Search publications of the members of the Royal Belgian institute of natural Sciences
-
Description of two new species of Chaetogonopteron with a key to species of the Sympycnus- Chaetogonopteron complex (Diptera, Dolichopodidae, Sympycninae) in China
- Two new species of Chaetogonopteron from South China are described as new to science: Chaetogonopteron anae sp. n. and C. zhangae sp. n. A key is given for the males of the 28 species known in the Sympycnus- Chaetogonopteron complex in China.
-
Typhloplanoida (Platyhelminthes, Rhabdocoela) from New Caledonia and eastern Australia, with the description of six new taxa
- Thirteen species of Typhloplanoida from the Australian east coast and New Caledonia are reported, six of them new to science. Three of these new species are representatives of the Promesostomidae: Coronhelmis cuypersi new species, Coronhelmis novaecaledoniae new species, and Kymocarens kanakorum new species. Austradenopharynx reynaertsi new genus and species is a member of the Solenopharyngidae. Two species are placed within the Typhloplanidae: Kaitalugia lydieae new genus and species and K. falcata new species. Furthermore, new localities are given for Messoplana minuta, known from the Weddell Sea, Brinkmanniella palmata, occurring on the North American Pacific coast, the Swedish west coast and in the Black and Mediterranean Seas, Ceratopera axi, a cosmopolitan species, and Vauclusia conica and Pilamonila bimascula, two Australian species. For the sake of completeness, two more species of which insufficient material is available, are mentioned. A complete species list of all marine Typhloplanoida found in the region is given. © The Royal Society of New Zealand 2005.
-
New species of Hybos Meigen from Guangdong Province, South China (Diptera: Empididae)
- The following three new species of the genus Hybos Meigen, from Guangdong Province, China, are described as new to science: Hybos mangshanensis, H. nankunshanensis, H. xiaohuangshanensis. Their relationships with related species are discussed. Copyright © 2005 Magnolia Press.
-
Two new species of Hybos from Guangdong (Diptera: Empidoidea: Hybotinae)
- The following two species are described as new to science: Hybos curvatus sp. nov. and H. obtusatus sp. nov. An updated key to the species of the genus from Guangdong is presented.
-
A new species of Clinocera Meigen (Diptera: Empididae) from China
- Clinocera guangdongensis sp. n., a new aquatic dance fly of the subfamily Clinocerinae (Diptera, Empididae) is described from China. Relationships with other described species are discussed. The species of Clinocera from China are keyed. The biogeographic distribution of the genus in China is discussed. Copyright © 2005 Magnolia Press.
-
Two new species of Trichopeza Rondani (Diptera: Empididae) from South China, with a key to world species
- The following two species of the genus Trichopeza Rondani collected in Guangdong Province (South China) are described as new to science: Trichopeza sinensis new species, Trichopeza liliae new species. A key to the species of the world is presented. © National University of Singapore.
-
A new species of Chelifera Macquart, with a key to the species from China (Diptera: Empididae)
- Chelifera nanlingensis sp. n., a new aquatic dance fly of the subfamily Hemerodromiinae (Diptera, Empididae), is described from China. It is placed in the rhombicercus group of Wagner et al., 2004. A key to the species of Chelifera from China is presented. © 2005 Taylor & Francis.
-
Obliquity-dominated glacio-eustatic sea level change in the early Oligocene: Evidence from the shallow marine siliciclastic Rupelian stratotype (Boom Formation, Belgium)
- Our results prove that glacio-eustatic sea level oscillations in the early Oligocene were dominantly obliquity controlled with additional influence of the ∼100- and 405-kyr eccentricity cycles. This was derived from spectral analysis of resistivity records from an extended downhole section of the Boom Clay succession in Belgium, that reveals a prevailing obliquity control on the laterally persistent metre-scale alternations of shallow marine silt- and claystones in the Rupelian historical stratotype succession. These direct measurements of sea level variations in a shallow marine setting corroborate that variations with similar frequencies in benthonic oxygen isotope records from the open ocean indeed reflect, at least partly, ice volume change. A very tentative astronomical tuning has been established for the Boom Clay succession which awaits future confirmation with the addition of more accurate age calibration points. © 2007 Blackwell Publishing Ltd.
