Castillo-Urbina, E., M. Vences, M. Dezetter, F. Glaw, C. Burgos, L. Aliaga, G. Torres-Ccasani, S. F. Hope, A. Mendoza & J. Köhler

New insights into the diversity of Oreobates frogs (Anura: Craugastoridae): description of a new species from the Peruvian Yungas and comments on O. quixensis and O. saxatilis. pp. 423-441 plus Supplementary material.

Abstract. We investigate the taxonomic status of specimens of the pristimantine frog genus Oreobates recently collected in montane rainforest within the Biocorredor Bosques de Vaquero ‘Shunku Sacha’, San Martín Department, Peru. A phylogenetic analysis of these frogs based on DNA sequences of the mitochondrial 16S rRNA gene revealed a lineage closely related to Oreobates colanensis. However, that lineage is divergent from O. colanensis by 10.1% uncorrected pairwise distance in the 16S gene fragment, and from other species of Oreobates included in the analysis by more than 13.8%. Moreover, specimens in that lineage are distinguished from those of all recognized nominal species of Oreobates by a unique combination of morphological characters, including skin on the dorsum granular, absence of dorsolateral folds, presence of nuptial pads in males, absence of vocal slits and vocal sacs in males, and the absence of basal webbing on toes. Consequently, we describe this lineage as a new species, Oreobates shunkusacha sp. n. We also report on additional vouchers of Oreobates collected in the lowland Amazonian rainforest of Panguana, Huánuco Department, central Peru. Based on morphology, mitochondrial (16S) and nuclear genes (POMC, RAG-1), we demonstrate that Oreobates specimens from this locality belong to two distinct species-level lineages, referred to as O. quixensis and O. saxatilis, thus providing conclusive evidence for sympatric occurrence of these two nominal taxa that were previously considered to have parapatric ranges. Furthermore, we provide and discuss data suggesting that a misidentification of previously sequenced specimens, including the paratopotype of O. saxatilis, is likely responsible for the paraphyly of O. quixensis and O. saxatilis in previously published mitochondrial trees. Upon correction of these putative misidentifications, the morphologically diagnosable species O. quixensis and O. saxatilis are monophyletic and occur in close sympatry at certain localities in the upper Amazon basin.

Key words. Amphibia, Pristimantinae, molecular genetics, morphology, Peru, sympatry, systematics, taxonomy, misidentification, conservation.