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| Artoni,Roberto Ferreira; Shibatta,Oscar Akio; Gross,Maria Claudia; Schneider,Carlos Henrique; Almeida,Mara Cristina de; Vicari,Marcelo Ricardo; Bertollo,Luiz Antonio Carlos. |
| Four populations of Astyanax aff. fasciatus of the upper rio Tibagi (municipal district of Ponta Grossa, Paraná State, Brazil), had their karyotypes and morphometry analyzed. The cytogenetic data show the occurrence of distinct karyotypes (cytotypes), here named cytotype A, with 2n=48 chromosomes (6m+18sm+14st+10a), cytotype B, with 2n=50 chromosomes (8m+18sm+14st+10a) and cytotype C, with 2n=50 chromosomes (8m+18sm+14st+10a). The distribution pattern of the constitutive heterochromatin was very similar between cytotypes A and B, but diverged in relation to cytotype C. Distinct cytotypes may occur in sympatry in the upper rio Tibagi region, with the exception of the Furna 2 sample, which presents cytotype A exclusively. In addition, a specimen with 2n=49... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tetra; Morphometrics; Karyotype; Sympatry; Cryptic species. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252006000200005 |
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| Benzaquem,Denise Corrêa; Feldberg,Eliana; Porto,Jorge Ivan Rebelo; Gross,Maria Claudia; Zuanon,Jansen Alfredo Sampaio. |
| Karyotypes of six cichlid species of the genus Crenicichla were investigated. The species C. cincta, C. inpa, C. reticulata, C. lugubris, and C. cf. johanna were collected from Amazon basin, and C. britskii was collected from the Paraná-Paraguai basin. All of the analysed species showed 2n = 48 chromosomes; however, C. cincta, C. lugubris, C. cf. johanna, and C. britskii had a karyotype formula of 8M-SM+40ST-A, FN = 56, while C. inpa and C. reticulata exhibited the formula 6M-SM+42ST-A, FN = 54. Analysis of active Ag-NORs revealed two NOR-bearing chromosomes in all species; however, theses cistrons were located on different chromosome pairs and/or in different chromosome locations in each species. This condition bears evolutionary significance, since it is... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Karyotype; Pike cichlid; Chromosome marker; Amazon. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200016 |
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| Gross,Maria Claudia; Schneider,Carlos Henrique; Matiello,Mara Cristina de Almeida; Leite,Maysa de Lima; Bertollo,Luiz Antonio Carlos; Artoni,Roberto Ferreira. |
| Morphological and chromosomal markers were used to infer the structure and genetic variability of a population of fish of the genus Astyanax, geographically isolated at sinkhole 2 of Vila Velha State Park, Paraná, Brazil. Two morphotypes types were observed, the standard phenotype I and phenotype II which showed an anatomical alteration probably due to an inbreeding process. Fluctuating asymmetry (FA) analysis of different characters showed low levels of morphological variation among the population from sinkhole 2 and in another population from the Tibagi river (Paraná, Brazil). The Astyanax karyotype was characterized in terms of chromosomal morphology, constitutive heterochromatin and nucleolar organizer regions. Males and females presented similar... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish; Astyanax sp.; Fluctuating asymmetry; Karyotype structure; Triploidy; Genetic conservation. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000400011 |
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