Interspecific cytogenetic relationships in three species (Acestrohynchinae, Characiformes) reveal the existence of possible cryptic species.

The karyotypes and chromosomal characteristics of three Eigenmann et Kennedy, 1903 species were examined using conventional and molecular protocols. These species had invariably a diploid chromosome number 2n = 50. (Block, 1794) and (Cuvier, 1819) had the karyotype composed of 16 metacentric (m) + 28 submetacentric (sm) + 6 subtelocentric (st) chromosomes while (Schomburgk, 1841) had the karyotype composed of 14m+30sm+6st elements.