Systematic reassessments of fanged frogs from China and adjacent regions (Anura: Dicroglossidae)

Systematic relationships of fanged frogs usually associated with Limnonectes kuhlii are assessed using 15 samples from Japan, Chinese Mainland and Taiwan, Vietnam, Laos, Thailand, Malaysia (Borneo), and Indonesia. Phylogenetic relationship inferred from the mitochondrial 12S rRNA, tRNA(val), and 16S rRNA gene sequences revealed that fanged frogs sampled are not monophyletic with the topotypic L. kuhlii from Java. Samples from Yunnan of southern China (L. bannaensis), northern Laos and central Vietnam, and those from Jiangxi of eastern China (L. fujianensis), Taiwan and Japan (L. namiyei), respectively, form monophyletic groups, and are collectively sister to the Thai sample (L. megastomias). All these samples, L. fragilis from Hainan of southern China, and a group of Bornean samples show unresolved relationships with Javanese L. kuhlii. From the resultant phylogeny and genetic distances found among samples, L. "kuhlii" from Taiwan and L. fujianensis, and L. "kuhlii" from northern Laos and central Vietnam and L. bannaensis, respectively, are surmised to be conspecific. These fanged frogs are morphologically similar to, but phylogenetically distant from, L. kuhlii sensu stricto. Limnonectes namiyei, L. fujianensis, and L. bannaensis are considered to have a common ancestor whose chromosome number was 2n=22, unlike L. fragilis, L. kuhlii and many other frogs with 2n=26 chromosomes.