915 resultados para FROG DIVERSITY
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The Atlantic Forest is considered one of the world's biological diversity hotspots but is nevertheless increasingly threatened with the rapid destruction and fragmentation of its natural areas. In the state of Santa Catarina, southern Brazil, remnants of the mixed ombrophilous forest and seasonal deciduous forest exist as islands within large areas of agriculture, pastures and human settlements. Here we present information on species richness and habitat use by anurans in the Floresta Nacional de Chapecó, located in the western portion of the state of Santa Catarina. Anurans were surveyed by active search of potential reproductive sites from December 1998 to December 2001. A total of 29 species were recorded, most of which have a known distribution restricted to southern Brazil and adjacent countries (Argentina, Paraguay, and Uruguay) and use open areas for reproduction. The species composition was most similar to other areas of mixed ombrophilous forest and seasonal deciduous forest from the extreme south of Brazil. The information in this study may support the implementation of conservation and management strategies in the area.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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A new species of the tree toad genus Dendrophryniscus is described from a rainforest habitat at Parque Nacional de Serra das Lontras, municipality of Arataca, southern Bahia, Brazil. Dendrophryniscus oreites sp. nov. is related to the Atlantic forest brevipollicatus group by hand morphology, skin texture, ventral coloration and bromelicolous habits. The new species differs from related species by having a larger size, warty skin, inner finger reduced with presence of a dark nuptial pad in males, and a yellowish coloration with discrete dorsal pattern. This discovery highlights the importance of southern Bahia in terms of conservation, and for our understanding of the evolution of the frog diversity within the Atlantic Rainforest.
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A anurofauna do estado de São Paulo, nas últimas oito décadas, tem sido foco do estudo de importantes grupos de pesquisa em anfíbios anuros. Porém, pesquisas realizadas com comunidades na área da Depressão Periférica do centro-oeste paulista ainda são escassas. A fim de trazer novas informações sobre essa região, nosso objetivo foi inventariar a anurofauna de uma área na Depressão Periférica, associando os resultados com dados da literatura e confrontando os mesmos com aqueles conhecidos para a anurofauna no altiplano da Cuesta de Botucatu. O inventário foi realizado a partir dos dados obtidos em 24 dias de amostragem, decorridos 13 meses de coleta (dezembro de 2008 a dezembro de 2009). Os anuros foram amostrados em potenciais sítios reprodutivos, pelos métodos de encontro visual e busca auditiva. Foram registradas 29 espécies distribuídas em 12 gêneros e seis famílias. Apesar da maioria das espécies serem predominantemente de áreas abertas, consideramos a riqueza elevada, e associamos essa riqueza à existência dos remanescentes de mata nos interflúvios. Entretanto, apesar da presença desses remanescentes, a ocorrência de espécies associadas exclusivamente a essas áreas foi pequena, se comparada aos fragmentos no altiplano, fato que aparentemente está associado às diferenças existentes entre os fragmentos contidos nos interflúvios e os fragmentos do altiplano. A atividade dos anfíbios foi concentrada no período quente e úmido, diminuindo à medida que se aproxima o ápice da estação fria e seca. Com base na análise de similaridade, observou-se a formação de agrupamentos com alta sobreposição. Entre esses agrupamentos, destacaram-se aqueles formados por espécies com atividade de vocalização prolongada, mas que diferiram quanto ao período de maior atividade (início e final da estação chuvosa) bem como, aqueles constituídos por espécies com período de vocalização mais curto, restrito a poucos dias, e que também diferiram no mês de pico de atividade (início e final da estação chuvosa). Com isso acreditamos que as diferenças quanto à distribuição temporal dos organismos da comunidade sejam importantes na partilha de recursos e no ajuste das espécies, fato que contribuiu para o elevado número de anfíbios observados e na coexistência dos táxons na área de estudo.
