Abstract
Eleven specimens of Iheringichthys labrosus, collected from the Tibagi River (Londrina, Paraná, Brazil) were analyzed cytogenetically, and were found to have a diploid chromosome number of 56, with a karyotype of 32M+8SM+6ST+10A and fundamental number (FN) of 102. In addition, supernumerary chromosomes or Bs varying from 0 to 3 were detected. C-banding revealed heterochromatin distributed mainly in telomeric regions, with a pair strongly stained on both telomeres. The B-chromosomes were totally heterochromatic. The restriction endonuclease (RE) AluI produced a band pattern almost similar to C-banding, and B-chromosomes showed no target sequences for RE.
