A new caruncle-bearing Limnonectes (Anura: Dicroglossidae) from northeastern Thailand

A new species of the dicroglossid frog genus Limnonectes is described from Ubon Ratchathani Province, northeastern Thailand. Limnonectes lauhachindai sp. nov. differs from its congeners by having males with a low-profiled, U-shaped caruncle with free posterior margin that completely occupies, but does not extend beyond, the interobital region. The new species is most closely related to L. gyldenstolpei and L. dabanus. Its description brings the total number of caruncle-bearing species of Limnonectes to five.

A new Philautus (Anura: Rhacophoridae) from northern Laos allied to P. abditus Inger, Orlov & Darevsky, 1999

The small rhacophorid frog Philautus abditus is geographically restricted to central Vietnam and adjacent Cambodia. Our fieldwork in northern Laos resulted in the discovery of a Philautus species that very closely resembles P. abditus, but is at least 330 km from the nearest known locality of that species. The Laos population differs from P. abditus in mitochondrial DNA and coloration, and is described here as a new species. Philautus nianeae sp. nov. is distinguished from its congeners by having the combination of a hidden tympanum; no nuptial pads; smooth skin; large black spots on the hidden surfaces of the hind limbs; light venter with dark spotting; and a bronze iris. A second species of Philautus from northern Laos, P. petilus, is transferred on the basis of morphology to the genus Theloderma. 

Predicting environmental suitability for a rare and threatened species (Lao newt, Laotriton laoensis) using validated species distribution models

The Lao newt (Laotriton laoensis) is a recently described species currently known only from northern Laos. Little is known about the species, but it is threatened as a result of overharvesting. We integrated field survey results with climate and altitude data to predict the geographic distribution of this species using the niche modeling program Maxent, and we validated these predictions by using interviews with local residents to confirm model predictions of presence and absence. The results of the validated Maxent models were then used to characterize the environmental conditions of areas predicted suitable for L. laoensis. Finally, we overlaid the resulting model with a map of current national protected areas in Laos to determine whether or not any land predicted to be suitable for this species is coincident with a national protected area. We found that both area under the curve (AUC) values and interview data provided strong support for the predictive power of these models, and we suggest that interview data could be used more widely in species distribution niche modeling. Our results further indicated that this species is mostly likely geographically restricted to high altitude regions (i.e., over 1,000 m elevation) in northern Laos and that only a minute fraction of suitable habitat is currently protected. This work thus emphasizes that increased protection efforts, including listing this species as endangered and the establishment of protected areas in the region predicted to be suitable for L. laoensis, are urgently needed.

Inner ear morphological correlates of ultrasonic hearing in frogs

Three species of anuran amphibians (Odorrana tormota, Odorrana livida and Huia cavitympanum) have recently been found to detect ultrasounds. We employed immunohistochemistry and confocal microscopy to examine several morphometrics of the inner ear of these ultrasonically sensitive species. We compared morphological data collected from the ultrasound-detecting species with data from Rana pipiens, a frog with a typical anuran upper cut-off frequency of ∼3 kHz. In addition, we examined the ears of two species of Lao torrent frogs, Odorrana chloronota and Amolops daorum, that live in an acoustic environment approximating those of ultrasonically sensitive frogs. Our results suggest that the three ultrasound-detecting species have converged on small-scale functional modifications of the basilar papilla (BP), the high-frequency hearing organ in the frog inner ear. These modifications include: 1. reduced BP chamber volume, 2. reduced tectorial membrane mass, 3. reduced hair bundle length, and 4. reduced hair cell soma length. While none of these factors on its own could account for the US sensitivity of the inner ears of these species, the combination of these factors appears to extend their hearing bandwidth, and facilitate high-frequency/ultrasound detection. These modifications are also seen in the ears of O. chloronota, suggesting that this species is a candidate for high-frequency hearing sensitivity. These data form the foundation for future functional work probing the physiological bases of ultrasound detection by a non-mammalian ear.

Is chytridiomycosis an emerging infectious disease in Asia?

