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| Castro,Jonathan P.; Moura,Maurício O.; Moreira-Filho,Orlando; Shibatta,Oscar A.; Santos,Mateus H.; Nogaroto,Viviane; Vicari,Marcelo R.; Almeida,Mara C. de; Artoni,Roberto F.. |
| Two populations of the Astyanax scabripinniscomplex, isolated by a waterfall with over 100 meters depth and inhabiting different altitudes of the same river (1850 m a.s.l. and 662 m a.s.l.) were compared in reproductive data, geometric morphometry, tooth morphology, anal-fin rays counts, and karyotype, in order to test the hypothesis of speciation between the two populations. The results in the geometric morphometry analysis showed differences between the populations. Discriminant function analysis (DFA) and canonical variance analysis revealed sexual dimorphism. Secondary sexual characters, such as hooks in the anal fin rays of the males are absent in the lower altitude population. Both populations had the same macro karyotype structure, except for the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Allopatric populations; Cytogenetics; Evolution; Geometric morphometry; Paraíba do Sul River. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252014000200429 |
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| Domingues,Manoela de S.; Vicari,Marcelo R.; Abilhoa,Vinícius; Wamser,João P.; Cestari,Marta M.; Bertollo,Luiz A. C.; Almeida,Mara C. de; Artoni,Roberto F.. |
| The recently described fish species, Astyanax altiparanae (tetra) is common in the upper rio Paraná basin, and has been reported in the Iguaçu basin. However, its natural origin in the rio Iguaçu is questionable. In the present work, karyotypical and morphological features of two populations of Astyanax altiparanae from the upper rio Tibagi and upper rio Iguaçu were compared. Both populations showed 2n=50 chromosomes and differences in their karyotype formula, NOR-bearing chromosomes and location of heterochromatin. Morphometric data from both populations were analyzed through free-size canonical variables. Cytogenetic and morphological results were mostly coincident showing exclusive markers that reflect their degree of populational isolation. In addition... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tetra; Karyotype evolution; Distribution; Morphometry. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252007000100005 |
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