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Registros recuperados: 10 | |
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Frazão,Luciana; Oliveira,Maria Ermelinda; Menin,Marcelo; Campos,Juliana; Almeida,Alexandre; Kaefer,Igor L.; Hrbek,Tomas. |
Abstract: Snakes are a diverse group of terrestrial vertebrates of the order Squamata. Despite that, in the Amazonian biome, information about distribution and identification of snakes is limited when compared to other groups. Additionally, in Amazonia there is a sampling bias towards areas geographically close to urban centers and more densely populated areas. This in turn leads to false distribution gaps in poorly accessible areas of Amazonia. In this article we report the composition of snake assemblages in six areas of the Brazilian Amazonia, based on field sampling conducted over four years using standardized methods. We sampled 70 species from eight families: Typhlopidae (n=1), Leptotyphlopidae (n=1), Anillidae (n=1), Boidae (n=5), Colubridae (n=15),... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon Basin; Brazil; Ophidia; Sampling methods; Squamata. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032020000100207 |
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Vasconcelos,William R.; Hrbek,Tomas; Silveira,Ronis da; Thoisy,Benoit de; Marioni,Boris; Farias,Izeni P.. |
The genetic structure of Caiman crocodilus was investigated using a 1085 bp mtDNA fragment of the cytochrome b gene. Inferences were based on 125 individuals from nine localities in Peru, Brazil and French Guiana. With the exception of Mamirauá Lake, Anavilhanas Archipelago and the Tapará Community which show a signal of demographic expansion, the sampled localities are in a mutation-drift genetic equilibrium. Divergence between the Amazon basin and extra-Amazon basin localities is significant; however, inference from Nested Clade Analysis cannot distinguish between continuous range expansion, long distance colonization or past fragmentation; however, past fragmentation is unlikely due to low number of mutational steps separating these two regions. The... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Genetic structure; Phylogeography; Genetic diversity; Demographic expansion; Cytochrome b; Caiman crocodilus. |
Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000200006 |
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Banhos,Aureo; Hrbek,Tomas; Gravena,Waleska; Sanaiotti,Tânia; Farias,Izeni P.. |
We report the characterization and optimization of 45 heterologous microsatellite loci, and the development of a new set of molecular sex markers for the conservation and management of the Neotropical harpy eagle (Harpia harpyja L. 1758). Of the 45 microsatellites tested, 24 were polymorphic, six monomorphic, 10 uncharacterizable due to multiple bands and five did not amplify. The observed gene diversity of the analyzed sample of H. harpyja was low and similar to that of other threatened Falconiformes. While a high proportion of the microsatellite markers were highly variable, individuals of H. harpyja could be differentiated by a joint analysis of just three (p = 2.79 x 10-4) or four markers (p = 2.89 x 10-5). Paternity could be rejected with 95.23% and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Conservation genetics; Harpia harpyja; Microsatellites; Raptors; Sex markers. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000100025 |
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Hrbek,Tomas; Farias,Izeni Pires. |
We sequenced the complete mitochondrial genome of the pirarucu, Arapaima gigas, the largest fish of the Amazon basin, and economically one of the most important species of the region. The total length of the Arapaima gigas mitochondrial genome is 16,433 bp. The mitochondrial genome contains 13 protein-coding genes, two rRNA genes and 22 tRNA genes. Twelve of the thirteen protein-coding genes are coded on the heavy strand, while nad6 is coded on the light strand. The Arapaima gene order and content is identical to the common vertebrate form, as is codon usage and base composition. Its control region is atypical in being short at 767 bp. The control region also contains a conserved ATGTA motif recently identified in the Asian arowana, three conserved... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pirarucu; Mitogenomics; Amazon basin. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200024 |
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L.,María Doris Escobar; Farias,Izeni P.; B.,Donald C. Taphorn; Landines,Miguel; Hrbek,Tomas. |
The arowanas, fishes of Gondwanan origin, are represented in South America by the genus Osteoglossum. All species were initially reported as being exclusive to the Amazon region, with O. ferreirai restricted to the Negro River basin and O. bicirrhosum to the Amazon and Essequibo Rivers basin. Starting in the mid 1970's it was reported that O. ferreirai also occurs in the Orinoco River basin. In all regions the arowanas assumed significant socio-economic importance due to their popularity in the international ornamental fish trade, leading to over-exploitation of both species in some areas. The Orinoco populations are particularly heavily exploited, and thus conservation and management measures are needed. Both depend on the clarification of taxonomic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aruana; Biological introduction; Black arowana; Silver arowana. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000200335 |
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Farias,Izeni Pires; Leão,Adam; Almeida,Yane Santos; Verba,Júlia Tovar; Crossa M.,Marcelo; Honczaryk,Alexandre; Hrbek,Tomas. |
Arapaima gigas is one of the largest freshwater fishes of the world. It is socially monogamous, forming pairs, constructing a nest and providing parental care. We performed a paternity analysis under three scenarios in captive, semi-natural and natural areas using 10 microsatellite markers. As a positive control, we analyzed three pairs and their offspring isolated individually in artificial breeding ponds (a priori very high probability of monogamy). We then analyzed two samples of offspring from large artificial ponds with multiple adults but only one reproductive pair (a priori high probability of monogamy), two samples from semi-natural breeding station with multiple adults but only one reproductive pair (a priori high probability of monogamy), and a... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mate choice; Microsatellites; Multiple paternity; Pirarucu; Polygamy. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252015000100195 |
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Bittencourt,Pedro Senna; Machado,Valéria Nogueira; Marshall,Bruce Gavin; Hrbek,Tomas; Farias,Izeni Pires. |
ABSTRACT Neon tetras (Paracheirodon spp.) are three colorful characid species with a complicated taxonomic history, and relationships among the species are poorly known. Molecular data resolved the relationships among the three neon tetras, and strongly supported monophyly of the genus and its sister taxon relationship to Brittanichthys. Additionally, the sister-taxon relationship of the rummy-nose tetras Hemigrammus bleheri and Petitella georgiae was strongly supported by molecular and morphological data. Therefore, we propose to transfer the rummy-nose tetras H. bleheri and H. rhodostomus to the genus Petitella. Furthermore, Petitella georgiae is likely to be a species complex comprised of at least two species. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Blood-red tetras; Characids; Neon tetras; Phylogeny; Rummy-nose tetras. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252020000200213 |
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Ota,Rafaela Priscila; Machado,Valéria Nogueira; Andrade,Marcelo C.; Collins,Rupert A.; Farias,Izeni Pires; Hrbek,Tomas. |
ABSTRACT Pacus of the genus Myloplus represent a formidable taxonomic challenge, and particularly so for the case of M. asterias and M. rubripinnis, two widespread and common species that harbor considerable morphological diversity. Here we apply DNA barcoding and multiple species discovery methods to find candidate species in this complex group. We report on one well-supported lineage that is also morphologically and ecologically distinct. This lineage represents a new species that can be distinguished from congeners by the presence of dark chromatophores on lateral-line scales, which gives the appearance of a black lateral line. It can be further diagnosed by having 25-29 branched dorsal-fin rays (vs. 18-24), 89-114 perforated scales from the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: COI gene; Cryptic species; Myloplus asterias; Myloplus rubripinnis; Neotropical. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252020000100214 |
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Registros recuperados: 10 | |
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