Hexaploidy in yellowfish species (Barbus, Pisces, Cyprinidae) from southern Africa

Five small-scaled yellow fish (large Burbus spp.) from southern Africa are shown to have modal 148 or 150 chromosomes. Themajority ofcyprinid species have 2N = 50 chromosomes, indicating that the yellow fish karyotype is hexaploid in origin. However, as there is no indication that the species are unisexual or that normal reproduction occurs by any means other than bisexual fertilization, the yellowfish karyotype is considered to have reverted to a diploid condition.