Abstract
The order Siluriformes comprises the second largest group of fish in South America, with more than 3,000 species, of which 109 belong to the family Pimelodidae. The diploid number in Pimelodidae ranges from 2n = 50 in Callophysus macropterus, to 2n = 60 chromosomes in Conorhyncus conirostris. The Bergiaria genus (Pimelodidae) includes two species: Bergiaria westermanni and Bergiaria plata…