Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Genera

  • algal genus
  • ant genus
  • bacterial genus
  • common genus
  • cosmopolitan genus
  • different genus
  • diverse genus
  • dominant genus
  • endemic genus
  • extant genus
  • fossil genus
  • fungal genus
  • important genus
  • large genus
  • largest genus
  • many genus
  • monotypic genus
  • new genus
  • one genus
  • other genus
  • plant genus
  • relate genus
  • same genus
  • several genus
  • single genus
  • species-rich genus

  • Terms modified by Genera

  • genus Pseudomona
  • genus aspergillus
  • genus bacillus
  • genus drosophila
  • genus homo
  • genus lactobacillus
  • genus leishmania
  • genus level
  • genus mu

  • Selected Abstracts


    JOURNAL OF PHYCOLOGY, Issue 5 2009
    Sara M. Handy
    Dinoflagellates are a highly diverse and environmentally important group of protists with relatively poor resolution of phylogenetic relationships, particularly among heterotrophic species. We examined the phylogeny of several dinophysiacean dinoflagellates using samples collected from four Atlantic sites. As a rule, 3.5 kb of sequence including the nuclear ribosomal genes SSU, 5.8S, LSU, plus their internal transcribed spacer (ITS) 1 and 2 regions were determined for 26 individuals, including representatives of two genera for which molecular data were previously unavailable, Ornithocercus F. Stein and Histioneis F. Stein. In addition, a clone library targeting the dinophysiacean ITS2 and LSU sequences was constructed from bulk environmental DNA from three sites. Three phylogenetic trees were inferred from the data, one using data from this study for cells identified to genus or species (3.5 kb, 28 taxa); another containing dinoflagellate SSU submissions from GenBank and the 12 new dinophysiacean sequences (1.9 kb, 56 taxa) from this study; and the third tree combing data from identified taxa, dinophysiacean GenBank submissions, and the clone libraries from this study (2.1 kb, 136 taxa). All trees were congruent and indicated a distinct division between the genera Phalacroma F. Stein and Dinophysis Ehrenb. The cyanobionts containing genera Histioneis and Ornithocercus were also monophyletic. This was the largest molecular phylogeny of dinophysoid taxa performed to date and was consistent with the view that the genus Phalacroma may not be synonymous with Dinophysis. [source]


    JOURNAL OF PHYCOLOGY, Issue 2 2009

    On the basis of LM, we isolated strains of two species of fusiform green flagellates that could be assigned to former Chlorogonium (Cg.) Ehrenb. One species, "Cg."heimii Bourr., lacked a pyrenoid in its vegetative cells and required organic compounds for growth. The other was similar to Cg. elongatum (P. A. Dang.) Francé and "Cg."acus Nayal, but with slightly smaller vegetative cells. Their molecular phylogeny was also studied based on combined 18S rRNA, RUBISCO LSU (rbcL), and P700 chl a -apoprotein A2 (psaB) gene sequences. Both species were separated from Chlorogonium emend., Gungnir Nakada and Rusalka Nakada, which were formerly assigned to Chlorogonium. They were accordingly assigned to new genera, Tabris Nakada gen. nov. and Hamakko (Hk.) Nakada gen. nov. as T. heimii (Bourr.) Nakada comb. nov. and Hk. caudatus Nakada sp. nov., respectively. Tabris is differentiated from other genera of fusiform green flagellates by its vegetative cells, which only have two apical contractile vacuoles and lack a pyrenoid in the chloroplast. Hamakko, on the other hand, is distinguishable by the fact that its pyrenoids in vegetative cells are penetrated by flattened thylakoid lamellae. [source]


    Emily A. Buchholtz
    Abstract The vertebral column of the Atlantic white-sided dolphin, Lagenorhynchus acutus, reflects the radical reorganization of the cetacean column for locomotion in water. Both posterior thoracic and anterior caudal vertebrae have been "lumbarized," and discontinuities occur within the caudal series at the synclinal point and fluke base. Morphology changes subtly as body size increases. Neural process height increases more rapidly, and centrum length more variably, than other vertebral parameters. As a result, large animals have disproportionately tall neural processes, short necks, long mid-body regions, and short flukes. Vertebral columns of large animals also show greater complexity (range, irregularity, and polarization) of centrum length than do those of smaller animals. Comparisons among dolphins reveal that complexity trends with respect to differentiation of parts run counter to the trend with respect to number of parts, a relationship predicted by Williston in 1914. [source]


    PALAEONTOLOGY, Issue 4 2006
    Abstract:, A large number of fenestrate bryozoan species were named in ,A Synopsis of the Characters of the Carboniferous Limestone Fossils of Ireland' by Frederick M,Coy (1844). At the same time, M,Coy named the bryozoan genera Ichthyorachis, Ptylopora and Polypora, each of which by monotypy or by subsequent designation was based on new species within that work. Subsequently, d' Orbigny (1849) named Fenestrellina with the type species Fenestella crassa M,Coy, 1844 as type species; Miller (1961) named Parafenestella with the type species Fenestella formosa M,Coy, 1844 as type species; and Wyse Jackson (1988) named Baculopora with the type species Vincularia megastoma M,Coy, 1844. We re-describe here in more detail than previously the fenestrate type species originally published in M,Coy (1844), provide diagnoses of the genera, and compare the nineteenth century genera with more recently named genera that have been discriminated specifically from them. [source]


