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Several Taxa (several + taxa)
Selected AbstractsBeiträge zur Pilzflora von Mecklenburg-Vorpommern (Deutschland), 6.FEDDES REPERTORIUM, Issue 3-4 2007Folge Aus der Region Mecklenburg-Vorpommern (Nordostdeutschland) werden Funde von 89 Arten Macromyceten und phytoparasitischen Pilzen mitgeteilt. Einige Taxa werden erstmals für die Region nachgewiesen, einige andere nach Jahrzehnten wiedergefunden. Die Verbreitung von neun dieser Arten wird auf Rasterkarten dargestellt. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Contributions to the Fungus Flora of Mecklenburg-Vorpommern (Germany), part 6 From the region Mecklenburg-Vorpommern (northeastern Germany) new records of 89 species of macromycetes and phytoparasitic fungi are communicated. Several taxa are first records for this region, a few others were observed again after many years of failure. The distribution of nine of the mentioned species is shown on grid maps. [source] The evolution of the protonephridial terminal organ across Rotifera with particular emphasis on Dicranophorus forcipatus, Encentrum mucronatum and Erignatha clastopis (Rotifera: Dicranophoridae)ACTA ZOOLOGICA, Issue 2 2010Ole Riemann Abstract Riemann, O. and Ahlrichs, W.H. 2009. The evolution of the protonephridial terminal organ across Rotifera with particular emphasis on Dicranophorus forcipatus, Encentrum mucronatum and Erignatha clastopis (Rotifera: Dicranophoridae). ,Acta Zoologica (Stockholm) 91: 199,211 We report on the ultrastructure of the protonephridial terminal organ in three species of dicranophorid rotifers (Dicranophorus forcipatus, Encentrum mucronatum and Erignatha clastopis). Differences between the three species relate to shape and size, the morphology of the filter region and the number of microvilli and cilia inside the terminal organ. A comparison across Rotifera indicates that the terminal organs in D. forcipatus display a number of plesiomorphic characters, but are modified in E. mucronatum and Er. clastopis. This is in accordance with the results of phylogenetic analyses suggesting a basal position of D. forcipatus compared with the more derived species E. mucronatum and Er. clastopis. Moreover, we survey available data on the terminal organ in Rotifera and discuss its evolutionary transformations. The protonephridial terminal organ in the common ancestor of Rotifera consisted of a cytoplasmic cylinder with cilia united into a vibratile flame and a single circle of circumciliary microvilli. Depending on the topology on which characters are optimized, the site of ultrafiltration was formed by longitudinal cytoplasmic columns spanned by a fine filter diaphragm or by pores in the wall of the terminal organ. In several taxa of Rotifera, the terminal organ , probably independently , lost its circumciliary microvilli. [source] Relative sensitivity distribution of aquatic invertebrates to organic and metal compoundsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2004Peter Carsten von der Ohe Abstract In the field, a multitude of species can be exposed to numerous toxicants; thus, the sensitivity of individual species to particular toxicants must be known to predict effects and to analyze changes in species composition. For most species, no information about their toxicant sensitivity is available. To address this limitation, we have grouped the available information to assign sensitivities to aquatic invertebrate taxa relative to Daphnia magna. With respect to organic compounds, most taxa of the orders Anisoptera, Basommatophora, Coleoptera, Decapoda, Diptera, Ephemeroptera, Eulamellibranchiata, Heteroptera, Hirudinea, Isopoda, Oligochaeta, Prosobranchia, Trichoptera, Tricladida, and Zygoptera are less sensitive than D. magna. Some taxa of the Amphipoda, Plecoptera, and Cladocera (other than D. magna) are significantly more sensitive. For organic compounds, approximately 22% of the investigated taxa were more sensitive than D. magna. Most taxa of the orders Amphipoda, Basommatophora, Diptera, Ephemeroptera, Eulamellibranchiata, Heteroptera, Isopoda, Oligochaeta, and Tricladida are significantly less sensitive than D. magna to metal compounds. The taxa belonging to the Crustacea, with the exception of the order Isopoda, are much more sensitive. For metal compounds, approximately 30% of the investigated taxa were more sensitive than D. magna. Hence, D. magna is among the most sensitive taxa regarding both groups of toxicants. The sensitivities for several