A new species of Leptobrachella (Anura, Megophryidae) from Mount Pu Ta Leng, northwest Vietnam.

The Hoang Lien Range in northwest Vietnam is known to harbour five species of Leptobrachella, a specious genus of terrestrial frogs. We collected specimens of Leptobrachella from Mount Pu Ta Leng on the second highest peak in the Hoang Lien Range and use morphological and molecular data to show that this population represents a previously undescribed species which we name Leptobrachella graminicola sp. nov. after the abundance of calling males on sedge-like plants. This new species is closely related to L. bourreti but the new species is distinguished from L. bourreti and other congeneric species by a combination of the following characters: (1) a body size range of 23.124.6 mm in six adult males and 28.632.9 mm in five adult females; (2) skin on dorsum smooth, with many tubercles and lacking dermal ridges; (3) toes with rudimentary webbing and broad lateral fringes; (4) belly white with brown spots; (5) throat dark brown with light grey-brown flecks and spots; (6) a row of large white spots on the outer edge of the tarsus extending from the heel to the inner metatarsal tubercle, sometimes forming a long white stripe; and (7) a bicoloured iris. The new, high-elevation species is likely to be range-restricted and threatened by habitat loss and the activities of tourists.

Cryptic diversity of limestone karst inhabiting land snails (Cyclophorus spp.) in northern Vietnam, their evolutionary history and the description of four new species.

Limestone karsts can form terrestrial habitat islands for calcium-dependent organisms. In Vietnam, many karst habitats are threatened, while their rich biodiversity is still far from being thoroughly explored. Given that conservation of karst biota strongly relies on correct species identification, the presence of undetected cryptic species can pose severe problems. The present study focuses on cryptic diversity among karst-inhabiting land snails of the genus Cyclophorus in northern Vietnam, where specimens with a similar shell morphology have been reported from various regions. In order to examine the diversity and evolutionary history of this "widespread morphotype", we generated a Bayesian phylogeny based on DNA sequence data. Automatic Barcode Gap Discovery (ABGD) and the Bayesian implementation of the Poisson tree processes model (bPTP) contributed to species delimitation and analyses of shell shape and size aided the morphological characterisation of individual species. We found that the examined specimens of the widespread morphotype did not form a single monophyletic group in the phylogeny but clustered into several different clades. We delimited nine different species that develop the widespread morphotype and described four of them as new. Processes of convergent evolution were probably involved in the origin of the delimited species, while their generally allopatric distribution could result from interspecific competition. Our findings indicate ongoing processes of speciation and a potential case of morphological character displacement. The high degree of morphological overlap found among the species underlines the importance of DNA sequence data for species delimitation and description in the genus Cyclophorus. Given the findings of the present study and the high potential that as yet undiscovered cryptic taxa have also evolved in other groups of karst-inhabiting organisms, we argue for a systematic and efficient detection and description of Vietnam's karst biodiversity to provide a solid basis for future conservation planning.

Two new and potentially highly threatened Megophrys Horned frogs (Amphibia: Megophryidae) from Indochina's highest mountains.

Megophrys are a group of morphologically conserved, primarily forest-dependent frogs known to harbour cryptic species diversity. In this study, we examined populations of small-sized Megophrys from mid- and high elevation locations in the Hoang Lien Range, northern Vietnam. On the basis of morphological, molecular and bioacoustic data, individuals of these populations differed from all species of Megophrys known from mainland Southeast Asia north of the Isthmus of Kra and from neighbouring provinces in China. Further, the newly collected specimens formed two distinct species-level groups. We herein describe two new species, Megophrys fansipanensis sp. nov. and Megophrys hoanglienensis sp. nov. Both new species are range restricted and likely to be highly threatened by habitat degradation. These discoveries highlight the importance of the Hoang Lien Range for Vietnam's amphibian diversity.

Competition matters: Determining the drivers of land snail community assembly among limestone karst areas in northern Vietnam.

The insular limestone karsts of northern Vietnam harbor a very rich biodiversity. Many taxa are strongly associated with these environments, and individual species communities can differ considerably among karst areas. The exact processes that have shaped the biotic composition of these habitats, however, remain largely unknown. In this study, the role of two major processes for the assembly of snail communities on limestone karsts was investigated, interspecific competition and filtering of taxa due to geographical factors. Communities of operculate land snails of the genus Cyclophorus were studied using the dry and fluid-preserved specimen collections of the Natural History Museum, London. Phylogenetic distances (based on a Bayesian analysis using DNA sequence data) and shell characters (based on 200 semilandmarks) were used as proxies for ecological similarity and were analyzed to reveal patterns of overdispersion (indicating competition) or clustering (indicating filtering) in observed communities compared to random communities. Among the seven studied karst areas, a total of 15 Cyclophorus lineages were found. Unique communities were present in each area. The analyses revealed phylogenetic overdispersion in six and morphological overdispersion in four of seven karst areas. The pattern of frequent phylogenetic overdispersion indicated that competition among lineages is the major process shaping the Cyclophorus communities studied. The Coastal Area, which was phylogenetically overdispersed, showed a clear morphological clustering, which could have been caused by similar ecological adaptations among taxa in this environment. Only the community in the Cuc Phuong Area showed a pattern of phylogenetic clustering, which was partly caused by an absence of a certain, phylogenetically very distinct group in this region. Filtering due to geographical factors could have been involved here. This study shows how museum collections can be used to examine community assembly and contributes to the understanding of the processes that have shaped karst communities in Vietnam.

The Vietnamese population of Megophrys kuatunensis (Amphibia: Megophryidae) represents a new species of Asian horned frog from Vietnam and southern China.

The Asian frog genus Megophrys is a diverse group of morphologically conserved, forest-dwelling frogs. The genus harbours highly localised species diversification and new species continue to be described on a regular basis. We examined the taxonomic status of a population of Megophrys frogs from the Hoang Lien Range in northern Vietnam and southern China previously identified as M. kuatunensis (subgenus Panophrys). Preliminary phylogenetic analyses using a fragment of 16S rDNA places the species in question within the Megophrys (subgenus Panophrys) species group, a primarily Chinese radiation within the genus. On the basis of morphological, molecular and bioacoustic data, we conclude that this population does not represent M. kuatunensis, or any known species in the genus. We herein describe this species of Megophrys as new. Known only from Sa Pa District, Lao Cai Province in Vietnam and Jinping County, Yunnan Province in China, the new species is likely to be threatened by ongoing deforestation in the region. We provide an updated species description of M. kuatunensis based on type specimens, and suggest that M. kuatunensis is likely to be restricted to eastern China.