title: Occurrence of B chromosomes in Cyphocharax modestus (Fernández-Yépez, 1948) and Steindachnerina insculpta (Fernández-Yépez, 1948)(Characiformes, Curimatidae) from the Tibagi River basin (Paraná State, Brazil).
abstract: We cytogenetically analyzed 18 individuals of Cyphocharax modestus, and 41 individuals of Steindachnerina insculpta from the Tibagi River basin (Paraná State, Brazil). All the specimens had 2n=54 chromosomes, all meta-submetacentric (M-SM). The presence of 1 or 2 B chromosomes was seen in some individuals of C. modestus of the two sampled populations, showing inter- and intra individual variation. In S. insculpta, B chromosomes were also observed but only in one population, also showing inter- and intra individual variation. C-banding was used to show that the identified B chromosomes were totally heterochromatic in the two examined species.
authors.affiliation: Departamento de Biologia Geral, CCB, Universidade Estadual de Londrina, Londrina, PR, Brazil.
authors.forename: W
authors.initials: W
authors.lastname: Gravena
authors.forename: R
authors.initials: R
authors.lastname: Teribele
authors.forename: L
authors.initials: L
authors.lastname: Giuliano-Caetano
authors.forename: A L
authors.initials: AL
authors.lastname: Dias
mesh_terms: D000818:Animals; D001938:Brazil; D002871:Chromosome Banding; D005260:Female; D005399:Fishes / Q000145:classification / Q000235:genetics*; D014644:Genetic Variation; D006570:Heterochromatin; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D045483:Rivers
chemical_list: D006570:Heterochromatin