Biosystematic study of Bufotes variabilis (Pallas, 1769) populations from East and North east of Khuzestan province based on morphometric and karyotype data

Variable toad (Bufotes variabilis) is a member of   the Bufotes viridis complex in Bufonidae family. Although this species broadly spreads in the western part of Iran, few studies have been carried out on different populations of this species in Iran, especially in Khuzestan province. Totally 59 specimens were collected from Behbahan, Masjed Soleyman and Dehdez from June 2016 to September 2017.  Analysis of variance (Anova) confirmed the separation of populations in 11 characters. The results of t-test showed no sexual dimorphism in the studied populations. The results of the discriminant analysis showed that both functions are significant.  Scatter plot of canonical functions shows that according to the first function, the specimens of Behbahan are partially separated from specimens of two other regions and according to the second function, specimens of the Masjed Soleyman are clearly separated from specimens of two other regions. Overall, 89.8% of the toads were placed in their expected groups. Karyological studies demonstrate that all samples are diploid and have 2n=22. These chromosomes are classified into two groups. The first group consists of 6 pairs of large chromosomes and the second group contains 5 pairs of small chromosomes.  In all samples of the three mentioned areas, 8 pairs of chromosomes are metacentric and 3 pairs of chromosomes are sub metacentric. Such karyotype pattern has been reported in many species of the genus Bufotes.