title: First cytogenetic studies of the genus Heptapterus (Actinopterygii, Siluriformes): karyotype differentiation and review of cytogenetic data on the Heptapteridae family.
abstract: The Neotropical fish Heptapterus mustelinus, collected in the Pindorama stream of the upper Paraná River basin (Brazil), was studied cytogenetically, verifying 54 chromosomes (26m + 18m + 4st + 6a). This diploid number has not been reported among the Heptapteridae that have been studied to date. Unlike most species of the family, there were multiple Ag-nucleolar organizer regions (NOR) and heterochromatin present in the centromeric region of most of the chromosomes of the complement, being Chromomycin A(3) (CMA(3)(+))/4',6-diamidino-2-phenylindole (DAPI(-)) in nine chromosomal pairs, besides the one that coincides with the Ag-NORs. The data presented in this work reveal a different path in the karyotypic evolution of H. mustelinus when compared to the others Heptapteridae genera.
authors.affiliation: Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, 85819-110, Rua Universitária 2069, Cascavel, PR, Brazil.
authors.forename: C F
authors.initials: CF
authors.lastname: Yano
authors.forename: V P
authors.initials: VP
authors.lastname: Margarido
mesh_terms: D000818:Animals; D002397:Catfishes / Q000235:genetics*; D002875:Chromosomes / Q000235:genetics*; D003582:Cytogenetics; D059785:Karyotype