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)

• Autor(a) principal: Gravena,W.
• Data de Publicação: 2007
• Outros Autores: Teribele,R., Giuliano-Caetano,L., Dias,AL.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Biology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1519-69842007000500014
• topic: supernumerary chromosomes; karyotype; C-banding; fish populations

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.