720 resultados para AMPHIBIA: ANURA: BUFONIDAE
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Includes bibliographies and index.
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--VI. Insects, pt. II. Hymenoptera continued (Tubilifera and Aculeata), Coleoptera, Strepsiptera, Lepidotera, Diptera, Aphaniptera, Thysanoptera, Hemiptera, Anoplura. By David Sharp. 1901.--VII. Hemichordata, by S.F. Harmer. Ascidians and Amphioxus, by W.A. Herdman. Fishes (exclusive of th systematic account of Teleostei) by T.W. Bridge. Fishes (systematic account of Teleostei) by G.A. Bonlenger. 1904.--VIII. Amphibia and reptiles, by Hans Gadow. 1901.--IX. Birds, by A.H. Evans. 1900--X. Mammalia, by F.E. Beddard. 1902.
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Despite a considerable surge in herpetological research in Australia over the last couple of decades the Australian microhylid frogs (Cophixalus and Austrochaperina) remain relatively poorly known. Herein I present the results of extensive fieldwork and molecular, morphological and call analysis with the aim of resolving taxonomy, call variation and distributions, and increasing our understanding of breeding biology. Analysis of 943 base pairs of mitochondrial 16S rRNA and 12S rRNA provides a well supported phylogeny that is largely consistent with current taxonomy. Levels of divergence between species are substantial and significant phylogeographic structuring is evident in C. ornatus, C. neglectus and C. aenigma, sp. nov. The description of C. concinnus was based on a mixed collection of two species from Thornton Peak and a new species is described to resolve this. C. aenigma, sp. nov., is described from high-elevation (>750 m) rainforest across the Carbine, Thornton, Finnigan and Bakers Blue Mountain uplands, north-east Queensland. C. concinnus is redescribed as a highly distinct species restricted to rainforest and boulder fields at the summit of Thornton Peak (>1100 m). Despite protection in Daintree National Park in the Wet Tropics World Heritage Area, predictions of the impact of global warming suggest C. concinnus to be of very high conservation concern ( Critically Endangered, IUCN criteria). The mating call of two species ( C. mcdonaldi and C. exiguus) is described for the first time and high levels of call variation within C. ornatus, C. neglectus, C. hosmeri, C. aenigma and Austrochaperina fryi are presented. Such variation is often attributable to genetically divergent lineages, altitudinal variation and courtship; however, in some instances ( particularly within C. hosmeri) the source or function of highly distinct calls at a site remains obscure. Molecular, morphological and call analyses allow the clarification of species distributions, especially in the northern mountains of the Wet Tropics. Notes are presented on the breeding biology of C. aenigma, C. bombiens, C. concinnus, C. exiguus, C. infacetus, C. mcdonaldi, C. monticola, C. neglectus, C. ornatus and C. saxatilis, which are largely consistent with previous accounts: small terrestrial clutches usually attended by a male. Courtship behaviour in C. ornatus is described and the first records of multiple clutching in Australian microhylids are presented (for C. ornatus and C. infacetus).
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The presence of primary cilia in corneal endothelial cells of a range of species from six non-mammalian vertebrate classes (Agnatha, Elasmobranchii, Amphibia, Teleostei, Reptilia, and Aves) is examined by scanning and transmission electron microscopy. Our aim is to assess whether these non-motile cilia protruding into the anterior chamber of the eye are a consistent phylogenetic feature of the corneal endothelium and if a quantitative comparison of their morphology is able to shed any new light on their function. The length (0.42-3.80 mum) and width (0.12-0.44 mum) of the primary cilia varied but were closely allied with previous studies in mammals. However, interspecific differences such as the presence of a terminal swelling in the Teleostei and Amphibia suggest there are functional differences. Approximately one-third of the endothelial cells possess cilia but the extent of protrusion above the cell surface varies greatly, supporting a dynamic process of retraction and elongation. The absence of primary cilia in primitive vertebrates (Agnatha and Elasmobranchii) that possess other mechanisms to control corneal hydration suggests an osmoregulatory and/or chemosensory function. (C) 2003 Elsevier Ltd. All rights reserved.
