The Southeast Asian cascade frog, Rana livida (Blyth, 1856), has long been suspected to be a complex of species. Several different forms are described from across its vast range. The loss of type material and disparate sampling efforts are challenges. Is variability in this species due to geographic variation or to the presence of multiple species? We use concordant evidence from morphology, morphometrics, cellular DNA content, and allozyme electrophoresis to investigate diversity in R. livida from Vietnam. Three distinct species are recognized on the basis of morphology, as are four other suspect groups (morphotypes). Discriminant function analyses of morphometric data detect patterns of morphological variation among all seven groups. Pairwise comparison of cellular DNA content using t-tests shows significant differences among sympatric morphotypes, suggesting they represent distinct species. This hypothesis is supported by an analysis of 14 allozymic loci, in which fixed allelic differences are found among specimens in sympatry and allopatry. Examination of available type material of four junior synonyms of R. livida results in their recognition as species. One of these species, R. chloronota, is a wide-ranging species erroneously referred to as R. livida. Seven species occur in Vietnam.
We describe six new cryptic species belonging to the Rana chloronota complex, redescribe R. chloronota, R. livida, R. sinica, and R. graminea, and give comments on R. leporipes. Three of these new species (R. bacboensis, new species, R. hmongorum, new species, and R. daorum, new species) occur in montane forests in northern Vietnam, and two (R. banaorum, new species and R. morafkai, new species) are known only from the Tay Nguyen Plateau of Vietnam's Central Highlands. One species, R. megatympanum, new species, occurs in portions of both northern Vietnam and the Central Highlands. An identification key for the Rana chloronota complex from Vietnam is provided. The finding of six cryptic species within a small portion of the geographic region of R. chloronota suggests that many more cascade ranids await discovery. This documentation has serious implications for conservation; each of the new species occurs in sympatry with at least one other member of the complex. Consequently, far more species are being affected by habitat loss than was previously thought.