ИСТИНА

Amphibian populations are dramatically declining worldwide, while their inventory is far from being achieved. In Taiwan, decline of amphibian species and populations is caused mainly by habitat loss, overexploitation and climate change. DNA barcoding is a proven tool for the rapid and unambiguous identification of species, which is especially essential for amphibians, because many species are now becoming critically endangered. In the present study we have constructed a comprehensive COI barcode database, covering all the currently recorded species of amphibians in Taiwan and adjacent islands. This database will provide a basis and a standardized tool for species identification in monitoring and management programs on Taiwanese amphibians (5 urodeles and 35 anurans). A total of 383 individuals from 31 native and 4 introduced species of frogs and from 5 native species of salamanders (genus Hynobius) were used to generate barcode sequences using partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene. We compare performance of several sets of universal COI-barcoding primers suggested for amphibian barcoding. We also evaluate the use of phylogenetic species concept (PSC)-based approaches for species delimitation from a single gene using COI region as a barcode marker (bGMYC, Bayesian General Mixed Yule Coalescent and ABGD, Automatic Barcode Gap Discovery). Although we failed to find a clear barcoding gap due to the high levels of intraspecific variation in COI gene found in many groups, all of the analyzed individuals from the same species were assigned correctly and clustered together. We report the COI as a useful marker for uncovering cryptic diversity and phylogeographic structure in Taiwanese amphibian species: altogether our analysis has revealed 54 major mtDNA lineages many of which show clear geographic structuring in their distribution (in most cases East Taiwan vs. West Taiwan disruption). In some cases, however, high intraspecific variation suggests the possibility of cryptic species.