Spatial ecology and microhabitat selection of the nocturnal pitviper Viridovipera stejnegeri (Squamata: Viperidae) in relation to prey.

Habitat is fundamental for facilitating various life activities in animals, for instance, snakes procure essential energy for survival and reproduction by selecting ambush microhabitats. While there has been extensive research on the selection of microhabitat for feeding in terrestrial and aquatic snakes, little is known about arboreal snakes. In the present study, we analyzed the ambush microhabitat preferences of Viridovipera stejnegeri, a widely distributed Asian pitviper in China, conducted association analysis between snake microhabitat and prey microhabitat and abundance to determine the ro5le of microhabitat selection in feeding. Employing random forest analysis and habitat selection functions, we further constructed a predictive framework for assessing the probability of ambush site selection by V. stejnegeri. Our results revealed that V. stejnegeri exhibited a distinct microhabitat preference for ambush prey. Among the 13 environmental factors assessed, V. stejnegeri showed pronounced preferences towards 12 of these factors, including climatic factors, geographical factors, and vegetation factors. Furthermore, although the preferences of V. stejnegeri overlapped substantially with those of its prey across multiple habitat factors, food abundance shows no significant association with various habitat factors of V. stejnegeri, and does not have significant predictive effect on habitat selection of V. stejnegeri. Therefore, we infer that V. stejnegeri does not preferentially select microhabitats with the highest food abundance, which does not support the hypothesis that "snakes select habitats based on the spatial distribution of prey abundance." By analyzing the characteristics of vegetation, geography, and climate, we conclude that V. stejnegeri tends to choose microhabitats with better ambush conditions to increase attack success rate, thereby achieving the optimal feeding success rate at the microhabitat scale, which is in line with the predictions of optimal foraging theory. This study provides new insights into the predation ecology and habitat selection of snakes.

DNA barcoding of Chinese snakes reveals hidden diversity and conservation needs.

DNA barcoding has greatly facilitated studies of taxonomy, biodiversity, biological conservation, and ecology. Here, we establish a reliable DNA barcoding library for Chinese snakes, unveiling hidden diversity with implications for taxonomy, and provide a standardized tool for conservation management. Our comprehensive study includes 1638 cytochrome c oxidase subunit I (COI) sequences from Chinese snakes that correspond to 17 families, 65 genera, 228 named species (80.6% of named species) and 36 candidate species. A barcode gap analysis reveals gaps, where all nearest neighbour distances exceed maximum intraspecific distances, in 217 named species and all candidate species. Three species-delimitation methods (ABGD, sGMYC, and sPTP) recover 320 operational taxonomic units (OTUs), of which 192 OTUs correspond to named and candidate species. Twenty-eight other named species share OTUs, such as Azemiops feae and A. kharini, Gloydius halys, G. shedaoensis, and G. intermedius, and Bungarus multicinctus and B. candidus, representing inconsistencies most probably caused by imperfect taxonomy, recent and rapid speciation, weak taxonomic signal, introgressive hybridization, and/or inadequate phylogenetic signal. In contrast, 43 species and candidate species assign to two or more OTUs due to having large intraspecific distances. If most OTUs detected in this study reflect valid species, including the 36 candidate species, then 30% more species would exist than are currently recognized. Several OTU divergences associate with known biogeographic barriers, such as the Taiwan Strait. In addition to facilitating future studies, this reliable and relatively comprehensive reference database will play an important role in the future monitoring, conservation, and management of Chinese snakes.

Genetic diversity and sex-biased dispersal in the brown spotted pitviper (Protobothrops mucrosquamatus): Evidence from microsatellite markers.

