| extraordinary chromosomal polymorphism with 28 different karyotypes in the neotropical species akodon cursor (muridae, sigmodontinae), one of the smallest diploid number in rodents (2n = 16, 15 and 14). | all available published cytogenetic data show the presence of 28 different karyotypes in 311 specimens of a. cursor as an exceptional example of high karyotype variability in a single species. our present sample of 116 animals collected in the rain forest of the atlantic coast of the states of são paulo and bahia, brazil, show 25 karyotype constitutions. the diploid number (2n) ranged from 16 to 14, and the number of autosomal arms (nf) from 26 to 18, because of centric fusion and pericentric in ... | 1998 | 10319722 |