    JOURNAL OF PHYCOLOGY, Issue 4 2009
    Jana Korelusová
    The study and revision of the unicellular cyanobacterial genus Synechocystis was based on the type species S. aquatilis Sauv. and strain PCC 6803, a reference strain for this species. Uniformity in rRNA gene sequence, morphology, and ultrastructure was observed in all available Synechocystis strains, with the exception of the strain PCC 6308, which has been considered by some to be a model strain for Synechocystis. This strain differs substantially from the typical Synechocystis cluster according to both molecular (<90% of similarity, differences in 16S,23S rRNA internal transcribed spacer [ITS] secondary structure) and phenotypic criteria (different ultrastructure of cells). This strain is herein classified into the new genus Geminocystis gen. nov., as a sister taxon to the genus Cyanobacterium. Geminocystis differs from Cyanobacterium by genetic position (<94.4% of similarity) and more importantly by its different type of cell division. Because strain PCC 6308 was designated as a reference strain of the Synechocystis cluster 1 in Bergey's Manual, the members of this genetic cluster have to be revised and reclassified into Geminocystis gen. nov. Only the members of the Synechocystis cluster 2 allied with PCC 6803 correspond both genetically and phenotypically to the type species of the genus Synechocystis (S. aquatilis). [source]


    JOURNAL OF PHYCOLOGY, Issue 4 2007
    A new genus of Pfiesteria -like heterotrophic dinoflagellate, Luciella gen. nov., and two new species, Luciella masanensis sp. nov. and Luciella atlantis sp. nov., are described. These species commonly occur with other small (<20 ,m) heterotrophic and mixotrophic dinoflagellates in estuaries from Florida to Maryland and the southern coast of Korea, suggesting a possible global distribution. An SEM analysis indicates that members of the genus Luciella have the enhanced Kofoidian plate formula of Po, cp, X, 4,, 2a, 6,, 6c, PC, 5+s, 5,, 0p, and 2,,. The two four-sided anterior intercalary plates are diamond shaped. The genus Luciella differs from the other genera in the Pfiesteriaceae by a least one plate in the plate tabulation and in the configuration of the two anterior intercalary plates. An SSU rDNA phylogenetic analysis confirmed the genus as monophyletic and distinct from the other genera in the Pfiesteriaceae. The morphology of Luciella masanensis closely resembles Pfiesteria piscicida Steid. et J. M. Burkh. and other Pfiesteria -like dinoflagellates in size and shape, making it easily misidentified using LM. Luciella atlantis, in contrast, has a more distinctive morphology. It can be distinguished from L. masanensis and other Pfiesteria -like organisms by a larger cell size, a more conical-shaped epitheca and hypotheca, larger rhombic-shaped intercalary plates, and an asymmetrical hypotheca. The genus Luciella is assigned to the order Peridiniales and the family Pfiesteriaceae based on plate tabulation, plate pattern, general morphology, and phylogenetic analysis. [source]


    JOURNAL OF PHYCOLOGY, Issue 6 2000
    Stephen S. Bates
    First page of article [source]


    PALAEONTOLOGY, Issue 2 2009
    Abstract:, Based on new, bed-rock controlled material from Oman and Utah, USA, the Early Triassic genus Guodunites, which was recently erected on the basis of scarce specimens from northwestern Guangxi, South China, is now shown to be a representative of Proptychitidae. This solves the question of the previously unknown phylogenetic affinity of this genus. The genus is restricted to the late middle Smithian, and to date, its biogeographical distribution comprises Oman, South China and Utah, thus indicating an essentially low palaeolatitudinal distribution during the Early Triassic. Its palaeobiogeographical distribution further strengthens the existence of significant equatorial faunal exchanges between both sides of the Panthalassa at that time. It also suggests that, in addition to the potential stepping stones represented by Panthalassic terranes, vigorous equatorial oceanic currents must have contributed largely to the dispersal of ammonoids during such time intervals. [source]


