Two new species of the “kuhlii” complex of the genus Limnonectes from Thailand (Anura: Dicroglossidae)

Abstract

Phylogenetic relationships inferred from sequences of the mitochondrial 12S rRNA, tRNA val , and 16S rRNA genes and nuclear POMC and RAG-1 genes revealed that fanged frogs from Thailand usually associated with Limnonectes kuhlii are monophyletic and are collectively sister to the clade containing three Chinese and Japanese species. Within the Thai clade, the northern lineage, the southern lineage, and a population originally assigned to L. megastomias show unresolved relationships with each other, but are separated by genetic distances that correspond to values found among species of the Chinese-Japanese clade. Hybridization and past gene introgression are not detected among these three lineages of fanged frogs from Thailand. Adult specimens of the northern and southern lineages are phenotypically similar to each other, but can be separated by the combination of several morphometric characters. From the genetic and morphological evidence, they are considered to represent taxonomically different species. We therefore describe the northern lineage as L. taylori sp. nov. and the southern lineage as L. jarujini sp. nov. Taxonomic identity of the Loei population of L. megastomias requires future morphological investigation. The distribution pattern of fanged frogs within Thailand is discussed and the significance of the Three Pagodas Fault Zone is noted.