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A new species of Proceratophrys is described from the highlands of northeastern Brazil. Molecular and morphological data suggests that Proceratophrys redacta sp. nov. is sister to P. minuta, and related to P. schirchi and P. cristiceps. The new species is diagnosed by its small size, absence of rostral and palpebral appendages, sagittal ridges interrupted, absence of postocular swellings, snout vertical in profile and dorsal coloration lacking distinct ocelli. The new species represents another example of endemism for the genus Proceratophrys in Chapada Diamantina region, and of another appendageless small-sized species associated with highlands. The phylogenetic results indicate that current morphological groupings in Proceratophrys may not represent natural groups.
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We characterize divergence times, intraspecific diversity and distributions for recently recognized lineages within the Hyla arborea species group, based on mitochondrial and nuclear sequences from 160 localities spanning its whole distribution. Lineages of H. arborea, H. orientalis, H. molleri have at least Pliocene age, supporting species level divergence. The genetically uniform Iberian H. molleri, although largely isolated by the Pyrenees, is parapatric to H. arborea, with evidence for successful hybridization in a small Aquitanian corridor (southwestern France), where the distribution also overlaps with H. meridionalis. The genetically uniform H. arborea, spread from Crete to Brittany, exhibits molecular signatures of a postglacial range expansion. It meets different mtDNA clades of H. orientalis in NE-Greece, along the Carpathians, and in Poland along the Vistula River (there including hybridization). The East-European H. orientalis is strongly structured genetically. Five geographic mitochondrial clades are recognized, with a molecular signature of postglacial range expansions for the clade that reached the most northern latitudes. Hybridization with H. savignyi is suggested in southwestern Turkey. Thus, cryptic diversity in these Pliocene Hyla lineages covers three extremes: a genetically poor, quasi-Iberian endemic (H. molleri), a more uniform species distributed from the Balkans to Western Europe (H. arborea), and a well-structured Asia Minor-Eastern European species (H. orientalis).
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The survival of threatened species as the European tree frog (Hyla arborea) is strongly dependent on the genetic variability within populations, as well as gene flow between them. In Switzerland, only two sectors in its western part still harbour metapopulations. The first is characterised by a very heterogeneous and urbanized landscape, while the second is characterised by a uninterrupted array of suitable habitats. In this study, six microsatellite loci were used to establish levels of genetic differentiation among the populations from the two different locations. The results show that the metapopulations have: (i) weak levels of genetic differentiation (FST within metapopulation ≈ 0.04), (ii) no difference in levels of genetic structuring between them, (iii) significant (p = 0.019) differences in terms of genetic diversity (Hs) and observed heterozygozity (Ho), the metapopulation located in a disturbed landscape showing lower values. Our results suggest that even if the dispersal of H. arborea among contiguous ponds seems to be efficient in areas of heterogeneous landscape, a loss of genetic diversity can occur.
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Documenting and preserving the genetic diversity of populations, which conditions their long-term survival, have become a major issue in conservation biology. The loss of diversity often documented in declining populations is usually assumed to result from human disturbances; however, historical biogeographic events, otherwise known to strongly impact diversity, are rarely considered in this context. We apply a multilocus phylogeographic study to investigate the late-Quaternary history of a tree frog (Hyla arborea) with declining populations in the northern and western part of its distribution range. Mitochondrial and nuclear polymorphisms reveal high genetic diversity in the Balkan Peninsula, with a spatial structure moulded by the last glaciations. While two of the main refugial lineages remained limited to the Balkans (Adriatic coast, southern Balkans), a third one expanded to recolonize Northern and Western Europe, loosing much of its diversity in the process. Our findings show that mobile and a priori homogeneous taxa may also display substructure within glacial refugia ('refugia within refugia') and emphasize the importance of the Balkans as a major European biodiversity centre. Moreover, the distribution of diversity roughly coincides with regional conservation situations, consistent with the idea that historically impoverished genetic diversity may interact with anthropogenic disturbances, and increase the vulnerability of populations. Phylogeographic models seem important to fully appreciate the risks of local declines and inform conservation strategies.