    PALAEONTOLOGY, Issue 5 2008
    Abstract:, A new spinicaudatan genus and species, Ethmosestheria mahajangaensis gen. et sp. nov., is described from the Anembalemba Member (Upper Cretaceous, Maastrichtian) of the Maevarano Formation, Mahajanga Basin, Madagascar. This is the first spinicaudatan reported from the post-Triassic Mesozoic of Madagascar. The new species is assigned to the family Antronestheriidae based on the cavernous or sievelike ornamentation on the carapace. Of well-documented Mesozoic spinicaudatan genera, Ethmosestheria mahajangaensis is most closely related to Antronestheria Chen and Hudson from the Great Estuarine Group (Jurassic) of Scotland. However, relatively poor documentation of the ornamentation of most Gondwanan Mesozoic spinicaudatan species precludes detailed comparison among taxa. Ethmosestheria mahajangaensis exhibits ontogenetic trends in carapace growth: a change in carapace outline from subcircular/subelliptical to elliptical, and from very wide juvenile growth bands to narrow adult growth bands. Ornamentation style, however, does not vary with ontogeny. Ethmosestheria mahajangaensis individuals lived in temporary pools in a broad channel-belt system within a semiarid environment; preserved desiccation structures on carapaces indicate seasonal drying out of pools within the river system. Specimens of Ethmosestheria mahajangaensis are preserved with exquisite detail in debris flow deposits; these are the first spinicaudatans reported from debris flow deposits. These deposits also contain a varied vertebrate fauna, including dinosaurs, crocodyliforms, turtles, and frogs. Rapid entombment of the spinicaudatan carapaces likely promoted early fossil diagenesis leading to highly detailed preservation. [source]


    PALAEONTOLOGY, Issue 4 2007
    Abstract:, Soft-tissue preservation of the hind gut, or anal sac, in the tegmen of Tubulusocrinus (gen. nov.) doliolus (Wright) from the Mississippian (Visean, Asbian) Pittenweem Formation at St Andrews, Scotland, is the first of its kind known in crinoids; it sheds important new light on the nature of the cladid tegmen. Many cladid crinoids had a calcite-plated anal sac that may have functioned like a chimney to prevent fouling of the ambulacra. The tubular, uncalcified anal sac of Tubulusocrinus may have functioned like a hose by pointing down current between the arms to avoid fouling of the ambulacra. Its smaller size may also have required less energy to produce than a heavy-plated sac. The hind gut is apparently preserved by haematite replacement, which was probably altered from original authigenic pyrite that formed soon after catastrophic burial. [source]


    PALAEONTOLOGY, Issue 4 2006
    Abstract:, A portion of pterosaur skull from the Romualdo Member of the Santana Formation (?Albian,?Turonian, Cretaceous) of north-east Brazil provides new data on the morphology and ontogeny of azhdarchoid pterosaur cranial crests. The specimen consists of parts of the cranial bones posterodorsal to the nasoantorbital fenestra, including partial nasals, lacrimals, frontals and possibly the parietals. A posterodorsally directed premaxillary crest with a concave posterior border is located dorsal to the posterior border of the nasoantorbital fenestra. A well-defined suture indicates overlapping, posterodorsally directed growth of the premaxilla over the skull roof, suggesting that the generation of the premaxillary crest is a late ontogenetic feature and thus probably related to sexual display. The systematics of Tupuxuara and its relationship to other azhdarchoids is reviewed and a cladistic analysis of the group is presented. Tupuxuara is found to be the sister-taxon to Azhdarchidae. Tupuxuara longicristatus Kellner and Campos, 1988 is argued to be the only valid named species in this genus and Thalassodromeus Kellner and Campos, 2002 is considered a junior subjective synonym of this taxon. As originally conceived, Tapejaridae is paraphyletic: a new, more restrictive version of Tapejaridae (including Tapejara and Sinopterus dongi) might exist, but its monophyly is weakly supported. Furthermore, Tapejara was found to be paraphyletic in all trees. [source]

    Molecular phylogeny and biogeography of Honey-buzzards (genera Pernis and Henicopernis)