-
Upper Silurian to Middle Devonian conodont faunas from the Rabat-Tiflet area (Northwestern Moroccan Meseta)
- Conodont faunas are generally sparse in Pridoli to middle Givetian deposits from the Rabat-Tiflet area in the northwestern Moroccan Meseta. The Pridoli and Lochkovian rocks consist of dark platy limestones alternating with dark shales containing graptolites in some levels. In the overlying part of the succession carbonate rocks predominate with the development of reefoid limestones in the lower Givetian. The eosteinhornensis, sulcatus, dehiscens vel kitabicus, laticostatus/ inversus, partitus, ensensis, hemiansatus, timorensis and rhenanus/ varcus zones have been recognized by occurrence of the conodont index species. The first appearance of Belodella devonica, occurring together with the graptolite Monograptus uniformis is used as a regional index species for the base of the Devonian. The age of some levels in the succession were previously dated by graptolites, dacryoconarids and rare goniatites.
-
Phylogeny of European Dolichopus and Gymnopternus (Diptera: Dolichopodidae) and the significance of morphological characters inferred from molecular data
- Dolichopodidae (over 6000 described species in more than 200 genera) is one of the most speciose families of Diptera. Males of many dolichopodid species, including Dolichopus, feature conspicuous ornaments (Male Secondary Sexual Characters) that are used during courtship. Next to these MSSCs, every identification key to Dolichopus primarily uses colour characters (postocular bristles; femora) of unknown phylogenetic relevance. The phylogeny of Dolichopodidae has rarely been investigated, especially at the species level, and molecular data were hardly ever involved. We inferred phylogenetic relationships among 45 species (57 samples) of the subfamily Dolichopodinae on the basis of 32 morphological and 1415 nucleotide characters (810 for COI, 605 for Cyt-b). The monophyly of Dolichopus and Gymnoptermus as well as the separate systematic position of Ethiromyia chalybea were supported in all analyses, confirming recent findings by other authors based purely on morphology. Within Dolichopus, stable species groups could be assigned to four distinct categories on the basis of their statistical support in 7 phylogenetic analyses: (i) clades significantly supported in all analyses, (ii) clades supported in trees based on DNA and combined data, but only partly in morphological trees, (iii) clades significantly supported in trees based on DNA and combined data, but not in morphological trees, and (iv) clades consistently supported only in morphological trees. The phylogeny generated here provides a better understanding of the phylogenetic relevance of some debated morphological characters used for species and species-group characterizations in the most commonly used idenlification keys. In this respect, postocular bristle colour proved of little phylogenetic relevance since every group with species featuring black bristles also included species with partly yellow bristles. Entirely or partly infuscated femora explained the nodes of three stable species groups and even revealed an incorrect polarity of this morphological character in three species. Four of 6 complex MSSCs and 5 of 8 more common MSSCs were found consistently in further species groups.
-
Molecular systematics of Dolichopodidae (Diptera) inferred from COI and 12S rDNA gene sequences based on European exemplars
- With ∼7000 species in ∼220 genera, the Dolichopodidae is one of the most speciose families of Diptera. Though the family as such is well defined, knowledge on the internal phylogenetic relationships is generally poor and although authors of successive monographs and catalogues indifferently listed most genera in specific subfamilies, their decisions were rarely based on sound phylogenetic analyses and never on molecular data. In a first attempt to unravel the phylogeny of Dolichopodidae, a combined COI + 12S rDNA dataset (1199 characters) of 119 samples of 101 European species was used in Bayesian (BAY), neighbour joining (NJ) and weighted/unweighted maximum parsimony analyses (MP). At the subfamily level, our study supports the monophyly of Dolichopodinae, Sympycninae, and Hydrophorinae (including Machaerium Haliday, 1832). Ten (Campsicnemus Haliday, 1851, Chrysotus Meigen, 1824, Dolichopus Latreille, 1796, Gymnopternus Loew, 1857, Medetera Fischer von Waldheim, 1819, Poecilobothrus Mik, 1878, Rhaphium Meigen, 1803, Teuchophorus Loew, 1857, Sciapus Zeller, 1842, Syntormon Loew, 1857) of the 14 multispecies genera formed monophyletic assemblages in all analyses and relationships among Argyra Macquart, 1834 species were supported in most analyses. At the subgeneric level, seven of the nine stable species-groups in Dolichopus as established during previous research were supported in most analyses. The validity of the recent transfer of Hercostomus chrysozygos Wiedemann, 1817 to Poecilobothrus was clearly supported in all analyses. Within Argyra and Rhaphium, interspecific relationships reflected previously used subgeneric classifications (Lasiargyra Mik, 1878, Leucostola Loew, 1857 and Argyra s.s. in Argyra; Porphyrops Meigen, 1824, Rhaphium s.s. and Xiphandrium Loew, 1857 in Rhaphium). Further, subclades within Medetera corresponded to species-groups defined by other authors featuring a different morphology and ecology. Anepsiomyia flaviventris (Meigen, 1824) most probably does not belong to Sympycninae but its current position within Peloropeodinae could not be confirmed. © CSIRO 2007.
