Cryptic Diversity Of Giant Spiny Frogs Inferred From Mitochondrial DNA Markers

Cryptic species are morphologically undetected yet genetically divergent species. It’s very difficult to distinguish in morphological and sometimes even impossible to distinguish so that cryptic species was incorrectly attributed to a single species, with the rapid development of molecular biology In recent years, biological diversity hidden within species are increasingly being discovered. There are many challenges on biodiversity estimation from the prevalence of cryptic species. Due to the weak of migration and strong philopatric, amphibians usually have a strong genetic differentiation and might be storehouses of tremendous cryptic diversity. The distribution of Giant spiny frogs (Paa spinosa) in China is the most extensive in Paa. Early genetic structure based on short fragment Cyt b of spinosa quite different, suggesting that there may be hidden to cryptic species. To test this hypothesis, this study intends to adopt multi-gene combination of methods to explore the phylogeographic structure of P. spinosa. We did research on genetic diversity and population genetic structure of the giant spiny frog population from different geographies by using mitochondrial DNA as genetic markers. The major results are as follows:Determination of this study in mainland China10geographic populations of170P. spinosa samples,9Paa jiulongensis samples,6Paa boulengeri,8Paa verrucospinosa,13Paa exilispinosa samples and23Paa shini samples (total number of samples to229) of the mitochondrial16S rRNA,12S rRNA gene sequence, its gene sequence length1338bp, found a total of118variable sites, defined38(16S rRNA) and65(12S rRNA) haplotypes. Based on method of the neighbor-joining (NJ), maximum parsimony (MP), maximum likelihood (ML) and minimum evolution (Maximum evolution, ME), constructed haplotype phylogenetic tree structure, the results show that:the P. spinosa populations are divided into two monophyletic from10geographic populations, the Clade AI and Clade All. Clade AI including Lishui, Jinhua, Huangshan, Wuyishan population, corresponding to the eastern area of P. spinosa in distribution; monophyletic All including geographic populations of Jinggangshan, pingjiang, Yangshan, Lushan, Yongfu, Longsheng, corresponding to the central of geographical distribution of P. spinosa. Calculation the genetic distance of P. spinosa based on the phylogenetic tree, The results of16S rRNA gene showed that the average genetic distance is2.863percent between monophyletic AI and P. exilispinosa, the average genetic distance is2.013percent between monophyletic All and P. exilispinosa, the average genetic distance is2.675percent between monophyletic AI and All, greater than the genetic distance between monophyletic All and P. exilispinosa, reach the level above the species. the results of12S rRNA gene keep consistent with16S rRNA gene, The results of12S rRNA gene showed that the average genetic distance is2.845percent between monophyletic AI and P. exilispinosa, the average genetic distance is2.392percent between monophyletic All and P. exilispinosa, the average genetic distance is2.738percent between monophyletic AI and All, greater than the genetic distance between monophyletic All and P. exilispinosa, reach the level above the species. Combined with previous research, there are two cryptic species at least in p. spinosa in widely distributed in southern China. In the future, further study of two monophyletic contact with molecular biology and morphology, behavior and so on, will be beneficial to clarify the mechanism of formation of cryptic species in p. spinosa.