Dispersal plays a vital role in the geographical distribution, population genetic structure, quantity dynamics, and evolution of a species. Sex-biased dispersal is common among vertebrates and many studies have documented a tendency toward male-biased dispersal in mammals and female-biased dispersal in birds. However, dispersal patterns in reptiles remain poorly understood. In this study, we explored the genetic diversity and dispersal patterns of the widely distributed Asian pitviper Protobothrops mucrosquamatus. In total, 16 polymorphic microsatellite loci were screened in 150 snakes (48 males, 44 females, 58 samples without sex information) covering most of their distribution. Microsatellite analysis revealed high genetic diversity in P. mucrosquamatus. Bayesian clustering of population assignment identified two major clusters for all populations, somewhat inconsistent with the mitochondrial DNA phylogeny of P. mucrosquamatus reported in previous research. Analyses based on 92 sex-determined and 37 samples of P. mucrosquamatus from three small sites in Sichuan, China (Mingshan, Yibin, and Zizhong) consistently suggested female-biased dispersal in P. mucrosquamatus, which is the first example of this pattern in snakes. The female-biased dispersal patterns in P. mucrosquamatus may be explained by local resource competition.

A new species of bush frog (Anura, Rhacophoridae, Raorchestes) from southern Xizang, China.

Based on molecular evidence and morphological data, we describe a new species Raorchestes yadongensis sp. nov. from Yadong County, Xizang Autonomous Region, China. The new species can be distinguished based on a combination of the following characters: (1) small body size, SVL 17.8-24.1 mm in adult males; (2) head wider than long; (3) eye diameter about three times as much as tympanum diameter; (4) tympanum distinct; (5) fingers with rudimentary webbing and narrow lateral dermal fringes; relative finger lengths I < II < IV < III; number of subarticular tubercles in fingers 1, 1, 2, 1; (6) toes with rudimentary webbing and narrow lateral dermal fringes; relative toe lengths I < II < III < V < IV; number of subarticular tubercles in toes 1, 1, 2, 3, 2; inner metatarsal tubercle distinct, outer metatarsal tubercle absent; (7) tips of fingers and toes present discs, and discs pale brown or yellow in life; (8) tibiotarsal articulation reaching the tip of snout when adpressed; (9) milky nuptial pad present on the dorsal surface of first finger; (10) dorsal surface light brown with white warts, ventral surface with irregular white patches. The new species is currently known in Yadong County, Xizang, China, but may also occur in neighboring Bhutan and India. A key to Chinese species of the genus Raorchestes is also provided.

A new species of the Achalinus rufescens complex (Xenodermidae: Achalinus) from Fujian Province, China.

A new species of the xenodermid snake genus Achalinus Peters, 1869 is described from Fujian Province, China, based on six specimens. Bayesian inference and maximum likelihood analyses based on a mitochondrial DNA fragment (CO1) indicated the new taxon is different from its congeners (pdistance ≥ 18.5%). Morphologically, the new species can be diagnosed from the other species by a combination of following characters: (1) dorsal scales 23 rows throughout, strongly keeled, the most outer rows on both sides also keeled and slightly enlarged; (2) tail relatively longer, TaL/TL ratio 0.260.29 in males, 0.210.22 in females; (3) maxillary teeth 3033; (4) length of suture between internasals significantly longer than that between prefrontals; (5) nasal divided into two sections by nasal cleft; (6) a single loreal; (7) SPO 1, seldom 2; (8) SPL 6, the fourth and fifth contacting eye; (9) IFL5, rarely 6, the first three touching the first pair of chin shields; (10) TMP 79, arranged in three rows; (11) VS 142149 in males, VS 152154 in females; (12) SC 7481 in males, SC 6365 in females, arranged in a single row; (13) cloacal entire; (14) greyish brown above, pale yellow beneath; (15) dorsum with an indistinct longitudinal vertebral stripe. The description of the new species brings the total species of Achalinus to 19.

A new species of the genus Achalinus (Squamata: Xenodermatidae) from southeastern Yunnan Province, China.

A new species of the xenodermatid snake genus Achalinus Peters, 1869 is described from Yunnan Province, Southwest China, based on a single male specimen. The new species is assigned to the genus Achalinus on the basis of absence of preocular and postocular, subcaudals arranged in single row, and results of phylogenetic analyses of mitochondrial DNA CO1 sequence data. Achalinus pingbianensis sp. nov. differs from its congeners by the combination of following morphological characters: absence of a loreal, internasals subequal to that between prefrontals and dorsal scales strongly keeled, 23 rows throughout. Currently, 13 species are in the genus Achalinus, further taxonomical and phylogenetic studies based on more extensive samples and more markers will help understand the cryptic diversity and clarify their interspecific relationships.