The disease chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has caused dramatic amphibian population declines and extinctions in Australia, Central and North America, and Europe. Bd is associated with >200 species extinctions of amphibians, but not all species that become infected are susceptible to the disease. Specifically, Bd has rapidly emerged in some areas of the world, such as in Australia, USA, and throughout Central and South America, causing population and species collapse. The mechanism behind the rapid global emergence of the disease is poorly understood, in part due to an incomplete picture of the global distribution of Bd. At present, there is a considerable amount of geographic bias in survey effort for Bd, with Asia being the most neglected continent. To date, Bd surveys have been published for few Asian countries, and infected amphibians have been reported only from Indonesia, South Korea, China and Japan. Thus far, there have been no substantiated reports of enigmatic or suspected disease-caused population declines of the kind that has been attributed to Bd in other areas. In order to gain a more detailed picture of the distribution of Bd in Asia, we undertook a widespread, opportunistic survey of over 3,000 amphibians for Bd throughout Asia and adjoining Papua New Guinea. Survey sites spanned 15 countries, approximately 36° latitude, 111° longitude, and over 2000 m in elevation. Bd prevalence was very low throughout our survey area (2.35% overall) and infected animals were not clumped as would be expected in epizootic events. This suggests that Bd is either newly emerging in Asia, endemic at low prevalence, or that some other ecological factor is preventing Bd from fully invading Asian amphibians. The current observed pattern in Asia differs from that in many other parts of the world.

High prevalence of the amphibian chytrid pathogen in Gabon

Amphibian chytridiomycosis is an infectious disease caused by the fungus Batrachochytrium dendrobatidis (Bd) that is implicated in the worldwide decline and extinction of amphibians. Africa has been proposed as a potential source for the global expansion of Bd, yet the distribution of Bd across the continent remains largely unexplored. Using quantitative polymerase chain reaction (qPCR), we screened for the presence of Bd in 166 adult anurans from two national parks in Gabon (Monts de Cristal and Ivindo). Bd was detected in 20 of the 42 species and was present at all three sites surveyed (two in Monts de Cristal, and one in Ivindo) with high prevalence (19.6%-36.0%). Both national parks were Bd-positive at all elevations and across habitat types, though no dead or dying frogs were encountered. To our knowledge, this study presents the first evidence of Bd in Gabon and the first record of infection for 19 of the 20 species that were Bd-positive. Documenting the distribution and virulence of Bd across Africa will be essential for understanding the dynamics of amphibian chytridiomycosis across the globe.

Introduced delicacy or native species? A natural origin of Bermudian terrapins supported by fossil and genetic data

Humans have greatly altered the natural distribution of species, making it difficult to distinguish between natural and introduced populations. This is a problem for conservation efforts because native or introduced status can determine whether a species is afforded protection or persecuted as an invasive pest. Holocene colonization events are especially difficult to discern, particularly when the species in question is a naturally good disperser and widely transported by people. In this study, we test the origin of such a species, the diamondback terrapin (Malaclemys terrapin), on Bermuda using a combination of palaeontologic (fossil, radiometric and palaeoenvironmental) and genetic data. These lines of evidence support the hypothesis that terrapins are relatively recent (between 3000 and 400 years ago) natural colonizers of Bermuda. The tiny population of Bermudian terrapins represents the second naturally occurring non-marine reptile that still survives on one of the most densely populated and heavily developed oceanic islands in the world. We recommend that they should be given protection as a native species.

Toad poisoning in Laos

We describe two patients who developed severe illness after eating the skin and eggs of a toad, probably Bufo melanostictus Schneider, in southeastern Laos. One boy died, and one developed a digoxin toxicity-like syndrome with bradycardia and heart failure but survived. A telephone survey of 16 Lao provincial hospitals suggested that toad poisoning occurs in at least six provinces. That 93% of villagers in three villages in southeastern Laos were aware that toads are poisonous but that 51% had encountered patients with toad toxicity suggests that the potential gravity is not appreciated. These data indicate that toad poisoning may be underestimated and that education on the seriousness of toad toxins could be a useful public health measure.