-
First insights into the biodiversity and biogeography of the Southern Ocean deep sea
- Shallow marine benthic communities around Antarctica show high levels of endemism, gigantism, slow growth, longevity and late maturity, as well as adaptive radiations that have generated considerable biodiversity in some taxa. The deeper parts of the Southern Ocean exhibit some unique environmental features, including a very deep continental shelf and a weakly stratified water column, and are the source for much of the deep water in the world ocean. These features suggest that deep-sea faunas around the Antarctic may be related both to adjacent shelf communities and to those in other oceans. Unlike shallow-water Antarctic benthic communities, however, little is known about life in this vast deep-sea region. Here, we report new data from recent sampling expeditions in the deep Weddell Sea and adjacent areas (748-6,348 m water depth) that reveal high levels of new biodiversity; for example, 674 isopods species, of which 585 were new to science. Bathymetric and biogeographic trends varied between taxa. In groups such as the isopods and polychaetes, slope assemblages included species that have invaded from the shelf. In other taxa, the shelf and slope assemblages were more distinct. Abyssal faunas tended to have stronger links to other oceans, particularly the Atlantic, but mainly in taxa with good dispersal capabilities, such as the Foraminifera. The isopods, ostracods and nematodes, which are poor dispersers, include many species currently known only from the Southern Ocean. Our findings challenge suggestions that deep-sea diversity is depressed in the Southern Ocean and provide a basis for exploring the evolutionary significance of the varied biogeographic patterns observed in this remote environment. ©2007 Nature Publishing Group.
-
Limitations on the application of the Devonian standard conodont zonation
- The most commonly used Lower and Middle Devonian conodont zonations that sometimes have been presented as standard zonations are evaluated. The author questions whether the Frasnian standard conodont zonation based on a phylogenetic succession of species belonging to the pelagic genera Mesotaxis, Palmatolepis and Siphonodella can be used for worldwide correlation. He favours the idea of an international conodont reference scale based on a synthesis of well established and documented conodont successions (with figured specimens of first and last occurrences of index-species) from key areas representing a variety of facies. Graphic correlation is likely to be the most objective and precise method to provide such a synthesis represented by the composite standard. Such standards have been already elaborated for the Frasnian and the Middle Devonian. This point of view does not imply that classical biozonations should be abandoned.
-
Ostracods and lithofacies of the Middle/Upper Devonian boundary stratotype (Puech de la Suque, Montagne Noire, France)
- This paper discusses ostracods and their environmental setting close to the Givetian/Frasnian boundary in the Puech de la Suque Global Stratotype Section and Point. The ostracod fauna belongs exclusively to the Eifelian mega-assemblage and is largely dominated by Podocopina instars. Consequently, the majority of the 33 species recognised and illustrated is described in open nomenclature. The abundance of instars also indicates that most of beds are related to storm deposition. The composition of the fauna suggests a regression in the late Givetian followed by a transgression at the beginning of the Frasnian. Only one ostracod assemblage collected in the upper part of the section indicates a deeper setting below the storm wave base. Eight taxa disappeared in two steps near the Givetian/Frasnian boundary, probably in relation to the Frasnes Event. The sedimentological analysis confirms that the section is constituted principally of storm deposits and reveals in addition the presence of numerous reddish hardgrounds highlighting an important condensation of the sequence.
