Identification and chromosome mapping of repetitive elements in the Astyanax scabripinnis (Teleostei: Characidae) species complex.

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Barbosa, Patrícia; de Oliveira, Luiz Antonio; Pucci, Marcela Baer; Santos, Mateus Henrique; Moreira-Filho, Orlando; Vicari, Marcelo Ricardo; Nogaroto, Viviane; de Almeida, Mara Cristina; Artoni, Roberto Ferreira

2015-02-01

Most part of the eukaryotic genome is composed of repeated sequences or multiple copies of DNA, which were considered as "junk DNA", and may be associated to the heterochromatin. In this study, three populations of Astyanax aff. scabripinnis from Brazilian rivers of Guaratinguetá and Pindamonhangaba (São Paulo) and a population from Maringá (Paraná) were analyzed concerning the localization of the nucleolar organizer regions (Ag-NORs), the As51 satellite DNA, the 18S ribosomal DNA (rDNA), and the 5S rDNA. Repeated sequences were also isolated and identified by the Cot - 1 method, which indicated similarity (90%) with the LINE UnaL2 retrotransposon. The fluorescence in situ hybridization (FISH) showed the retrotransposon dispersed and more concentrated markers in centromeric and telomeric chromosomal regions. These sequences were co-localized and interspaced with 18S and 5S rDNA and As51, confirmed by fiber-FISH essay. The B chromosome found in these populations pointed to a conspicuous hybridization with LINE probe, which is also co-located in As51 sequences. The NORs were active at unique sites of a homologous pair in the three populations. There were no evidences that transposable elements and repetitive DNA had influence in the transcriptional regulation of ribosomal genes in our analyses.

O fator de condição de peixes de duas bacias no Estado de São Paulo, Sudeste do Brasil - DOI: 10.4025/actascibiolsci.v27i1.1368 The condition factor of fishes from two river basins in São Paulo state, Southeast of Brazil - DOI: 10.4025/actascibiolsci.v27i1.1368

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Leandro Muller Gomiero

2005-03-01

Full Text Available Neste trabalho foi obtido o fator de condição relativo de Hypostomus strigaticeps, Astyanax altiparanae, Astyanax scabripinnis, Astyanax fasciatus, Astyanax sp1., Characidium aff. zebra, Piabina argentea, Hypostomus ancistroides, Hypostomus sp1., Parodon tortuosus, Serrapinus heterodon e Bryconamericus sp. da APA de São Pedro e Analândia (22°-23°S e 47°30’-48°30’W. O fator de condição fornece indicações do estado de bem estar do peixe no ambiente. Para a comparação de espécies distintas foi utilizado o fator de condição relativo, relacionando as variações deste fator ao longo do ano e conseqüentes alterações fisiológicas dos peixes. O fator de condição relativo mostrou-se eficaz como ferramenta para evidenciar as mudanças nas condições dos peixes durante as estações do anoThis work describes the relative condition factor of the Hypostomus strigaticeps, Astyanax altiparanae, Astyanax scabripinnis, Astyanax fasciatus, Astyanax sp1., Characidium aff. zebra, Piabina argentea, Hypostomus ancistroides, Hypostomus sp1., Parodon tortuosus, Serrapinus heterodon, and Bryconamericus sp., of the APA of São Pedro and Analândia (22° - 23°S and 47°30’ - 48°30’W. The condition factor provides information about the physical state of the animal in the environment. In order to compare different species, the relative condition factor was used. Variations in this factor were correlated with variations through the year and with subsequent alterations in the physiological state of the fishes. The relative condition factor was shown to be efficient in indicating changes in fish condition throughout the year

Ichthyofauna from the Emas National Park region: composition and structure

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E. Benedito-Cecilio

Full Text Available The relationship between habitats and the ichthyofauna composition in the Parque Nacional das Emas (PNE and adjacent areas (the Araguaia and Sucuriú rivers are provided and could be applied in determining the Park's future zoning. Samples of the ichthyofauna and limnological parameters were obtained during both dry (September 1999 and wet (December 1999 seasons. Ichthyofauna collections resulted in the capture of 4,740 specimens of 22 species. The most abundant species in the Araguaia River during the two sampling seasons were Astyanax sp. 2 and Hasemania sp. In the Sucuriú River and PNE, Astyanax scabripinnis cf. paranae and Hoplias aff. malabaricus were the most frequent species. The largest number of species and diversity index were recorded for the Araguaia River. However, sound management policies require more detailed studies on the fish communities of the Cerrado biome.

A comunidade de peixes de um riacho de Floresta com Araucária, alto rio Iguaçu, sul do Brasil The fish community in an Araucaria Forest stream, upper Iguaçu River basin, southern Brazil

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Vinicius Abilhoa

2008-06-01

Full Text Available Foram avaliadas a composição, a dieta, as táticas alimentares e ocupação espacial da ictiofauna em um pequeno riacho dentro de um remanescente de Floresta com Araucária. Seis espécies de peixes foram coletadas, pertencentes a três ordens e quatro famílias, totalizando 110 exemplares. No ambiente de corredeira foram coletados e observados apenas Trichomycterus castroi Pinna, 1992 and Trichomycterus davisi Haseman, 1911, enquanto que no ambiente de remanso foram observados e capturados exemplares de Astyanax aff. scabripinnis (sensu Eigenmann, 1921, Astyanax totae Haluch & Abilhoa, 2005, Trichomycterus castroi Pinna, 1992, T. davisi, Phalloceros caudimaculatus (Hensel, 1868 e Jenynsia eigenmanni Haseman, 1911. Dezoito itens alimentares de origem autóctone, seis de alóctone e três de origem incerta foram identificados e tiveram sua freqüência de ocorrência calculada. Uma grande quantidade de itens exclusivos foi registrada, todavia os insetos constituíram a base alimentar mais importante, principalmente na forma de fragmentos e estágios imaturos (larvas e pupas, o que permitiu inferências a respeito de sobreposição alimentar. As espécies registradas no riacho foram classificadas em quatro guildas tróficas e quatro grupos funcionais. As espécies estudadas são capazes de utilizar diversos recursos alimentares e microambientes, o que é favorecido provavelmente pelo seu pequeno porte. O remanescente florestal estudado exerce grande importância no fornecimento de alimento, hábitats e refúgios, fatores importantes para manutenção da biota aquática.The species composition, diet, feeding tactics, and spatial occupation of fishes in a headwater stream which flows within a remaining fragment of Araucaria Forest were studied. One hundred and ten fishes of six species were collected, members of three orders and four families. In riffle areas, only Trichomycterus castroi Pinna, 1992 and Trichomycterus davisi Haseman, 1911 were