title: Molecular differentiation of  species of the genus Zungaro (Siluriformes, Pimelodidae) from the Amazon  and Paraná-Paraguay River basins in Brazil.
abstract: Fish  species of the Zungaro genus (Siluriformes, Pimelodidae) are amongst the  largest migratory fish in Latin America and have considerable economic  importance for commercial fishing in Brazil. However, natural populations of this  large catfish are experiencing a severe decline. There are significant  taxonomical inconsistencies for this fish. Two geographically separated species  of the fish were initially described, one endemic in the Amazon and another in  the Paraná-Paraguay River basins. A taxonomic review had recently proposed that  there is only one Zungaro species in Brazil, based on morphological  data. We made a molecular study of Zungaro populations in an attempt to  solve taxonomical inconsistencies and to analyze genetic diversity in natural  populations of this genus. We analyzed two regions of the mitochondrial DNA  (the control region and the ATPase 6 gene region) of individuals sampled from  the Paraná-Paraguay River and Amazon River basins. Analyses based on p-distances  and maximum likelihood phylogenetic models showed a genetic difference between  populations corresponding to different species. Genetic differentiation between Zungaro populations was at the same level as that observed between other  Siluriformes species, using the same DNA sequences. We conclude that Zungaro species of the Paraná-Paraguay River basin do not belong to the same  species found in the Amazon basin. This finding has a significant implication  for conservation of this fish, given that populations are disappearing at a  high rate in the Paraná-Paraguay River basin, mainly due to impoundments.
authors.affiliation: Núcleo de Pesquisas em Limnologia, Ictiologia e Aquicultura, Universidade Estadual de Maringá, Maringá, PR, Brasil. talgeaiex@gmail.com
authors.forename: T A
authors.initials: TA
authors.lastname: Boni
authors.forename: A A
authors.initials: AA
authors.lastname: Padial
authors.forename: S M A P
authors.initials: SM
authors.lastname: Prioli
authors.forename: L C
authors.initials: LC
authors.lastname: Lucio
authors.forename: T C
authors.initials: TC
authors.lastname: Maniglia
authors.forename: T S
authors.initials: TS
authors.lastname: Bignotto
authors.forename: R S
authors.initials: RS
authors.lastname: Panarari-Antunes
authors.forename: R A
authors.initials: RA
authors.lastname: Prioli
authors.forename: A J
authors.initials: AJ
authors.lastname: Prioli
mesh_terms: D000818:Animals; D001938:Brazil; D002397:Catfishes / Q000145:classification* / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D014644:Genetic Variation / Q000502:physiology*; D010802:Phylogeny; D045483:Rivers; D013045:Species Specificity
chemical_list: D004272:DNA, Mitochondrial