High level of cryptic species diversity revealed by sympatric lineages of Southeast Asian forest frogs

Amphibians tend to exhibit conservative morphological evolution, and the application of molecular and bioacoustic tools in systematic studies have been effective at revealing morphologically 'cryptic' species within taxa that were previously considered to be a single species. We report molecular genetic findings on two forest-dwelling ranid frogs from localities across Southeast Asia, and show that sympatric evolutionary lineages of morphologically cryptic frogs are a common pattern. These findings imply that species diversity of Southeast Asian frogs remains significantly underestimated, and taken in concert with other molecular investigations, suggest there may not be any geographically widespread, forest-dwelling frog species in the region. Accurate assessments of diversity and distributions are needed to mitigate extinctions of evolutionary lineages in these threatened vertebrates.

Evolutionary distinctiveness of the extinct Yunnan box turtle (Cuora yunnanensis) revealed by DNA from an old museum specimen

Cuora yunnanensis is an extinct turtle known from 12 specimens collected from Yunnan, China, before 1908. We used ancient DNA methods to sequence 1723 base pairs of mitochondrial DNA from a museum specimen of C. yunnanensis. Unlike some rare 'species' recently described from the pet trade, C. yunnanensis represents a lineage that is distinct from other known turtles. Besides C. yunnanensis, two other valid species (C. mccordi, C. zhoui) are unknown in the wild but are supposedly from Yunnan. Intensive field surveys for surviving wild populations of these critically endangered species are urgently needed.

Repeated evolution of limblessness and digging heads in worm lizards revealed by DNA from old bones

The evolutionary relationships of the burrowing amphisbaenians ('worm lizards') have long been controversial for several reasons: the rarity of museum specimens available for study, highly derived morphological conditions that can confound comparative studies and difficulty in obtaining tissues for molecular phylogenetic studies because of their secretive habits in the wild. We present a phylogenetic analysis of two nuclear genes obtained from both fresh tissues and museum specimens of worm lizards. We achieved sufficient taxonomic sampling for analysis by extracting DNA from museum specimens using a modified forensics protocol. Results show the limbless Rhineuridae to be the most basal lineage, whereas the limbed Bipedidae occupy a more derived position as the sister-taxon to a Trogonophidae-Amphisbaenidae clade. This pattern of relationships indicates widespread morphological convergence within the group, including three independent incidences of limb loss. Convergence in skull shape and scalation is also prevalent. Mosaic evolution in the skull versus postcranial skeleton parallels that seen in snake evolution.

Molecular phylogeny of the critically endangered Indochinese box turtle (Cuora galbinifrons)

The Indochinese box turtle Cuora galbinifrons is a polytypic, critically endangered species from Vietnam, Laos, and Hainan Island, China. We analyze up to 1790bp of mitochondrial DNA under maximum parsimony and maximum likelihood criteria to test if the five historically recognized subspecies represent evolutionary lineages, and to elucidate the relationship of C. galbinifrons to other Cuora. C. galbinifrons is composed of three major mitochondrial DNA clades corresponding to the three subspecies galbinifrons, bourreti, and picturata. These three lineages are also morphologically diagnosable, and consequently we recommend elevating each to full species. Cuora galbinifrons hainanensis nests within the galbinifrons clade, and we retain it as a synonym of galbinifrons, as supported by morphology. Cuora "serrata" is known to be a hybrid of male Cuora mouhotii and female C. galbinifrons, and our findings show that C. "serrata" originates from both female galbinifrons and bourreti. Little or no mitochondrial DNA variation was found among the morphologically distinct species Cuora aurocapitata, Cuora pani, and Cuora trifasciata, for which hypotheses are proposed. Recognizing galbinifrons, bourreti, and picturata as separate species has consequences for ongoing ex situ captive breeding programs and prioritization of in situ conservation activities, particularly in Vietnam.

Status of crocodiles in the U Minh Thuong Nature Reserve, southern Vietnam

Both species of native crocodile, Siamese Crocodile Crocodylus siamensis and Estuarine Crocodile C. porosus, are seriously threatened in the wild in Vietnam. The swamp forest of the U Minh region in southern Vietnam was recently suggested to harbor the last remaining wild Estuarine Crocodiles in the country. We investigated the status of crocodiles in the U Minh Thuong Nature Reserve by conducting field surveys and interviewing local people. Field surveys found no signs of living wild crocodiles, and interview results strongly suggested that wild crocodiles have not occurred at U Minh Thuong Nature Reserve for perhaps as long as 30 years.