New insights on the systematics and reproductive behaviour in tree frogs of the genus Feihyla, with description of a new related genus from Asia (Anura, Rhacophoridae)

The taxonomy of the Asian tree frog genus Feihyla has been in a state of flux ever since its proposal in 2006. Allocation of species to Feihyla remains confusing, particularly with respect to the closely related genus Chirixalus (formerly Chiromantis sensu lato). At the same time, several Chirixalus species are known only from cursory descriptions and remain poorly studied. In this study, we review the systematics of the genus Feihyla and clarify the generic placement of its members along with all other species currently assigned to Chirixalus. Based on integrative evidence gathered from new collections, examination of types and original descriptions, morphological comparisons, phylogenetic relationships inferred from a multi-gene (three mitochondrial + two nuclear) 1,937 bp dataset, as well as reproductive modes including egg-laying, nesting behaviour, and clutch morphology, our results show that the six species formerly attributed to Feihyla represent three morphologically and phylogenetically distinct groups: (1) the type species of the genus, F. palpebralis, along with F. fuhua constitute the Feihyla palpebralis group or Feihyla sensu stricto; (2) F. inexpectata and F. kajau represent the Feihyla vittiger group and are closely related to the Feihyla palpebralis group; (3) ‘F. hansenae’ and ‘F. vittata’ constitute another distinct and reciprocally monophyletic lineage, more closely related to Chirixalus + Chiromantis. In light of long-standing taxonomic confusions and unresolved phylogenetic relationships, we propose recognition of a new genus to accommodate ‘F. hansenae’ and ‘F. vittata’ in order to stabilise the classification of several Asian rhacophorid species that have been frequently confused and transferred within the Chirixalus–Chiromantis–Feihyla complex. Based on integrative evidence, eight species previously attributed to the genus Chirixalus or Feihyla are formally transferred to Rohanixalus gen. nov., two Chirixalus members are allocated to Feihyla, and one synonymised with Rhacophorus bipunctatus. In addition, we report the first member of the tree frog family Rhacophoridae from the Andaman Islands of India—Rohanixalus vittatus, along with description of its male advertisement call, reproductive behaviour including parental care by the female, and larval morphology. Extended distributions are also provided for Rohanixalus species across Northeast India. The study further reveals the presence of potentially undescribed diversity in the new genus. Altogether, the revised classification and novel insights presented herein will facilitate a better working taxonomy for four phylogenetically distinct but morphologically related groups of Old World tree frogs.