%0 Journal Article
%T Cytogenetical analyses in three fish species of the genus Pimelodus(Siluriformes: Pimelodidae) from rio S£¿o Francisco: considerations about the karyotypical evolution in the genus
%A Garcia
%A Caroline
%A Moreira Filho
%A Orlando
%J Neotropical Ichthyology
%D 2005
%I Sociedade Brasileira de Ictiologia
%R 10.1590/S1679-62252005000200006
%X karyotypes and other chromosomal markers were investigated in three species of the catfish genus pimelodus, namely p. fur, p. maculatus and pimelodus sp., from municipality of tr¨ºs marias, minas gerais, brazil, using differential staining techniques (c-banding, silver nitrate and cma3 staining). the diploid chromosome number was 2n = 56 in p. maculatus and pimelodus sp., while in p. fur 2n = 54. the karyotype of p. fur consisted in 32m + 8sm + 6st + 8a with fundamental number (nf) of 100, that of p. maculatus 32m + 12sm + 12a with nf = 112, and that of pimelodus sp. had 32m + 12sm + 6st + 6a with nf = 106.the nucleolar organizer regions (nors) in all three species were invariably detected in telomeres of longer arm of the 20th chromosome pair. these sites were also positive after cma3 and c-banding. no heteromorphic sex chromosomes were detected and c-banding pattern was species specific. inferences about the karyotype differentiation in pimelodus and putative chromosomal rearrangements are hypohesized.
%K fish cytogenetics
%K diploid number reduction
%K chromosomal rearrangements
%K chromosome banding
%K catfishes.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S1679-62252005000200006&lng=en&nrm=iso&tlng=en