669 resultados para FROG


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Predation is a primary driver of tadpole assemblages, and the activity rate is a good predictor of the tadpoles' tolerance for predation risk. The conflicting demands between activity and exposure to predation can generate suboptimal behaviours. Because morphological components, such as body colouration, may affect the activity of tadpoles, we predict that environmental features that enhance or match the tadpole colouration should affect their survival or activity rate in the presence of a predator. We tested this prediction experimentally by assessing the mortality rate of tadpoles of Rhinella schneideri and Eupemphix nattereri and the active time on two artificial background types: one bright-coloured and one black-coloured. We found no difference in tadpole mortality due to the background type. However, R. schneideri tadpoles were more active than E. nattereri tadpoles, and the activity of R. schneideri was reduced less in the presence of the predator than that of E. nattereri. Although the background colouration did not affect the tadpole mortality rate, it was a stimulus that elicited behavioural responses in the tadpoles, leading them to adjust their activity rate to the type of background colour. © 2013 Dipartimento di Biologia, Università degli Studi di Firenze, Italia.

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Many species of tropical amphibians are restricted to very small ranges, and this microendemism coupled with ongoing habitat loss and susceptibility to emerging pathogens imperils the long-term persistence of these species. Incomplete taxonomic and distributional knowledge may obscure conservation assessment, particularly in putatively widespread species that are typically considered to be of Least Concern in Red List assessments, but that in fact may constitute complexes of partly microendemic species. Such is the case in the Steindachner's Robber Frog, Ischnocnema guentheri which, together with the recently recognized Ischnocnema henselii, is thought to occupy most of the Brazilian Atlantic Forest. To test whether these taxa may constitute a species complex of range-restricted and thus potentially threatened species, we analyzed 160 samples of I. guentheri and/or I. henselii for two molecular markers, 16S rRNA (16S) and recombination activation gene 1 (RAG1). To verify the monophyly of the complex, closely related species were also included in the 16S analysis. Congruent evidence from the molecular data and from analyses of advertisement calls support the existence of six distinct species within the complex: I. guentheri and I. henselii as well as four candidate new species. The lineages are distributed as a mosaic in the Atlantic Forest and are sympatric at some localities without indication of admixture. Their phylogeographical pattern partially agrees with paleo-models for the Atlantic Forest, but also suggests the existence of micro-refugia in less stable areas. I. guentheri, previously considered to be widespread, was found only in its type locality, a reserve within the urban area of Rio de Janeiro city. Although none of the species studied appears highly threatened with extinction, we recommend their IUCN threat status to be re-evaluated carefully for the next comprehensive update of the Red List of Brazil's amphibians. © 2013 Springer Science+Business Media Dordrecht.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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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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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Fonoaudiologia - FFC

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Pós-graduação em Fonoaudiologia - FFC

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)