taxa are listed, and use of the relative sensitivity distribution to link toxicant effects in mesocosm studies and field investigations is discussed. [source] Taxonomy, evolutionary History and Distribution of the middle to late Famennian Wocklumeriina (Ammonoidea, Clymeniida)FOSSIL RECORD-MITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE, Issue 1 2000R. Thomas Becker Abstract Old collections, new records, and data from global literature are used for taxonomic revisions and for a new reconstruction of the evolutionary history of the triangularly coiled clymenids, the Wocklumeriaceae, and their ancestors. Epiwocklumeria applanata is first reported from the topmost Wocklum Limestone at Hasselbachtal and Drewer, and this supports the distinction of an applanata Subzone just prior to the global Hangenberg Event which wiped out the whole group. The Wocklumeriaceae and Glatziellidae record of the famous Oberrödinghausen Railway Cut and of other Rhenish sections is revised. The Maïder of Southern Morocco has yielded first Parawocklumeria patens, paprothae, Wocklumeria sphaeroides plana, Kielcensia ingeniens n. sp., and Synwocklumeria mapesi n. sp. Parawocklumeria distributa Czarnocki forms the type-species of Tardewocklumeria n. gen. Lecto- and neotypes for several taxa are designated. The variability and paedomorphic patterns of Wo. sphaeroides are discussed. The Wocklumeriaceae represent the terminal Famennian (Upper Devonian VI-C/D) radiation of a long-ranging lineage which evolved in parallel to other clymenid groups. They are characterized by sutural features and by longidomic and very slowly expanding whorls. The polyphyletic traditional Gonioclymeniina are divided into the suborder Wocklumeriina (with Wocklumeriaceae, Glatziellaceae n.superfam. and Biloclymeniaceae) and into the Gonioclymeniaceae of the Clymeniina. Gyroclymenia Czarnocki is regarded as a junior synonym of Pleuroclymenia Schindewolf which, however, does not include the ,Pleuro.' americana and eurylobica groups. Pleuroclymenia represents the ancestral form of the Wocklumeriina and also the phylogenetical link with Platyclymenia (Varioclymenia) of the Clymeniaceae. The Gonioclymeniaceae had their roots in advanced Platyclymeniidae. Alte Aufsammlungen, Neunachweise und globale Literaturdaten werden für taxonomische Revisionen und für eine neue Rekonstruktion der Evolution der Dreiecksclymenien (Wocklumeriaceae) und ihrer Vorfahren benutzt. Epiwocklumeria applanata wird zum ersten Mal im Hasselbachtal und bei Drewer nachgewiesen, und diese Funde bestätigen die Abtrennung einer applanata -Subzone im unmittelbar Liegenden des Hangenberg-Event, welcher zum Aussterben der gesamten Gruppe führte. Die Verbreitung von Wocklumeriaceae und Glatziellidae im klassischen Profil des Bahneinschnittes bei Oberrödinghausen und an anderen Fundorten im Rheinischen Schiefergebirge wird revidiert. Der Maïder in Süd-Marokko lieferte erstmalig Parawocklumeria patens, paprothae, Wocklumeria sphaeroides plana, Kielcensia ingeniens n. sp. und Synwocklumeria mapesi n. sp. Parawocklumeria distributa Czarnocki bildet die Typus-Art von Tardewocklumeria n.gen. Weiterhin werden die Variabilität und paedomorphe Erscheinungen bei Wo. sphaeroides diskutiert. Die Wocklumeriaceae repräsentieren im höchsten Famennium (UD VI-C/D) die Radiationsphase einer langlebigen phylogenetischen Linie, die sich parallel zu anderen Clymenien entwickelte. Sie ist durch Suturmerkmale und lange Wohnkammern bei niedrigmündigen Gehäusen charakterisiert. Die als polyphyletisch erkannten Gonioclymeniina werden in die Wocklumeriina (mit Wocklumeriaceae, Glatziellaceae n.superfam. und Biloclymeniaceae) und in die Gonioclymeniaceae der Clymeniina geteilt. Gyroclymenia Czarnocki ist ein jüngeres Synonym von Pleuroclymenia Schindewolf, umfasst jedoch nicht die ,Pleuro.' americana -und ,Pleuro.' eurylobica -Artgruppen. Die Gattung ist die ursprünglichste Form der Wocklumeriina und stellt gleichzeitig das Bindeglied zu Platyclymenia (Varioclymenia) der Clymeniaceae dar. Die Gonioclymeniaceae wurzeln in fortgeschrittenen Platyclymeniidae. [source] Physiological constraints on contest behaviourFUNCTIONAL ECOLOGY, Issue 4 2007M. BRIFFA Summary 1Contests may involve injurious fighting, other types of direct physical aggression and communication. They occur over ownership access to mates and other resources that may increase an individual's attractiveness and its chance of survival. Traits that enhance resource holding potential may be the result of sexual selection, natural selection or a combination of both. 2Agonistic behaviours are expected to be demanding to perform and costly in terms of changes in physiological state. The ability to meet the physiological costs may determine contest outcomes and constrain the intensity of agonistic activities. 