed distinct bacterial communities characterized by a substantial diversity (85-513 OTUs) and many rare OTUs. The core microbiome of each species contained only very few OTUs (2-6), and four OTUs were identified as potentially generating tolerance to abiotic conditions. A controlled experiment in which nematodes from two cryptic species (Pm1 and Pm3) were fed with either an E. coli suspension or a bacterial mix was performed, and the 16S rRNA gene was sequenced using the MiSeq technology. OTU richness was 10-fold higher compared to the 454 data set and ranged between 1118 and 7864. This experiment confirmed the existence of species-specific microbiomes, a core microbiome with few OTUs, and high interindividual variability. The offered food source affected the bacterial community and illustrated different feeding behaviour between the cryptic species, with Pm3 exhibiting a higher degree of selective feeding than Pm1. Morphologically similar species belonging to the same feeding guild (bacterivores) can thus have substantial differences in their associated microbiomes and feeding strategy, which in turn may have important ramifications for biodiversity-ecosystem functioning relationships.
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Let the dead speak…comments on Dibble et al.'s reply to “Evidence supporting an intentional burial at La Chapelle-aux-Saints”
- In a reply to our paper presenting new evidence supporting an intentional Neanderthal burial at La Chapelle-aux-Saints (Corrèze, France), Dibble et al. (2014) reviewed our data in relation to the original Bouyssonie publications. They conclude that alternative hypotheses can account for the preservation of the human remains within a pit. Here we present new data from our recent excavations and highlight several misinterpretations of the Bouyssonie publications, which, when taken together refute most of their arguments. Moreover, we show that the different hypotheses proposed by Dibble et al. cannot work together and fail to provide a credible explanation for the deposit, reinforcing our demonstration that the burial hypothesis remains the most parsimonious explanation for the preservation of the Neanderthal skeletal material at La Chapelle-aux-Saints.
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Change in Historical Range of the Ural Owl in Europe
- A carpometacarpus recovered during archaeological excavations in the town of Quaregnon is the westernmost find ever reported in Europe of a Ural Owl (Strix uralensis), and the first occurrence for Belgium. Both the morphology of the skeletal element and its measurements rule out an identification as any of the other Strigiformes from the Western Palearctic. The provenance of this specimen, that dates to the medieval period (10th-12th centuries AD), is discussed. It is hypothesized that the bird was a wild animal, but the available evidence does not unequivocally determine whether it belonged to a local, breeding population that went extinct or if it came from a more distant population. However, a survey of other zooarchaeological finds of Ural Owl in Europe shows that the species occurred farther west in the past, outside the present natural breeding range. This suggests that Ural Owl may have found suitable nesting biotopes in Belgium and northern France during the medieval period.
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Toujours dans l’Ouest de l’Inde: une nouvelle faune de mammifères de l’Eocène inférieur dans la mine de lignite de Tadkeshwar
- Les mines de lignite de Vastan et Mangrol au Gujarat (ouest de l’Inde) ont livré une riche faune de vertébrés de l’Yprésien dont une proportion importante de mammifères de petite à moyenne taille d’affinité européenne. Nous présentons ici un nouvel assemblage contemporain issu de la mine voisine de Tadkeshwar. Deux couches fossilifères y ont été découvertes. La première est représentée par un chenal de sables argileux gris situé quelques mètres au-dessus du niveau de lignite inférieur de la mine. La seconde est représentée par un niveau lenticulaire de silts argileux foncés, ligniteux et riche en restes organiques, situé juste sous le niveau de lignite supérieur. Cette dernière couche est sédimentologiquement semblable aux célèbres lentilles fossilifères de Vastan. Ces deux niveaux à fossiles ont livrées une faune de mammifères similaire à celle de Vastan avec la présence du cambaytheriidé Cambaytherium thewissi, groupe frère des périssodactyles, des primates adapoïdes Marcgodinotius indicus et Asiadapis cambayensis, et du hyaenodontidé Indohyaenodon raoi. La présence de ces espèces dans les deux mines et dans différentes couches stratigraphiques suggère que les dépôts entre les deux niveaux à lignites représentent un seul et même âge à mammifères. Hormis les espèces classiques mentionnées ci-dessus, deux nouvelles espèces sont présentes. Un nouveau petit cambaytheriidé abondant est décrit sur base de mâchoires supérieures et inférieures, de nombreuses dents isolées et d’os postcrâniens. Un nouveau tillodonte esthonychidé est nommé sur base d’un dentaire avec m3 et d’incisives et molaires inférieures et supérieures isolées. Cette nouvelle faune de Tadkeshwar recèle également les premiers grands vertébrés de l’Eocène inférieur de l’Inde tels qu’un mammifère pantodonte appartenant probablement aux coryphodontidés, un crocodiliforme dyrosauridé et un serpent madtsoiidé géant. Parmi les vertébrés de Tadkeshwar plusieurs taxons sont d’affinité gondwanienne indiquant que l’Eocène inférieur était une période cruciale en Inde durant laquelle des taxons laurasiens d’affinité européenne coexistèrent avec des taxons reliques du Gondwana avant la collision avec l’Asie. Le travail de terrain est financé par la National Geographic Society, la Fondation Leakey et le Wadia Institute of Himalayan Geology. Ce résumé est une contribution au projet BR/121/A3/PalEurafrica financé par la Politique Scientifique Belge.
