Karyological Studies on 5 Anuran Species (Rhacophoridae, Microhylidae) from the Western Ghats, Southwest India

Abstract

Summary Karyotypes of 5 species of Indian frogs belonging to 2 families Rhacophoridae (Polypedates maculatus, Rhacophorus malabaricus, and Pseudophilautus wynaadensis) and Microhylidae (Ramanella montana and Microhyla ornata) were described. All of the 5 species had 2nϭ26 bi-armed chromosomes with 5 large and 8 small pairs. In Rhacophorus malabaricus, 3 large chromosome pairs (nos. 2-4) possessed telomeric C-positive bands on the long arm, whereas C-positive bands were confined to the centromeric region of the chromosomes in the other 4 species. None of the species had identifiable heteromorphic sex chromosomes. Based on karyometric data and C-banding, the karyotype of each species was characterized and was compared with those of the related species. It became evident that the Indian species of the genus Microhyla differ karyologically from the congeners in southeastern Asia.Key words Karyotype, C-banding, Rhacophoridae, Microhylidae, India.In the past 6 decades, 24 species of Indian anurans were studied for their cytogenetic attributes. Of these, 3 species belong to Bufonidae (Asana and Mahabale 1941, Natarajan 1958b, Manna and Bhunya 1966, Chatterjee and Barik 1970, Singh et al. 1970, Mittal and Sawhney 1971, Singh 1974, 9 to Dicroglossidae (Natarajan 1957b, 1958a, Singh et al. 1970, Mittal and Sawhney 1971, Singh 1974, Yadav 1974, Yadav and Pillai 1975, 1976, Chakrabarti et al. 1983, Joshy et al. 1999, Joshy and Kuramoto 2008, 1 to Nyctibatrachidae (Joshy et al. 1999), 1 to Ranixalidae (Joshy et al. 1999), 3 to Ranidae (Joshy et al. 1999, 2006), 3 to Rhacophoridae (Natarajan 1957a, Singh et al. 1970, Singh 1974, Rai and Dey 1991, and 4 to Microhylidae (Bai 1956, Chakrabarti 1979, Olmo and Morescalchi 1978. Most of the previous studies, however, lacked numerical data on size and shape of chromosomes, and this makes karyotype comparisons between taxa very difficult or even impossible. In the present study, we describe karyotypes of 3 species of Rhacophoridae and 2 species of Microhylidae from the Western Ghats. Of the 5 species examined, the karyotype of Polypedates maculatus was previously reported by Natarajan (1957a), Singh et al. (1970) and Singh (1974) without karyometric data. The karyotypes of the other 4 species are here reported for the first time. Materials and methodsThree species belonging to Rhacophoridae, Polypedates maculatus, Rhacophorus malabaricus, and Pseudophilautus wynaadensis, were collected from Madikeri (altitude ca. 900 m) of Kodagu District, Karnataka, and 2 species belonging to Microhylidae, Ramanella montana and Microhyla ornata, were collected from Sagar (altitude ca. 560 m) of Shimoga District, Karnataka. Both

Cytogenetic Study of Three Microhylid Species (Anura, Microhylidae) from Thailand

“…M. fissipes, M. pulchra and M. heymosi herein showed the same diploid number and fundamental number having 2n=24 (NF= 48). These results are in concordance with previous cytogenetics data (Zheng and Fuwu 1995, Qian and Zhu 2000, Supaprom and Baimai 2002, Joshy and Kuramoto 2011, with the exception of M. butleri which had 2n=22 (NF= 44) (Baorong et al 1990, Zheng and Fuwu 1995, Supaprom and Baimai 2002 and M. rubra which had increased 2n=26 chromosomes (NF=52) ( Kasturi Bai 1956), the latter of which is similar to the Phyllomedusa species exhibiting a conservative chromosome number of 2n=26 (Haddad et al 1994, Morando and Hernando 1997, Kasahara et al 2007, Bruschi et al 2012.…”

“…The use of additional NOR-banding techniques also showed some differences in their karyotypes, supporting the idea that one of them (M. heymonsi) are species-specific. Moreover, there were other Microhyla species reported; M. ornata showed the NORs on chromosome pair 11 (Joshy and Kuramoto 2011), and M. butleri had the NORs on chromosome pair 8 (Zheng and Fuwu 1995). The difference of the NOR position in homologous chromosomes at interspecific levels is not infrequent and this may be important to characterize individual species with the same karyotypes (Silva et al 2000).…”

“…Perhaps due to its body being very small, there is a lack of cytogenetics data compared with other members of the anuran family. According to the compilation of cytogenetics for this genus, the majority of the species had a diploid number of 2n=24 and had a fundamental number (NF) of 48 (Zheng and Fuwu 1995, Qian and Zhu 2000, Supaprom and Baimai 2002, Joshy and Kuramoto 2011. However, some species such as M. butleri showed the diploid number 2n=22 (NF= 44) (Baorong et al 1990, Zheng Bai (1956) Remarks: 2n=diploid chromosome number, NF=fundamental number (number of chromosome arms), m= metacentric chromosome, sm=submetacentric chromosome, a=acrocentric chromosome, chro.=chromosome and = not available.…”