    A. Gamauf
    Abstract A partial sequence of the cytb gene (382 bp) was amplified and sequenced from 35 individuals (mainly museum specimens) of the genus Pernis representing all valid taxa (10) and two taxa (P. p. gurneyi, P. p. japonicus) with questionable validity as well as representatives of the Old World Perninae, namely Henicopernis and Aviceda, to assess their relationships to the genus Pernis. Furthermore, Gypaetus barbatus, Neophron percnopterus, and Buteo buteo were included as outgroup taxa. In the trees derived from the sequence data, Aviceda represents the sister group of the genus Pernis. The genus Henicopernis and the Old World vultures Gypaetus andNeophron appear rather distantly related to Pernis. Within the genus Pernis, two of the described species (Pernis apivorus, Pernis ptilorhyncus) form monophyletic groups, whereas the relationships of the two clades representing three subspecies of Pernis celebensis are still uncertain. Although this study is based on comparatively short DNA-sections, the trees deduced from these sequences can be considered as a first approach for inferring the phylogenetic relationships of the genus Pernis and related genera and for addressing questions concerning the evolutionary history, biogeography, and systematics of this group. Zusammenfassung Eine Teilsequenz des Cytochrom b Gens (382 bp) wurde von 35 Individuen (hauptsächlich Museumsmaterial) der Gattung Pernis amplifiziert und sequenziert. Inkludiert wurden alle validen Taxa (10) und zwei weitere (P.p. gurneyi, P. p. japonicus) mit zweifelhaftem taxonomischen Status. Weiters wurden die übrigen Vertreter der altweltlichen Perninae (Henicopernis, Aviceda) untersucht, um deren Verwandtschaft zum Genus Pernis festzustellen. Als Außengruppen-Taxa wurden Bartgeier Gypaetus barbatus, Schmutzgeier Neophron percnopterus und Mäusebussard Buteo buteo verwendet. In den aus den Sequenzen errechneten Bäumen stellt Aviceda die Schwestergruppe der Gattung Pernis dar. Die Gattungen, Henicopernis und die Altweltgeier Gypaetus und Neophron erscheinen mit der Gattung Pernis nur entfernt verwandt. Innerhalb der Gattung Pernis formen zwei der beschriebenen Arten (P. apivorus, P. ptilorhyncus) eine monophyletische Gruppe, die Verwandtschaftsverhältnisse der beiden anderen Clades, welche die drei Unterarten von P. celebensis repräsentieren, können jedoch auf der Basis dieser Sequenz nicht eindeutig geklärt werden. Obwohl diese Analyse auf relativ kurzen DNA-Abschnitten basiert, können die aus den Sequenzen abgeleiteten Stammbäume als erster Versuch angesehen werden, die Phylogenie der Wespenbussard-Gattung Pernis und verwandter Genera mittels molekularer Methoden und unter Berücksichtigung evolutionsbiologischer, biogeographischer und systematischer Aspekte darzustellen. [source]

    Accounting and Mediating: Modes, Genera, Voice-leading and Form in Milhaud

    MUSIC ANALYSIS, Issue 2 2000
    Michael Russ
    First page of article [source]

    A Molecular Phylogenetic Investigation of Opisthonecta and Related Genera (Ciliophora, Peritrichia, Sessilida)

    ABSTRACT. The gene encoding 18S small subunit ribosomal RNA (ssu rRNA) was sequenced in the sessiline peritrichs Opisthonecta minima and Opisthonecta matiensis, whose free-swimming, paedomorphic trophonts resemble telotrochs. Using these new sequences, phylogenetic trees were constructed with four different methods to test a previously published association between Opisthonecta henneguyi and members of the families Vorticellidae and Astylozoidae. All trees had similar topologies, with O. minima, O. henneguyi, Vorticella microstoma, and Astylozoon enriquesi forming a well-supported, certainly monophyletic clade. On the basis of genetic evidence, genera of the families Opisthonectidae and Astylozoidae are assigned to the family Vorticellidae, which already includes some species with free-swimming morphotypes. The ssu rRNA sequence of O. matiensis places it in the family Epistylididae; its taxonomic revision will be left to another group of authors. A close association of Ophrydium versatile with members of the family Vorticellidae was confirmed, casting doubt on the validity of the family Ophrydiidae. Epistylis galea, Campanella umbellaria, and Opercularia microdiscum are confirmed as comprising an extremely distinct, monophyletic, but morphologically heterogeneous clade that is basal to other clades of sessiline peritrichs. [source]

    Seed plants of Fiji: an ecological analysis

    An annotated list of indigenous Fijian seed plant genera is presented and comprises 484 genera and 1315 species in 137 families. The relative diversity of the largest families and genera in Fiji is indicated and compared with floras in New Caledonia and the Upper Watut Valley, Papua New Guinea. Differences and similarities appear to be due to biogeographical/phylogenetic factors rather than ecological differences or means of dispersal. Generic diversity for the seed plants as a whole is greatest between 0,100 m and decreases monotonically with altitude. However, in the largest family, Orchidaceae, maximum diversity occurs between 200,400 m. Fifty percent of the families are recorded from shore habitat. Twenty-seven percent of the families and 80 species occur in or around mangrove, where the most diverse families are Orchidaceae, Rubiaceae, and the legumes. Some of the mangrove-associate species are pantropical or Indo-Pacific but most are locally or regionally endemic. Fifty-six percent of the Fijian families are recorded on limestone. Twenty-nine species are restricted to limestone and 12 species usually occur on limestone. The importance of calcium in reducing the effects of salinity is emphasized and 39 species are recorded from both mangrove and limestone. A plagiotropic habit occurs in 38 species which occur on limestone or around beaches, and 20 of these are Pacific endemics. Genera restricted to higher altitudes include many present elsewhere in Melanesia but absent from Australia despite suitable habitat there, again indicating the importance of biogeographical and historical factors. Altitudinal anomalies in Fiji taxa are cited and include 7 anomalously high records from northern Viti Levu, a site of major uplift, and 22 anomalously low altitudinal records in the Lau Group, a site of subsidence. It is suggested that the Fijian flora has not been derived from immigrants from Asia, but has evolved more or less in situ. Taxa would have survived as metapopulations on the individually ephemeral volcanic islands always found at oceanic subduction zones and hot spots, and the atolls which characterize areas of subsidence. The complex geology of Fiji is determined by its position between two subduction zones of opposite polarity, the Vanuatu and Tonga Trenches, in what is currently a region of transform faulting. The large islands comprise fragments of island arcs that have amalgamated and welded together. There has been considerable uplift as well as subsidence in the islands and it is suggested that both these processes have had drastic effects on the altitudinal range of the taxa. Limestone and mangrove floras could have provided a widespread, diverse ancestral species pool from which freshwater swamp forest, lowland rainforest, dry forest, secondary forest, thickets, and montane forest have been derived during phases of uplift. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 89, 407,431. [source]