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Interaction between man and animals in the prehistoric Nile Valley
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Les serpents de l’Eocène inférieur de Tadkeshwar (Gujarat, Inde): un nouveau géant parmi les classiques
- La Formation de Cambay dans la mine de lignite de Vastan, au Gujarat (ouest de l’Inde) a livré une faune très diversifiée de serpents de l’Eocène inférieur. Parmi ceux-ci se trouvent les plus anciens cénophidiens colubroïdes. Récemment, un nouvel assemblage de serpents a été découvert dans la mine de Tadkeshwar, située à 10 km au Sud-Ouest de Vastan. Comme à Vastan, les spécimens de Tadkeshwar sont uniquement représentés par des vertèbres isolées. Plusieurs espèces sont communes avec Vastan comme le petit Madtsoiidae gen. et sp. indet. qui présente une carène hémale, le serpent aquatique palaeophiidé Palaeophis sp., le Boidae indet., ainsi que Thaumastophis missiaeni (Caenophidia incertae sedis). Cependant, les serpents les plus abondants à Tadkeshwar sont les madtsoiidés. Parmi eux, un nouveau taxon géant dont la plus grande vertèbre mesure 43 mm de large présente une morphologie similaire aux genres Madtsoia et Gigantophis. Il diffère toutefois de ces derniers par la présence d’une vertèbre comprimée dorso-ventralement présentant des cotyles et condyles de forme très ovale ainsi que par la présence d’une forte échancrure sur le bord postérieur de l’arc neural. L’axe principal des prézygapophyses est transverse en vue dorsale et en vue antérieure les parapophyses sont très développées et s’étendent latéralement au-delà des extrémités distales des prézygapophyses. La carène hémale est absente. Alors que la composition de la faune de Tadkeshwar, comme celle de Vastan, n’est pas sans rappeler celle de l’Eocène inférieur d’Europe, la présence de ce madtsoiidé géant suggère une origine paléogéographique gondwanienne. En effet, de tels madtsoiidés ne sont connus que du Crétacé Supérieur et du Paléogène inférieur d’Amérique du Sud, d’Afrique et du sous-continent Indien ainsi que du Paléogène supérieur et du Néogène d’Australie. L’assemblage de serpents de Tadkeshwar indique donc que les taxons laurasiens d’affinités européennes étaient encore mélangés avec des taxons reliques du Gondwana à l’Eocène inférieur, peu avant la collision Inde-Asie. Le travail de terrain est soutenu par la National Geographic Society, la Fondation Leakey et le Wadia Institute of Himalayan Geology. Ce résumé est une contribution au projet BR/121/A3/PalEurAfrica financé par la Politique Scientifique Belge.
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Scutes for sturgeon size reconstruction: traditional and geometric morphometric techniques applied to Acipenser sturio and A. oxyrinchus
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Cetacean paleobiology
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Note tassonomische au alcuni Trechus italiani del „gruppo subnotatus“ ‚sensu Jeannel, 1927), con rivalutazione di un taxon e una nuova sinonimia (Coleoptera, Carabidae, Trechinae)
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Archeologische opgraving van een midden- mesolithische tot midden-neolithische vindplaats te ‘Bazel-sluis 5’ (gemeente Kruibeke, provincie Oost-Vlaanderen)
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The Cerambycidae beetles fauna from the botanical garden Jean Massart (Brussels-Capital Region, Belgium)
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Description d'une nouvelle espèce de lobobunaea Packard, 1901 (Lepidoptera)
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Unraveling geological and geographical provenances of querns and mills during Roman times at the northern frontier of the Roman Empire (Belgium, Northern France, Southern Netherlands, Western germany): a multidisciplinary research project.
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Manufacture and diffusion of whetstones during Roman times in Northern Gaul (Belgium and Northern France).
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Geochemical sourcing of flint artifacts from Western Belgium and the German Rhineland: testing hypotheses on Gravettian period mobility and raw material economy
- Identifying the geological and geographical origin of lithic raw materials is critical to effectively address prehistoric forager raw material economies and mobility strategies. Currently, Paleolithic archaeology in Belgium lacks a systematic sourcing strategy to effectively substantiate detailed interpretations of prehistoric hunter-gatherer behavioral change across time and space. This pilot study evaluates the potential to “fingerprint” flint from the Mons Basin, western Belgium, using the laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) technique and a multivariate statistical analysis of 87 geological samples and 39 Gravettian period chipped stone artifacts. We reappraise two hypotheses raised by previous scholars based on visual raw material identification: (1) the Gravettian occupants of Maisières-Canal supplied themselves with “black flint” from one single source; (2) the sites Rhens and Koblenz-Metternich yielded artifacts indicative of long-distance transfer of western Belgian flint into the German Rhineland, ca. 260 km from the primary source area. Our results demonstrate the validity of LA-ICP-MS data with flint and compositional data analysis for fingerprinting discrete geological formations from the Mons Basin. We suggest multiple source provisioning for Maisières-Canal. Geochemical characterization of other potential flint sources is required to validate the long-distance transfer hypothesis of western Belgian “black flint” into the German Rhineland.
