Karyotypic Variations in Three Indian Species of the Genus Rana (Anura: Ranidae) from the Western Ghats, India

抄録

The karyotype and C-banding analysis of somatic metaphase chromosomes were attempted on 3 species of Indian frogs (Rana curtipes, R. temporalis, R. malabarica) which are distributed in the Western Ghats, Southwest India. All had 2n=26 chromosomes with invariably 5 pairs of large and 8 pairs of small chromosomes. Metacentric and submetcentric chromosomes were found in the complement, the former more common than the latter. A secondary constriction with a prominent satellite in the short arm of nos. 10 and 12 chromosomes are unique only in R. curtipes. The C-positive telomeric bands were localized in the short arms of nos. 9 and 10 chromosomes of R. temporalis. Non-centric C-positive bands were observed in the distal half of the long arm of no. 10 chromosome of R. malabarica. None of the 3 species had an identifiable sex chromosome. There were variations in the centromeric position and secondary constriction of chromosome pair nos. 2, 3, 4, 5, 9, 11 and 12. These variations might have arisen due to pericentric inversions. It seems likely from the inversion studies that R. curtipes and R. temporalis are chromosomally more closely related than R. malabarica. Comparative account of karyotypes are discussed.