A New Species of Large Flying Frog (Rhacophoridae: Rhacophorus) from Lowland Forests in

We describe a new species of Rhacophorus from lowland forests in southern Vietnam. The new species is most similar to Rhacophorus kio, but differs from this and all other Rhacophorus from Southeast Asia by a combination of its large body size (males 72.3-85.5 mm; females 89.4-90.7 mm snout-vent length); green dorsum; white venter; black patch at axilla; bluish-green posterior surface of thighs with pale yellow marbling; low, single-lobed supracoloacal dermal ridge, and white sclera. In contrast to the widely distributed R. kio, the new species is known only from two fragments of disturbed, low-elevation forest approximately 30 km apart in a highly modified agricultural landscape. The continued survival of the new species is threatened by ongoing habitat loss and degradation. A significant proportion of amphibian and reptile diversity in Southeast Asia remains hidden within morphologically cryptic species groups currently treated as a single species (e.g., Bain et al., 2003; Stuart et al., 2006; Che et al., 2009). This is true even for the charismatic ''flying'' frogs in the genus Rhacophorus (Kuhl and Van Hasselt, 1822). The large ''flying'' frog Rhacophorus reinwardtii (Schlegel, 1840) was one of the first amphibians discovered in Asia (Kuhl and Van Hasselt, 1822). Described from Java, Indonesia this species was until recently thought to occur throughout Asia. In 2006, populations referred to previously as R. reinwardtii from China, Laos, Thailand, and Vietnam were described as Rhacophorus kio (Ohler and Delorme, 2006), and more recently, R.' 'reinwardtii'' from southern Thailand and Peninsular Malayasia were described as Rhacophorus norhayatii (Chan and Grismer, 2010). During recent surveys in lowland forest fragments in southern Vietnam, we discovered a large species of ''flying'' frog resembling R. kio but distinct from this species and all other congeners. Here we describe this species as new.