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Padrões Citogenéticos de Duas Espécies de ciclídeos de Bacias do Semi-Árido do Brasil: Crenicichla menezesi e Cichlasoma orientale

2014; UNIVERSIDADE FEDERAL DO AMAPÁ; Volume: 4; Issue: 4 Linguagem: Inglês

10.18561/2179-5746/biotaamazonia.v4n4p33-39

ISSN

2179-5746

Autores

Wagner Franco Molina, George Pacheco, Waldir M. Berbel‐Filho,

Tópico(s)

Animal Genetics and Reproduction

Resumo

The family Cichlidae is considered a model for studies of adaptive radiation among vertebrates. However, cytogenetic data focusing to understanding the karyotype evolution of this family are still incipient, particularly for species of semi-arid region of northeastern of Brazil. This study presents the first karyotypic information of neotropical species Crenicichla menezesi and Cichlasoma orientale , by use of conventional staining, C-banding, silver staining and staining with base-specific fluorochromes. Both species have 2n=48 chromosomes, with some distinctions in relation to karyotype, once C. menezesi displays 4m+44 st/a (NF=52) and C. orientale 6sm+10st+32 (N=54). Ribosomal sites are unique, located on the short arms of the first pair (m) in C. menezesi and on third pair (sm) in C. orientale . In both species the heterochromatic blocks are concentrated in the centromeric and pericentromeric regions and conspicuously in colocalization with NORs (CMA + /DAPI - ). Among cichlids, the Neotropical clade reveals a numerical chromosomal conservatism (2n=48), but that includes a varied evolutionary dynamics as the structural patterns of the karyotype. The two species analyzed, Crenicichla menezesi and Cichlasoma orientale , typical species of semi-arid regions reinforce this condition. Keywords: Karyotype diversity; chromosomal evolution; fish cytogenetic.

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