    Taxonomic Study of Korean Cantharidae (Coleoptera) V. A Newly Recorded Genus and Species, Pseudoabsidia ussurica Wittmer, from Korea

    Tau KANG
    ABSTRACT We examined newly recorded species, Pseudoabsidia ussurica Wittmer, from Korea. The species was redescribed with their color variation. Also, the photos of adult habitus and aedeagus are provided. [source]

    A New AcanthocyclopsKiefer, 1927 (Copepoda: Cyclopoida) from Central Mexico with Comments on the Distributionof the Genus in Middle America

    Nancy Mercado
    Abstract A new species of AcanthocyclopsKiefer is described from central Mexico. It differs from its congeners by a combination of characters including mainly: 11,13 antennular segments, a spine formula of 3444 and modified setae on legs 2,4. The presence of a compound distal antennular segment is aberrant within the Cyclopoida. The new species seems to be related to Nearctic forms of the vernalis ,robustus clade. Ancestors of this lineage probably reached central Mexico as a result of glaciation events and the new species is a remain of stranded postglacial populations; some of these forms were succesful in colonizing tropical lands. A key for the identification of the species of Acanthocyclops recorded in Mexico is included. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Utricularia (Lentibulariaceae) , a New Host Plant Genus of Powdery Mildew (Sphaerotheca sp.)

    Symptoms of powdery mildew infections were recorded on a group of 15 Utricularia species cultivated in a glasshouse. A white superficial mycelium formed rings around the peduncles and also occurred on both sides of the leaves of several species. The microscopic examination proved that the fungus belonged to the powdery mildews , Erysiphales, only the anamorph was observed. Its morphological characters are typical for powdery mildews from the tribe Cystotheceae. Conidia were able to cause infections on cotyledons of susceptible Cucumis sativus cv. Stela F1. Based on all observations, it is very probable that this fungus belongs to the genus Sphaerotheca. This is the first report of a powdery mildew on Utricularia spp. and the family Lentibulariaceae. Utricularia(Lentibulariaceae) , eine neue Wirtspflanzengattung des Echten Mehltaus (Sphaerothecasp.) Symptome von Infektionen mit dem Echten Mehltau wurden bei einer Gruppe von 15 in einem Gewächshaus gehaltenen Utricularia -Arten festgestellt. Ein weißes oberflächliches Myzel bildete Ringe um die Blütenstandsstiele und trat bei verschiedenen Arten auch auf beiden Seiten der Blätter auf. Mikroskopische Untersuchungen ergaben, daß es sich um einen Echten Mehltaupilz (Erysiphales) handelte; ausschließlich die Anamorph wurde beobachtet. Die morphologischen Merkmale sind typisch für Echte Mehltaupilze vom Stamm Cystotheceae. Die Konidien konnten auch Infektionen auf den Keimblättern anfälliger Pflanzen von Cucumis sativus cv. Stela F1 auslösen. Auf der Grundlage aller Beobachtungen erscheint es als sehr wahrscheinlich, daß dieser Pilz der Gattung Sphaerotheca angehört. Dies ist der erste Bericht über Echten Mehltau an Utricularia spp. und der Familie Lentibulariaceae. [source]

    Tobacco blue mould disease caused by Peronospora hyoscyami f. sp. tabacina

    SUMMARY Blue mould [Peronospora hyoscyami f. sp. tabacina (Adam) Skalicky 1964] is one of the most important foliar diseases of tobacco that causes significant losses in the Americas, south-eastern Europe and the Middle East. This review summarizes the current knowledge of the mechanisms employed by this oomycete pathogen to colonize its host, with emphasis on molecular aspects of pathogenicity. In addition, key biochemical and molecular mechanisms involved in tobacco resistance to blue mould are discussed. Taxonomy: Kingdom: Chromista (Straminipila); Phylum: Heterokontophyta; Class: Oomycete; Order: Peronosporales; Family: Peronosporaceae; Genus: Peronospora; Species: Peronospora hyoscyami f. sp. tabacina. Disease symptoms: The pathogen typically causes localized lesions on tobacco leaves that appear as single, or groups of, yellow spots that often coalesce to form light-brown necrotic areas. Some of the leaves exhibit grey to bluish downy mould on their lower surfaces. Diseased leaves can become twisted, such that the lower surfaces turn upwards. In such cases, the bluish colour of the diseased plants becomes quite conspicuous, especially under moist conditions when sporulation is abundant. Hence the name of the disease: tobacco blue mould. Infection process: The pathogen develops haustoria within plant cells that are thought to establish the transfer of nutrients from the host cell, and may also act in the delivery of effector proteins during infection. Resistance: Several defence responses have been reported to occur in the Nicotiana tabacum,P. hyoscyami f. sp. tabacina interaction. These include the induction of pathogenesis-related genes, and a correlated increase in the activities of typical pathogenesis-related proteins, such as peroxidases, chitinases, ,-1,3-glucanases and lipoxygenases. Systemic acquired resistance is one of the best characterized tobacco defence responses activated on pathogen infection. [source]

