Phylogenetic Relationships among Chinese Rice Frogs within the Fejervarya limnocharis Species Complex (Amphibia: Dicroglossidae)

Abstract

We present a molecular assessment of the widely-distributed rice frog (Fejervar ya limnocharis) which provides many new samples tha t add to knowledge of their phylogeography within China and considers genetic support for five Chinese species within this complex. Two mtDNA fragments from 270 individuals and eight nuclear DNA loci (105 individuals) were sequenced from specimens sampled from across China. Data from nine specimens from China, Indonesia and Japan were also retrieved from previous studies. MtDNA was informative a bout population divergence within China and indicated one major clade (with four subclades) from South China and the Zhoushan Archipelago, Zhejiang, China, and a second major clade (with eight subclades) from other parts of China. Recent demographic expansions (less than 50ka ago) were detected within three of these 12 subclades, potentially associated with lowered sea-levels after marine transgressions. Notably, most frogs from the previously unstudied Zhoushan Archipelago (eastern China) were found to be closely related to Japanese populations. BPP and STACEY species delimitation analyses of the multilocus data favoured five candidate species within the complex. Previous work had described Fe jervar ya multistriata and F. kawamurai from the Chinese mainland although here we detected considerable genetic divergence within the latter and found that this may be indicative of two species. One of these corresponds to the Zhoushan Archipelago, Zhejiang, China and Japan, and the other from most parts of Chinese mainland. This study provides a large multilocus dataset that contributes to the systematics of this species complex