3The energetic costs have been investigated in a broad range of taxa using a variety of techniques. They include the mobilization of energy reserves, but a key cost in several taxa appears to be limited anaerobic capacity and subsequent accumulation of lactic acid. Androgens, stress hormones and neurohormones have also been shown to constrain fighting behaviour. However, due to key differences in the endocrine systems of vertebrates and invertebrates, the effects of hormones are far less consistent across taxa than in the case of metabolites. 4Physiological constraints on fighting may vary according to their importance relative to circumstantial costs, the time-scale over which they exert their effects, their effects on different roles and their causal links with behaviour. Incorporating these factors into theoretical studies of contest behaviour may give further insights of how the costs of fighting influence agonistic behaviour. [source] The kdr mutation occurs in the Mopti form of Anopheles gambiaes.s. through introgressionINSECT MOLECULAR BIOLOGY, Issue 5 2000M. Weill Abstract Anopheles gambiaes.s. is a complex of sibling taxa characterized by various paracentric inversions. In west and central Africa, where several taxa are sympatric, a kdr mutation responsible for pyrethroid resistance has been described in only one (the S taxon), suggesting an absence of gene flow between them. Following a thorough sampling, we have found a kdr mutation in another taxon (M). To establish whether this mutation is the same event or not, the large intron upstream of the kdr mutation was sequenced to find polymorphic sites in susceptible/resistant and M/S mosquitoes. The low genetic diversity found in this DNA region indicates that a local genetic sweep has recently occurred. However, some polymorphic sites were found, and it is therefore concluded that the kdr mutation in the M taxon is not an independent mutation event, and is best explained by an introgression from the S taxon. These results are discussed within the context of possible gene flow between members of An. gambiae s.s. taxa, and with the possible spread of the kdr mutation in other closely related malaria vectors of the An. gambiae complex. [source] Ultrastructure and development of forked and capillary setae in the polychaetes Orbinia bioreti and Orbinia latreillii (Annelida: Orbiniidae)INVERTEBRATE BIOLOGY, Issue 1 2001Bilke Hausam Abstract. Recent investigations into chaetogenesis of certain types of annelid setae provide important results for unravelling the phylogenetic relationships within several taxa of poly-chaetous annelids. This paper presents data on ultrastructure and development of 2 types of orbiniid setae. The analysis of the crenulate capillaries in Orbinia latreillii reveals a formation process which clearly differs from the development of Equisetum -like setae of lingulid bra-chiopods. For the investigation of forked setae, which up to now have been neglected in the discussion on the phylogenetic significance of annelid setae, notopodial setal sacs of O. latreillii and O. bioreti were studied by light- and electron microscopy. In the setal sacs, stages of forked setae are restricted to a dorsocaudal pouch, which represents the site of setal formation. The 2 diverging, stout tines of the fork bear spines on their inner margins, each of which is preformed by a single microvillus. After retraction of the microvilli, a characteristic pattern of the setal canals inside of the spines remains. The present study belongs to a series of comparative studies into chaetogenesis of forked setae. These special setae are also found in other orbiniid taxa as well as some paraonids, scalibregmatids, and nephtyids. Ultrastructural investigations into the development of these forked setae might suggest homology. [source] Indicators for biodiversity in agricultural landscapes: a pan-European studyJOURNAL OF APPLIED ECOLOGY, Issue 1 2008R. Billeter Summary 1In many European agricultural landscapes, species richness is declining considerably. Studies performed at a very large spatial scale are helpful in understanding the reasons for this decline and as a basis for guiding policy. In a unique, large-scale study of 25 agricultural landscapes in seven European countries, we investigated relationships between species richness in several taxa, and the links between biodiversity and landscape structure and management. 