Data/hora: 10/06/2024 02:35:25

Provedor de dados: | 83
País: | Brazil
Título: | Astyanax aff. fasciatus Cuvier, 1819 (Teleostei; Characidae): evidences of a species complex in the upper rio Tibagi basin (Paraná, Brazil)
Autores: | Artoni,Roberto Ferreira; Shibatta,Oscar Akio; Gross,Maria Claudia; Schneider,Carlos Henrique; Almeida,Mara Cristina de; Vicari,Marcelo Ricardo; Bertollo,Luiz Antonio Carlos.
Data: | 2006-06-01
Ano: | 2006
Palavras-chave: | Tetra; Morphometrics; Karyotype; Sympatry; Cryptic species.
Resumo: | 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 chromosomes (7m+18sm+14st+10a) was also found and, by the characteristics presented, may be a consequence of a rare hybridization event between cytotypes A and B. The morphometric analyses of canonical variates indicate a consistent isolation of the Furna 2 sample, while the other samples seem to be superimposed, indicating a possible gene flow or even a recent isolation event. This model points to a probable complex of cryptic species in the studied region.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252006000200005
Editor: | Sociedade Brasileira de Ictiologia
Relação: | 10.1590/S1679-62252006000200005
Formato: | text/html
Fonte: | Neotropical Ichthyology  v.4 n.2 2006
Fonte: | info:eu-repo/semantics/openAccess