Scientists from Kunming Institute of Zoology (KIZ) and affiliates of Shenyang Normal University, Royal Ontario Museum, and the University of California, recently collaborated to investigate the phylogeny of the Asian spiny frog tribe Paini, Family Dicroglossidae.

The anuran tribe Paini, is known in this group only from Asia. These aquatic and semi-aquatic species live mostly in swift, boulder-strewn rivers and streams in the mountains (400–4700 m) of South and Southeast Asia. Presently, the tribe Paini includes 42 species, the majority of which (27) occur in China though the validation of some species deserve further study.

For those species occurring in Laos and Vietnam, tissues were also included from the Field Museum of Natural History, Chicago, USA, the Museum of Vertebrate Zoology, Berkeley, USA, and the Royal Ontario Museum, Toronto, Canada. Most of the identifications for these specimens took place in the field and are largely based on either female and/or juveniles and are considered to be very tentative.

The phylogenetic relationships and often the taxonomic recognition of species are controversial. In order to stabilize the classification, the authors used approximately 2100 bp of nuclear (rhodopsin, tyrosinase) and mitochondrial (12S, 16S rRNA) DNA sequence data to infer the phylogenetic relationships of these frogs.

Phylogenetic trees were reconstructed using Bayesian inference and maximum parsimony methods supported a monophyletic tribe Paini. Two distinct groups were recovered with the mtDNA alone and the total concatenated data (mtDNA + nuDNA).

The recognition of two genera, Quasipaa and Nanorana, was supported. Group I, Quasipaa, is widespread east of the Hengduan Mountain Ranges and consists of taxa from relatively low elevations in southern China, Vietnam and Laos. Group II, Nanorana, contains a mix of species occurring from high to low elevation predominantly in the Qinghai-Tibetan Plateau and Hengduan Mountain Ranges. The occurrence of frogs at high elevations appears to be a derived ecological condition.

The composition of some major species groups based on morphological characteristics strongly conflicts with the molecular analysis. Moreover, some possible cryptic species are indicated by the molecular analyses. The incorporation of genetic data from type localities helped to resolve some of the taxonomic problems, although further combined analyses of morphological data from type specimens are required.

The two nuDNA gene segments proved to be very informative for resolving higher phylogenetic relationships and more nuclear data should be explored to be more confident in the relationships.

The results of the study currently provide the most comprehensive phylogeny for the endemic Asian tribe Paini. The study encompasses a substantial portion of the range of the majority of recognized species (25 species; Table 2) and it includes intraspecific samplings for several species. Analyses of these data recover major clades in the tribe Paini, and many terminal relationships are resolved.

Che J, Hu J-s, Zhou W-w, Murphy RW, Papenfuss TJ, Chen M-y, Rao D-q, Li P-p, Zhang Y-p (2009) Phylogeny of the Asian spiny frog tribe Paini (Family Dicroglossidae) sensu Dubois Molecular Phylogenetics and Evolution Vol. 50, pp. 59–73