Karyological analysis of Indian toad, Bufo stomaticus Lutken, 1862 from Haryana (India)

Abstract

The purpose of the present study was to investigate the karyotype of Indian toad, Bufo stomaticus as accurate as possible using air drying technique and conventional Giemsa staining. Karyotype of Bufo stomaticus Lutken, 1862 (Bufonidae) was investigated by examining metaphase chromosomes in both sexes. Spleen and testis tissue were used for karyotype analysis from 6 males and 4 female specimens. After taking the tissue in the presence of 0.1% colchicine for 12 hours in normal saline, the metaphase spreads were performed on microscopic glass slides and then air dried. Conventional Giemsa staining was applied to stain the chromosomes. The results indicated that B. stomaticus has 2n = 22 chromosomes, consisting of all metacentric chromosomes. These chromosomes were arranged in two groups: A and B. Group A consisted of 6 pairs of large chromosomes and group B 5 pairs of small chromosomes. Aneuploidy was also reported in a female individual. Secondary constriction was observed on 7th chromosome pair. The female somatic karyotype has been found to resemble in all respects to the one observed in male except for the 4th and 11th pair of chromosomes. The total haploid mean length was calculated to be 105.671 μm in male and 118.372 μm in case of female. Centromeric index, arm ratio and fundamental number (NF) was also determined.