| The chromosomes of specimens from four Hoplias malabaricus populations from headwaters of adjacent river basins at Ponta Grossa, southern Brazil, were investigated using differential staining techniques (C-banding, AgNO3 and CMA3) and fluorescent in situ hybridization (FISH) with an 18S rDNA probe. The diploid chromosome number in representatives of all four populations was invariably 2n = 42, with karyotypes composed of 12 pairs of metacentrics and 9 pairs of submetacentrics, without heteromorphic sex chromosomes. This kind of karyotype represents cytotype A in regard to cytotypes identified previously in H. malabaricus, exhibiting however, at the same time, some differences in the distribution of constitutive heterochromatin segments and in the locations... |