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This survey began in response to widespread interest of declines in amphibians. More recently, a comprehensive statewide planning group discovered 44% of Iowa’s herpetofauna (amphibians and reptiles) to be of special concern. In response to these concerns, the Iowa Department of Natural Resources Wildlife Diversity Program (WDP) initiated an auditory survey for calling anurans to determine geographic distributions within the state. This survey has established itself as an extensive, long term monitoring program. This 2005 report is the second edition since the first report of this survey was shared in 1998 by then program biologist Lisa Hemesath. The goals of the survey are to: (1) determine the distributions of Iowa’s anuran species, (2) determine population trends for each species, and (3) promote education about aquatic life by using volunteers to conduct the survey. In addition to Iowa, volunteer-based auditory surveys for frogs and toads are currently being used in the Midwest by Wisconsin, Minnesota, Missouri, and Illinois.
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Sex-chromosome differentiation was recently shown to vary among common frog populations in Fennoscandia, suggesting a trend of increased differentiation with latitude. By rearing families from two contrasted populations (respectively, from northern and southern Sweden), we show this disparity to stem from differences in sex-determination mechanisms rather than in XY-recombination patterns. Offspring from the northern population display equal sex ratios at metamorphosis, with phenotypic sexes that correlate strongly with paternal LG2 haplotypes (the sex chromosome); accordingly, Y haplotypes are markedly differentiated, with male-specific alleles and depressed diversity testifying to their smaller effective population size. In the southern population, by contrast, a majority of juveniles present ovaries at metamorphosis; only later in development do sex ratios return to equilibrium. Even at these later stages, phenotypic sexes correlate only mildly with paternal LG2 haplotypes; accordingly, there are no recognizable Y haplotypes. These distinct patterns of gonadal development fit the concept of 'sex races' proposed in the 1930s, with our two populations assigned to the 'differentiated' and 'semi-differentiated' races, respectively. Our results support the suggestion that 'sex races' differ in the genetic versus epigenetic components of sex determination. Analysing populations from the 'undifferentiated race' with high-density genetic maps should help to further test this hypothesis.
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Le but du présent travail est d’apporter la preuve paléontologique mettant en évidence que le clade Raninoida était bien établi dans le Néotropique durant la période Crétacée, où il était représenté par les plus anciennes familles ou par quelques–uns des plus anciens membres des plus anciennes familles. Je décris des taxa raninoïdiens ou similaires, incluant Archaeochimaeridae n. fam. et Archaeochimaera macrophthalma n. gen. n. sp., du Cénomanien supérieur (~95 Ma.) de Colombie (Chapitre 3), Planocarcinus n. gen., Planocarcinus olssoni (Rathbun, 1937) n. comb. et Notopocorystes kerri n. sp., de l’Aptien supérieur (~115 Ma.) de Colombie (Luque et al., accepté) (Chapitre 2). Ces taxa nouveaux, plus la présence de Cenomanocarcinus vanstraeleni Stenzel, 1945, dans l’Albien supérieur de Colombie (Vega et al., 2010), et d’Araripecarcinus ferreirai Martins–Neto, 1987, dans l’Albien du Brésil (Luque et al., en cours) (Chapitre 4), représentent certains des plus anciens signalements de quatre des sept familles raninoïdiennes, au moins, connues à ce jour. La nouvelle famile Archaeochimaeridae se présente comme le groupe frère du clade Raninidae + clade Symethidae. Cependant, la combinaison unique de caractères primitifs, dérivés et homoplasiques est inégalable chez les Raninoida, et, en fait, chez les autres sections de crabes podotrèmes. Alors que les taxa raninoïdiens du Crétacé sont bien connus aux latitudes élevées, les signalements en Amérique du Sud tropicale sont rares et épars, avec pour résultat de considérables distorsions pour traiter des importantes questions biogéographiques et phylogénétiques. Sur la base de données taxonomiques, paléobiogéographiques et cladistiques, une ré–appréciation des toute premières distributions spatio–temporelle des “crabes grenouilles” est proposée, avec pour objet de contribuer à une plus large compréhension de la diversité, phylogénie et évolution des premiers brachyoures au cours des âges.