    A Review Of Two De Koninck Retzioid Brachiopod Species, And Description Of A New Genus From The Carboniferous Of Europe

    PALAEONTOLOGY, Issue 5 2000
    Fernando Alvarez
    A new neoretziid brachiopod genus, Coveenia, from the Lower Carboniferous of western Europe is erected; the type species is Coveenia ulothrix (de Koninck, 1843), and C. buchiana (de Koninck, 1843, sensu 1887) and C. tilsleia sp. nov. are included, diagnosed and described. Neotypes are selected and illustrated for C. ulothrixC. buchiana. [source]

    Morphogenesis in the Marine Spirotrichous Ciliate Apokeronopsis crassa (Claparède & Lachmann, 1858) n. comb. (Ciliophora: Stichotrichia), with the Establishment of a New Genus, Apokeronopsis n. g., and Redefinition of the Genus Thigmokeronopsis

    ABSTRACT. Morphogenetic events during the division of the marine spirotrichous ciliate, Apokeronopsis crassa (Claparède & Lachmann 1858) n. comb. were investigated. Compared with members of the well-known genera Thigmokeronopsis, Uroleptopsis, and Pseudokeronopsis, A. crassa has one row of buccal cirri, high number of transverse cirri, clearly separated midventral rows, lacks thigmotactic cirri and a gap in adoral zone, its undulating membranes (UMs) anlage forms one cirrus and marginal rows and dorsal kineties form apokinetally during division. All these characteristics indicate that this organism represents a new taxon at the generic level, and hence a new genus is suggested, Apokeronopsis n. g. It is defined as thus: Pseudokeronopsidae with Pseudokeronopsis -like bicorona of frontal cirri and one marginal row on each side; one row of two or more buccal cirri in ordinary position; two midventral rows distinctly separated, hence of cirri that are not in a typical zig-zag pattern; high number of transverse cirri, caudal cirri absent, and frontoterminal cirri present; thigmotactic cirri absent, many macronuclear nodules fuse into many masses as well as marginal and dorsal kineties form apokinetally during morphogenesis. At the same time, the genus ThigmokeronopsisWicklow, 1981 is redefined, and one new combination, Apokeronopsis antarctica (Petz, 1995) n. comb. is proposed. The morphogenetic events of A. crassa are characterized as follows: (1) In the proter, the adoral zone of membranelles and UMs are completely renewed by the oral primordium. The UM anlage is formed apokinetally on the dorsal wall of the buccal cavity and is hence clearly separated from the frontoventral-transverse (FVT) cirral anlagen in the proter. (2) Frontoventral-transverse cirral anlagen are generated de novo in the outermost region of the cortex to the right of the old UMs. (3) A row of buccal cirri arises from FVT cirral streak I. (4) The marginal rows and dorsal kineties originate de novo in both dividers; no caudal cirri are formed. (5) The last FVT-streak contributes two frontoterminal cirri. (6) The many macronuclear nodules fuse into many masses (about 50 segments) during division, unlike a singular or branched mass as described in other urostylids. [source]

    Informative Characteristics of 12 Divergent Domains in Complete Large Subunit rDNA Sequences from the Harmful Dinoflagellate Genus, Alexandrium (Dinophyceae)

    ABSTRACT. The genus Alexandrium includes organisms of interest, both for the study of dinoflagellate evolution and for their impacts as toxic algae affecting human health and fisheries. Only partial large subunit (LSU) rDNA sequences of Alexandrium and other dinoflagellates are available, although they contain much genetic information. Here, we report complete LSU rDNA sequences from 11 strains of Alexandrium, including Alexandrium affine, Alexandrium catenella, Alexandrium fundyense, Alexandrium minutum, and Alexandrium tamarense, and discuss their segmented domains and structure. Putative LSU rRNA coding regions were recorded to be around 3,400bp long. Their GC content (about 43.7%) is among the lowest when compared with other organisms. Furthermore, no AT-rich regions were found in Alexandrium LSU rDNA, although a low GC content was recorded within the LSU rDNA. No intron-like sequences were found. The secondary structure of the LSU rDNA and parsimony analyses showed that most variation in LSU rDNA is found in the divergent (D) domains with the D2 region being the most informative. This high D domain variability can allow members of the diverse Alexandrium genus to be categorized at the species level. In addition, phylogenetic analysis of the alveolate group using the complete LSU sequences strongly supported previous findings that the dinoflagellates and apicomplexans form a clade. [source]