-
Organic matter and dissolved inorganic nitrogen distributions in estuarine muddy deposits
- Organic matter (OM) and dissolved inorganic nitrogen (DIN: nitrite, nitrate and ammonium) in the sediments as well as in the water column of two temperate estuaries, the Scheldt Estuary in Belgium and the Netherlands, and the Fraser Estuary in Canada, were investigated. Three representative stations, differing in salinity and representing areas of fast sedimentation, were selected in each estuary. Samples were taken during periods of high and low river discharge. The results show, in both estuaries, that the vertical distributions of OM and DIN in a sediment layer are affected by the instability, caused by episodic resuspension and re-deposition, of the uppermost sediment layer. The findings of this study suggest a hypothesis, next to biogeochemical processes, that the OM and DIN distributions in upper sediment layers are influenced by sedimentary processes in the estuarine environment. The same sedimentary processes even in different estuaries affect OM and DIN distributions in an equivalent way. Correspondingly, the similarity or difference in OM and DIN distribution to a certain extent reflects the sedimentary dynamics. River runoff and sediment resuspension and sedimentation have important impacts on sediment behaviour and thus regulate OM and DIN distributions and shape their vertical profiles in the sediments. As a reflection, the coupling of sediment resuspension followed by redeposition can be deduced from the vertical profile of DIN in the bottom sediments which, in turn, can provide a time-integrated periodic record of the most recent sedimentary history. Copyright © 2007 AEHMS.
-
Diversity of rotifer fauna from five coastal peat swamps on phuket island, southern Thailand
- A total of 133 rotifer species was identified from five coastal peat swamps on Phuket Island. Of these, Dicranophoroides sp.A and Harringia rousseleti were new to Thailand. The most speciose genus was Lecane (30.82\%), followed by Lepadella (12.03\%). The highest species richness occurred in Jae-Son (100 species), followed byJik (84 species), Jood (67 species), Mai-Khao (65 species) and Sra-Boua (48 species), respectively. One hundred and ninety-three rotifer species are now known from peat swamps in Thailand.
-
Revision of the eurybrachidae (IX). The new oriental genus Nilgiribrachys (Hemiptera: Fulgoromorpha)
- The genus Nilgiribrachys Constant n. g. is described for a species from Southern India, Nilgiribrachys rubroviridis Constant n. sp. Illustrations, photos of habitus and a distribution map are provided with the description of the species. The suprageneric placement is dicussed and the new genus is provisionally placed in the tribe Loxocephalini Schmidt 1908.
-
Seasonal variability of suspended particulate matter observed from SeaWiFS images near the Belgian coast
- Suspended Particulate Matter (SPM) surface concentration maps in the Belgian/Dutch coastal zone are retrieved from SeaWiFS images and are corrected using in situ measurements to obtain depth-averaged SPM concentration maps. A spatial correlation analysis of the derived maps shows that the area could be divided into three subregions where the correlations between the SPM concentrations are higher than 70\%. Examination of in situ SPM concentration measurements reveals that during about 1/3 of the tidal cycle the SPM concentration is significantly higher than during the rest of the cycle. Strong vertical gradients are sometimes observed during periods with increased SPM concentration. A satellite image taken during such a period would underestimate the depth-averaged SPM concentration. Images taken during other periods better represents (except for some small corrections) the averaged SPM concentration. The methodology for obtaining the depth-averaged SPM concentration maps from surface SPM distributions derived from SeaWiFS images is positive but can be further improved. © 2007 Elsevier B.V. All rights reserved.
-
Ancient DNA reveals lack of postglacial habitat tracking in the arctic fox
- How species respond to an increased availability of habitat, for example at the end of the last glaciation, has been well established. In contrast, little is known about the opposite process, when the amount of habitat decreases. The hypothesis of habitat tracking predicts that species should be able to track both increases and decreases in habitat availability. The alternative hypothesis is that populations outside refugia become extinct during periods of unsuitable climate. To test these hypotheses, we used ancient DNA techniques to examine genetic variation in the arctic fox (Alopex lagopus) through an expansion/contraction cycle. The results show that the arctic fox in midlatitude Europe became extinct at the end of the Pleistocene and did not track the habitat when it shifted to the north. Instead, a high genetic similarity between the extant populations in Scandinavia and Siberia suggests an eastern origin for the Scandinavian population at the end of the last glaciation. These results provide new insights into how species respond to climate change, since they suggest that populations are unable to track decreases in habitat availability. This implies that arctic species may be particularly vulnerable to increases in global temperatures. © 2007 by The National Academy of Sciences of the USA.
-
The who, what and where of longidoridae and trichodoridae
