Comparative cytogenetics between three characidae fish species from the são francisco river basin

Abstract

Characidae is one of the predominant fish groups in the Neotropical region with approximately 30 highly diversified subfamilies, probably not representing a monophyletic group. Three Characidae species from the São Francisco River basin (Três Marias, MG, Brazil) were analyzed: Hasemania nana with 2n=50 chromosomes (8m+42sm), Orthospinus franciscencis with 2n=50 chromosomes (22m+20sm+2st+6a) and Piabina argentea with 2n=52 chromosomes (8m+14sm+16st+14a), all the species showing no differences between male and female karyo-types. The heterochromatin was preferentially distributed in the centromeric region of the chromosomes and the Ag-NORs were located in only a single chromosome pair in the three species. The chromosomal data obtained may be useful for the taxonomy and phylogenetic studies in those fish groups. © 2007 Taylor and Francis Group, LLC.