Molecular biogeography of the Neotropical fish Hoplias malabaricus (Erythrinidae:Characiformes) in the Igua？u, Tibagi, and Paraná Rivers

hoplias malabaricus, the common trahira, extended its range into the igua？u river sometime in the last decades. to determine levels of genetic differentiation in neighboring basins of this nominal taxon, as well as to unveil the source of the invading population, we analyzed patterns of similarity of rapd-pcr genomic markers of samples from paraná, igua？u and tibagi rivers. the high genetic diversity of samples from the paraná and tibagi rivers suggested strong population structuring or even the occurrence of undescribed species. all alleles of the sample from the headwaters of tibagi river were present in the sample from the igua？u river, which suggests that the former population or another population with similar genetic makeup, may be the source of the trahiras of the igua？u river.