Cytogenetic Characterization of Two Species of the Genus Crenicichla (Pisces, Cichlidae)

Abstract

The two species of genus Crenicichla showed the same diploid number, 2n=48 chromosomes with different karyotypes. The diploid number of 48 chromosomes is proposed as a conserved characteristics through the karyotypic evolution of cichlids. The NOR, coinciding with the secondary constriction, was detected on the short arm of the first metacentric chromosome pair in two species. The treatment by chromomycin fluorochrome coincided with the NOR and through the DAPI fluorochrome technique it was detected no marking, being negative on the secondary constriction. The pattern of constitutive heterochromatin was very similar among these species, being observed preferentially in centromeric regions, as well as on the secondary constriction.