2We estimated the total species richness of vascular plants, birds and five arthropod groups in each 16-km2 landscape, and recorded various measures of both landscape structure and intensity of agricultural land use. We studied correlations between taxonomic groups and the effects of landscape and land-use parameters on the number of species in different taxonomic groups. Our statistical approach also accounted for regional variation in species richness unrelated to landscape or land-use factors. 3The results reveal strong geographical trends in species richness in all taxonomic groups. No single species group emerged as a good predictor of all other species groups. Species richness of all groups increased with the area of semi-natural habitats in the landscape. Species richness of birds and vascular plants was negatively associated with fertilizer use. 4Synthesis and applications. We conclude that indicator taxa are unlikely to provide an effective means of predicting biodiversity at a large spatial scale, especially where there is large biogeographical variation in species richness. However, a small list of landscape and land-use parameters can be used in agricultural landscapes to infer large-scale patterns of species richness. Our results suggest that to halt the loss of biodiversity in these landscapes, it is important to preserve and, if possible, increase the area of semi-natural habitat. [source] The flora of the South Sandwich Islands, with particular reference to the influence of geothermal heatingJOURNAL OF BIOGEOGRAPHY, Issue 6 2000P. Convey Abstract Aim, To carry out as comprehensive a survey as practicable of the flora (higher plants, mosses, liverworts, lichens, basidiomycete fungi and diatoms) of the isolated, volcanically active, South Sandwich Islands archipelago in the southern South Atlantic. To relate the components of this flora to (1) the influence of local geothermal heating and (2) wider regional floras. Location, South Sandwich Islands, southern South Atlantic Ocean, maritime Antarctic (56,60° S, 26,28° W). Methods, Ice-free accessible sites on all 11 of the major islands in the archipelago were visited by helicopter in January 1997. During each visit, voucher specimens of each floral group were collected. The comprehensiveness of collections obtained at each site varied with the duration of each visit (a function of tight logistic constraints) and extent of site. Visit duration varied from 1 to 9 h at most sites, with longer periods spent on Bellingshausen Island (2 days) and Leskov Island (1 day). Candlemas Island was examined in greater detail over a 4-week period in February 1997. At all sites, particular attention was given to areas influenced by geothermal heating. Results, Data obtained in 1997 are combined with updated records from the only previous survey (in 1964) to provide a baseline description of the flora of the archipelago, which currently includes 1 phanerogam, 38 mosses, 11 liverworts, 5 basidiomycete fungi, 41 lichenised fungi and 16 diatoms with, additionally, several taxa identified only to genus. Major elements of the moss and liverwort floras are composed of South American taxa (32% and 73%, respectively), with a further 45% of mosses having bipolar or cosmopolitan distributions. These two groups show low levels of Antarctic endemicity (11% and 18%, respectively). In contrast, 52% of lichens and 80% of basidiomycete fungi are endemic to the Antarctic. A further 36% of lichens are bipolar/cosmopolitan, with only 5% of South American origin. Main Conclusions, The flora of the South Sandwich Islands is clearly derived from those of other Antarctic zones. The flora of unheated ground is closely related to that of the maritime Antarctic, although with a very limited number of species represented. That of heated ground contains both maritime and sub-Antarctic elements, confirming the importance of geothermal heating for successful colonisation of the latter group. The occurrence of several maritime Antarctic species only on heated ground confirms the extreme severity of the archipelago's climate in comparison with well-studied sites much further south in this biogeographical zone. [source] Recent invasion of the tropical Atlantic by an Indo-Pacific coral reef fishMOLECULAR ECOLOGY, Issue 13 2005LUIZ A. ROCHA Abstract The last tropical connection between Atlantic and Indian,Pacific habitats closed c. 2 million years ago (Ma), with the onset of cold-water upwelling off southwestern Africa. Yet comparative morphology indicates more recent connections in several taxa, including reef-associated gobies (genus Gnatholepis). Coalescence and phylogenetic analyses of mtDNA cytochrome b sequences demonstrate that Gnatholepis invaded the Atlantic during an interglacial period ,145 000 years ago (d = 0.0054), colonizing from the Indian Ocean to the western Atlantic, and subsequently to the central (,100 000 years ago) and eastern Atlantic (,30 000 years ago). Census data show a contemporary range expansion in the northeastern Atlantic linked to global warming. [source] Mitochondrial DNA sequences support allozyme evidence for cryptic radiation of New Zealand Peripatoides (Onychophora)MOLECULAR ECOLOGY, Issue 3 2000S. A. Trewick Abstract A combination of single-strand conformation polymorphism analysis (SSCP) and sequencing were used to survey cytochrome oxidase I (COI) mitochondrial DNA (mtDNA) diversity among New Zealand ovoviviparous Onychophora. Most of the sites and individuals had previously been analysed using allozyme electrophoresis. A total of 157 peripatus collected at 54 sites throughout New Zealand were screened yielding 62 different haplotypes. Comparison of 540-bp COI sequences from Peripatoides revealed mean among-clade genetic distances of up to 11.4% using Kimura 2-parameter (K2P) analysis or 17.5% using general time-reversible (GTR + I + ,) analysis. Phylogenetic analysis revealed eight well-supported clades that were consistent with the allozyme analysis. Five of the six cryptic peripatus species distinguished by allozymes were confirmed by mtDNA analysis. The sixth taxon appeared to be paraphyletic, but genetic and geographical evidence suggested recent speciation. Two additional taxa were evident from the mtDNA data but neither occurred within the areas surveyed using allozymes. Among the peripatus surveyed with both mtDNA and allozymes, only one clear instance of recent introgression was evident, even though several taxa occurred in sympatry. This suggests well-developed mate recognition despite minimal morphological variation and low overall genetic diversity. [source] Lack of discontinuous gas exchange in a tracheate arthropod, Leiobunum townsendi (Arachnida, Opiliones)PHYSIOLOGICAL ENTOMOLOGY, Issue 2 2002John R. B. Lighton Abstract The discontinuous gas exchange cycle, characterized by stringent spiracular control and periods of near-zero external CO2 emission separated by ,bursts' of CO2 emission, has evolved independently in several taxa of tracheate arthropods. These include the hexapoda, diplopoda, and several arachnid taxa; ticks, pseudoscorpions and solphugids. This paper presents the first data on gas exchange kinetics in a harvestman (Arachnida; Opiliones). The experimental animal, Leiobunum townsendi Weed, from an arid area of the south-western United States, displayed a metabolic rate similar to those of other arthropods at 25 °C (129 ± 22 µW). Their CO2 emission kinetics showed, when the animals were motionless, only minor variations about a mean value of 0.0217 ± 0.0037 mL/h (n = 6, mean body mass 86 mg). Expressed on an intra-recording basis, the coefficient of variation of CO2 emission (= SD/MEAN), which is an index of short-term gas emission fluctuations and thus of spiracular control, had a mean value of only 0.082. In contrast, the coefficient of variation of animals employing a discontinuous gas exchange cycle is >,1.5. Gas exchange in opilionids, unlike the case with most other tracheate arthropods, may therefore be dominated by simple diffusion without a prominent role for wide modulations of spiracular conductance. Contributory to this conservative spiracular control strategy may be the weak degree of tracheation in opilionids, combined with circulating haemocyanin, which acts as both a transport medium and a buffering reservoir for respiratory gas exchange. [source] Ultrastructural Description of Breviata anathema, N. Gen., N. Sp., the Organism Previously Studied as "Mastigamoeba invertens"THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2006GISELLE WALKER ABSTRACT. An understanding of large-scale eukaryotic evolution is beginning to crystallise, as molecular and morphological data demonstrate that eukaryotes fall into six major groups. However, there are several taxa of which the affinities are yet to be