Abstract
The C-banded karyotype of Rana ishikawae, endemic to two of the Ryukyu Islands, Okinawa-jima and Amami-oshima, was analyzed. The karyotypes (2n=26) of the Okinawa and the Amami populations were almost identical when analyzed by the conventional Giemsa stain and there was no significant difference between each corresponding chromosome pair. However, a minor, but significant difference was detected in the presence of a specific C-band on the long arm of No. 9 chromosomes of the Okinawa population. The Amami population consistently lacked this band. The presence of an inter-island variation of Cbanded karyotypes suggests that the genotypical divergence has occurred during the geographic isolation in the geologic age between the population from Amami and Okinawa.