    New Genus of the Subfamily Geotrupinae (Coleoptera: Scarabaeoidea: Geotrupindae) from the Jehol Biota

    Georgiy V. NIKOLAJEV
    Abstract: Parageotrupes incanus gen. et sp. nov. (Scarabaeoidea: Geotrupidae: Geotrupinae) is described and illustrated from the Yixian Formation of western Liaoning province, China. [source]

    New Genus and Species of Fossil Dragonflies (Insecta: Odonata) from the Yixian Formation of Northeastern China

    ZHANG Binglan
    Abstract, Two well-preserved fossil dragonflies from the Late Mesozoic Yixian Formation, Liaoning Province, China are described and assigned to a new genus, Sopholibellula gen. nov. in Araripelibellulidae Bechly, 1996, closely related to the type genus Araripelibellula. This new genus differs from Araripelibellula in the following characters: origins of RP and MA distinctly separated at arculus in both pairs of wings; anal loop wider and shorter, with Y-shaped veins inside; MA and IR2 not zigzag; several small intercalary veins present in the postdiscoidal area of hindwing; cells smaller and much more dense, especially in the apex and hind margin; bigger in size. Structures, including head, abdomen and parts of legs, were first described in details of this family. [source]

    A New Genus of Psittacosauridae (Dinosauria: Ornithopoda) and the Origin and Early Evolution of Marginocephalian Dinosaurs

    YOU Hailu
    Abstract, An almost complete juvenile dinosaur skull with lower jaw was discovered from the Early Cretaceous Yixian Formation in Beipiao, Liaoning Province, China. Here, the specimen is described and a cladistic analysis is performed in order to find its phylogenetic relationships. The result shows that this specimen represents a new genus of Psittacosauridae, Hongshanosaurus houi, gen. et sp. nov., and confirms the monophyletic status for Ceratopsia and Marginocephalia. However, Heterodontosaurus is found to be the sister taxon to Marginocephalia, rather than a basal Ornithopoda. [source]


    Michael F. Fay
    Summary. Plants that parasitise other plants have been among the most difficult plant groups to fit into classification systems due to their modified biology and their often highly reduced morphology. They are now considered to be found in about 16 families of flowering plants. Here we summarise current ideas about their relationships and provide information about their characteristics and utilisation. A major consequence of the revised classification of Orobanchaceae and related families has been the break-up of the traditional Scrophulariaceae, and here we summarise the new classification, focusing on genera of horticultural interest. [source]

    Biodiversity and distribution of epibiontic communities on Caridina ensifera (Crustacea, Decapoda, Atyidae) from Lake Poso: comparison with another ancient lake system of Sulawesi (Indonesia)

    ACTA ZOOLOGICA, Issue 2 2010
    Gregorio Fernandez-Leborans
    Abstract Fernandez-Leborans, G. and von Rintelen, K. 2010. Biodiversity and distribution of epibiontic communities on Caridina ensifera (Crustacea, Decapoda, Atyidae) from Lake Poso: comparison with another ancient lake system of Sulawesi (Indonesia). , Acta Zoologica (Stockholm) 91: 163,175 The epibiont communities of the shrimp Caridina ensifera, endemic to Lake Poso (Sulawesi, Indonesia), were analysed. Most of the epibiont species were ciliated protozoa belonging to three suctorian genera (Acineta, Podophrya and Spelaeophrya), three peritrich genera (Zoothamnium, Vorticella and Cothurnia), and a haptorid genus (Amphileptus). There was also a rotifer epibiont of the genus Embata. Epibionts were identified to species level. There were 14 to 1114 epibionts per shrimp. The distribution of the epibiont species on the surface of the basibiont was recorded, calculating the number on the different colonized individuals of C. ensifera. The most abundant species, Zoothamnium intermedium and Acineta sulawesiensis, were also the most widely distributed. There was a significant difference between the spatial distributions of the different epibiont species. The analysis of the number of the epibiont species throughout the anteroposterior axis of the shrimp showed a gradient from the anterior to the posterior end of the body. Data from Lake Poso were compared with those of the Malili lake system (Sulawesi), obtained from its endemic shrimp, Caridina lanceolata. Lake Poso had the highest mean diversity, while Lake Mahalona showed the highest maximum diversity. All lakes were correlated with respect to the mean number of epibionts on the anatomical units of the shrimp, which showed a similar general distribution. The distributions of the different epibiont species were compared between the lakes. The possible adaptations of the epibionts as well as the colonization patterns were discussed. From the statistical results and the analysis of the distributions, we propose that in these communities epibiont species have a pattern of colonization in which they follow a behaviour as a whole; each species has a differential distribution, with the species occupying the available substratum with the particular requirements of each functional group, but there is a trend towards maintaining an equilibrium among species and groups, compensating for diversity and number of individuals. In all lakes there was an epibiont distribution model comprising the maintenance of an anteroposterior axis gradient, which was supported by the fluctuation in diversity and number of individuals of the different functional groups of epibiont species. The functional role of the different groups of species seems to tend towards sustainability with little global variation among the lakes. [source]