resolved, and for which there are only either molecular or morphological data. One of these is the amoeboid flagellate Mastigamoeba invertens. This organism was originally misidentified and studied as a pelobiont using molecular data. We present its first light microscopical and ultrastructural characterisation. We demonstrate that it does not show affinities to the amoebozoan pelobionts, because unlike the pelobionts, it has a double basal body and two flagellar roots, a classical Golgi stack, and a large branching double membrane-bound organelle. Phylogenetic analyses of small subunit ribosomal RNA suggest an affinity with the apusomonads, when a covariotide correction for rate heterogeneity is used. We suggest that previous molecular results have been subject to artefacts from an insufficient correction for rate heterogeneity. We propose a new name for the taxon, Breviata anathema; and the unranked, apomorphy-based name "Breviates" for Breviata and its close relatives. [source] Sperm-limited fecundity and polyandry-induced mortality in female nematodes Caenorhabditis remaneiBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2010S. ANAID DIAZ In many sexually reproducing species, females are sperm limited and actively mate more than once which can lead to sperm competition between males. However, the costs and benefits of multiple matings may differ for males and females leading to different optimal mating frequencies and consequent sexual conflict. Under these circumstances, male traits that reduce females' re-mating rates are likely to evolve. However, the same traits can also reduce, directly or indirectly, female survival and/or manipulate female fecundity. Evidence of this sexual conflict is common across several taxa. Here, we examine the evidence for this form of conflict in the free-living nematodes of the Caenorhabditis genus. Members of this group are extensively used to describe developmental and physiological processes. Despite this, we understand little about the evolution of selfing, maintenance of males and sexual conflict in these species, particularly those with gonochoristic mating strategies. In this study, we demonstrate experimentally sexual conflict in the gonochoristic of C. remanei cultured under laboratory conditions. In our first experiment, we found that female fecundity increased with the number of males present which suggests that females' reproduction may be sperm limited. However, increasing the number of males present also reduced female survival. A second experiment ruled out the alternative explanation of density-dependent reduction in female survival when more males were present as increasing female density correspondingly did not affect female survival. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99, 362,369. [source] Multivariate analysis of leaf shape patterns in Asian species of the Uvaria group (Annonaceae)BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2003CONOR MEADE Multivariate analysis of leaf radian measurements was used to investigate variation in leaf shape among 34 Asian species of the Uvaria group, a large palaeotropical group of climbing Annonaceae characterized by imbricate petals and stellate hairs. Raw data were normalized by conversion into 15 ratio characters and using the log10 transformation. All species surveyed showed a unique leaf-shape ,bauplan'. The ratio character with the greatest discriminating power in both the Principal Components Analysis and Discriminant Analysis (DA) results was a measure of the shape of the leaf base. Ratio characters with the highest factor loadings for principal components 1 and 2 clearly separated the sampled taxa when plotted against one another and provided support for the retention of several taxa as distinct species or varieties. Classification of cases into taxa using DA yielded a correct classification rate of only 52% for the ratio-transformed data; however, division of taxa in the dataset into smaller subgroups defined by discrete morphological characters significantly increased the accuracy of case identification to between 67 and 100% of cases correctly classified, depending on the group. Case identification using DA on log10 -transformed data was higher than for the ratio values in the entire dataset (61.7%) and the larger subgroups. However, the rate of correct case assignment was lower in the smaller groups than for the ratio data. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 143, 231,242. [source] | ||||||||||||||||||||||