Remarkable genetic homogeneity in unstriped, long-tailed Ichthyophis along 1500 km of the Western Ghats, India |
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Authors: | D J Gower M Dharne G Bhatta V Giri R Vyas V Govindappa O V Oommen J George Y Shouche & M Wilkinson |
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Institution: | Department of Zoology, The Natural History Museum, London, UK; National Centre for Cell Science, Pune University Campus, Ganeshkhind, Pune, India; Department of Zoology, M.G.M. College, Udupi, Karnataka, India; Bombay Natural History Society, Hornbill House, Mumbai, India; Sayaji Baug Zoo, Vadodara, Gujarat, India; Department of Zoology, Bangalore University, Bangalore, Karnataka, India; Department of Zoology, University of Kerala, Kariavattom, Thiruvananthapuram, Kerala, India |
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Abstract: | The mountainous Western Ghats are part of a biodiversity hotspot and extend for about 1600 km, lying close and subparallel to the west coast of peninsular India. The region is a centre of diversity for amphibians, and recent preliminary work on some components of both caecilian (Gymnophiona) and frog (Anura) fauna is indicative of a high degree of local endemism. We investigated diversity in mitochondrial rRNA 12S and 16S sequences for long-tailed, unstriped Ichthyophis (Amphibia: Gymnophiona: Ichthyophiidae) that potentially represent four taxonomically confused and poorly known endemic caecilian species. Data were analysed for18 individuals from along c . 1500 km of the Western Ghats region. Genetic diversity is remarkably low, with a maximum uncorrected p -distance of 0.5%. These DNA sequences and new morphological data do not allow us to reject the null hypothesis that the sample comprises only a single, widely distributed, highly interconnected species. The phylogenetic signal among the data is extremely low. However, population genetic analyses reveal that the Palghat Gap, a c . 30 km discontinuity in the Western Ghats considered to be significant in the biogeography of other organisms occurring in this region, corresponds to a significant subdivision of long-tailed, unstriped Ichthyophis into two groups. |
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Keywords: | caecilians Palghat Gap phylogeny population genetics taxonomy |
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