    BIODIVERSITY RESEARCH: Genetic diversity in two introduced biofouling amphipods (Ampithoe valida & Jassa marmorata) along the Pacific North American coast: investigation into molecular identification and cryptic diversity

    Erik M. Pilgrim
    Abstract Aim, We investigated patterns of genetic diversity among invasive populations of Ampithoe valida and Jassa marmorata from the Pacific North American coast to assess the accuracy of morphological identification and determine whether or not cryptic diversity and multiple introductions contribute to the contemporary distribution of these species in the region. Location, Native range: Atlantic North American coast; Invaded range: Pacific North American coast. Methods, We assessed indices of genetic diversity based on DNA sequence data from the mitochondrial cytochrome c oxidase subunit I (COI) gene, determined the distribution of COI haplotypes among populations in both the invasive and putative native ranges of A. valida and J. marmorata and reconstructed phylogenetic relationships among COI haplotypes using both maximum parsimony and Bayesian approaches. Results, Phylogenetic inference indicates that inaccurate species-level identifications by morphological criteria are common among Jassa specimens. In addition, our data reveal the presence of three well supported but previously unrecognized clades of A. valida among specimens in the north-eastern Pacific. Different species of Jassa and different genetic lineages of Ampithoe exhibit striking disparity in geographic distribution across the region as well as substantial differences in genetic diversity indices. Main conclusions, Molecular genetic methods greatly improve the accuracy and resolution of identifications for invasive benthic marine amphipods at the species level and below. Our data suggest that multiple cryptic introductions of Ampithoe have occurred in the north-eastern Pacific and highlight uncertainty regarding the origin and invasion histories of both Jassa and Ampithoe species. Additional morphological and genetic analyses are necessary to clarify the taxonomy and native biogeography of both amphipod genera. [source]

    Global biogeographical data bases on marine fishes: caveat emptor

    D. Ross Robertson
    ABSTRACT A review of georeferenced collection-site records for Caribbean shore-fishes served by major online distributors of aggregated biodiversity data found large-scale errors in over a third of the species and genera, in nearly two-thirds of the families. To avoid compromising the value of their services to the global science community online providers must actively address the question of data quality. [source]

    Conifers as invasive aliens: a global survey and predictive framework

    David M. Richardson
    ABSTRACT We summarize information on naturalized and invasive conifers (class Pinopsida) worldwide (data from 40 countries, some with remote states/territories), and contrast these findings with patterns for other gymnosperms (classes Cycadopsida, Gnetopsida and Ginkgoopsida) and for woody angiosperms. Eighty conifer taxa (79 species and one hybrid; 13% of species) are known to be naturalized, and 36 species (6%) are ,invasive'. This categorization is based on objective and conservative criteria relating to consistency of reproduction, distance of spread from founders, and degree of reliance on propagules from the founder population for persistence in areas well outside the natural range of species. Twenty-eight of the known invasive conifers belong to one family (Pinaceae) and 21 of these are in one genus (Pinus). The Cupressaceae (including Taxodiaceae) has six known invasive species (4%) in four genera, but the other four conifer families have none. There are also no known invasive species in classes Cycadopsida, Gnetopsida or Ginkgoopsida. No angiosperm family comprising predominantly trees and shrubs has proportionally as many invasive species as the Pinaceae. Besides the marked taxonomic bias in favour of Pinaceae, and Pinus in particular, invasiveness in conifers is associated with a syndrome of life-history traits: small seed mass (< 50 mg), short juvenile period (< 10 year), and short intervals between large seed crops. Cryptomeria japonica, Larix decidua, Picea sitchensis, Pinus contorta, Pinus strobus, and Pseudotsuga menziesii exemplify this syndrome. Many rare and endangered conifer species exhibit opposite characters. These results are consistent with earlier predictions made using a discriminant function derived from attributes of invasive and noninvasive Pinus species. Informative exceptions are species with small seeds (< 4 mg, e.g. Chamaecyparis spp., Pinus banksiana, Tsuga spp. , mostly limited to wet/mineral substrates) or otherwise ,non-invasive' characters (e.g. large seeds, fleshy fruits, e.g. Araucaria araucana, Pinus pinea, Taxus baccata that are dependent on vertebrates for seed dispersal). Most conifers do not require coevolved mutualists for pollination and seed dispersal. Also, many species can persist in small populations but have the genetic and reproductive capacity to colonize and increase population size rapidly. The underlying mechanisms mediating conifer invasions are thus easier to discern than is the case for most angiosperms. Further information is needed to determine the extent to which propagule pressure (widespread dissemination, abundant plantings, long history of cultivation) can compensate for low ,inherent invasiveness'. [source]