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The effects of short-term fasting and prolonged fasting during aestivation on the morphology of the proximal small intestine and associated organs were investigated in the green-striped burrowing frog, Cyclorana alboguttata (Anura: Hylidae). Animals were fasted for 1 week while active or for 3-9 months during aestivation. Short-duration fasting (1 week) had little effect on the morphology of the small intestine, whilst prolonged fasting during aestivation induced marked enteropathy including reductions in intestinal mass, length and diameter, longitudinal fold height and tunica muscularis thickness. Enterocyte morphology was also affected markedly by prolonged fasting: enterocyte cross-sectional area and microvillous height were reduced during aestivation, intercellular spaces were visibly reduced and the prevalence of lymphocytes amongst enterocytes was increased. Mitochondria and nuclei were also affected by 9 months of aestivation with major disruptions to mitochondrial cristae and increased clumping of nuclear material and increased infolding of the nuclear envelope. The present study demonstrates that the intestine of an aestivating frog responds to prolonged food deprivation during aestivation by reducing in size, presumably to reduce the energy expenditure of the organ.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Past changes in plant and landscape diversity can be evaluated through pollen analysis, however, pollen based diversity indexes are potentially biased by differential pollen production and deposition. Studies examining the relationship between pollen and landscape diversity are therefore needed. The aim of this study is to evaluate how different pollen based indexes capture aspects of landscape diversity. Pollen counts were obtained from surface samples of 50 small to medium sized lakes in Brandenburg (Northeast Germany) and compiled into two sets, with one containing all pollen counts from terrestrial plants and the second restricted to wind-pollinated taxa. Both sets were adjusted for the pollen production/dispersal bias using the REVEALS model. A high resolution biotope map was used to extract the density of total biotopes and different biotopes per area as parameters describing landscape diversity. In addition tree species diversity was obtained from forest inventory data. The Shannon index and the number of taxa in a sample of 10 pollen grains are highly correlated and provide a useful measure of pollen type diversity which corresponds best to landscape diversity within one km of the lake and the proportion of non-forested area within seven km. Adjustments of the pollen production/dispersal bias only slightly improve the relationships between pollen diversity and landscape diversity for the restricted dataset as well as for the forest inventory data and corresponding pollen types. Using rarefaction analysis, we propose the following convention: pollen type diversity is represented by the number of types in a small sample (low count e.g. 10), pollen type richness is the number of types in a large sample (high count e.g. 500) and pollen sample evenness is characterized by the ratio of the two. Synthesis. Pollen type diversity is a robust index that captures vegetation structure and landscape diversity. It is ideally suited for between site comparisons as it does not require high pollen counts. In concert with pollen type richness and evenness, it helps evaluating the effect of climate change and human land use on vegetation structure on long timescales.
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Abundant material of turtles from the early Oligocene site of Boutersem-TGV (Boutersem, Belgium), is presented here. No information on the turtles found there was so far available. All the turtle specimens presented here are attributable to a single freshwater taxon that is identified as a member of Geoemydidae, Cuvierichelys. It is the first representative of the ‘Palaeochelys s. l.–Mauremys’ group recognized in the Belgian Paleogene record. This material, which allows to know all the elements of both the carapace and the plastron of the taxon, cannot be attributed to the only species of the genus Cuvierichelys so far identified in the Oligocene, the Spanish form Cuvierichelys iberica. The taxon from Boutersem is recognized as Cuvierichelys parisiensis. Thus, both the paleobiogeographic and the biostratigraphic distributions of Cuvierichelys parisiensis are extended, its presence being confirmed for the first time outside the French Eocene record. The validity of some European forms is refuted, and several characters previously proposed as different between Cuvierichelys iberica and Cuvierichelys parisiensis are recognized as subjected to intraspecific variability.
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The Early Miocene Napak XV locality (ca 20.5 Ma), Uganda, has yielded an interesting assemblage of fossils, including the very well represented amphicyonid Hecubides euryodon. The remarkable find of a nearly complete mandible, unfortunately with poorly preserved dentition, together with new dental remains allow us to obtain a better idea about the morphology and variability of this species. Additionally, we describe a newly discovered mandible of Hecubides euryodon from the Grillental-VI locality (Sperrgebiet, Namibia), which is the most complete and diagnostic Amphicyonidae material found in this area. Comparisons with Cynelos lemanensis from Saint Gérand le Pouy (France), the type locality, and with an updated sample of the species of amphicyonids described in Africa leads us to validate the genus Hecubides. Hecubides would be phylogenetically related to the medium and large size species of Amphicyonidae from Africa, most of them now grouped into the genera Afrocyon and Myacyon, both endemic to this continent.
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Little is known about long-term ecological responses in lakes following red mud pollution. Among red mud contaminants, arsenic (As) is of considerable concern. Determination of the species of As accumulated in aquatic organisms provides important information about the biogeochemical cycling of the element and transfer through the aquatic food-web to higher organisms. We used coupled ion chromatography and inductively coupled plasma mass spectrometry (ICP-MS) to assess As speciation in tissues of five macrophyte taxa in Kinghorn Loch, UK, 30 years following the diversion of red mud pollution from the lake. Toxic inorganic As was the dominant species in the studied macrophytes, with As species concentrations varying with macrophyte taxon and tissue type. The highest As content measured in roots of Persicaria amphibia (L.) Gray (87.2 mg kg-1) greatly exceeded the 3 - 10 mg kg-1 range suggested as a potential phytotoxic level. Accumulation of toxic As species by plants suggested toxicological risk to higher organisms known to utilise macrophytes as a food source.
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[EN] The presence of the green and Kemp's ridley turtles is rare at Atlantic and Mediterranean Spanish waters, but the records have increased during the last decades. We reported a new set of records and reviewed all the historical observations of these species. The analysis of a mitochondrial DNA fragment of the newest records provided insights about the origin of the individuals. The Kemp's ridley turtles arrived from the western Atlantic nesting beaches, although the discovering of a new haplotype suggested the existence of an unknown or low sampled nesting area of origin.