Three new species of the gekkonid lizard genus Hemiphyllodactylus are described from Hainan Island, China, based on morphological comparisons and phylogenetic analyses based the ND2 gene. This brings the total number of the known species from one to four, revealing the previously underestimated diversity of Hainan’s herpetofauna. The three new species, along with Hemiphyllodactylus typus, are placed into three different clades, suggesting multiple colonization events and independent evolutionary histories of the genus on Hainan Island. The known distribution of H. typus was further expanded in this study, and its current status on this island was examined, highlighting the cryptogenic nature of the species with unclear native and introduced ranges. These findings emphasize the need for detailed molecular studies using sensitive genetic markers and extensive geographical sampling to clarify its origins.
Chemical communication is an important mode of communication in the courtship and breeding processes of amphibians. In caudates, multiple components of sexual pheromones have been identified and functionally verified. One of these pheromone systems is plethodontid modulating factor (PMF). In anurans, the pheromone called amplexin was found in nuptial pads of ranids and was considered a member of the PMF system, yet its bio-function has not been tested. In this study, we obtained 18 amplexin transcript sequences from nuptial pads of Nidirana pleuraden (Amphibia, Ranidae) by transcriptome sequencing and found that the proteins translated by these transcripts are diversified, hydrophilic, and relatively stable. We also acquired a N. pleuraden amplexin isoform with the highest expression level in the transcriptome analysis through the prokaryotic expression system. Using two different animal behavioral experimental settings, we have tested the bio-function of the recombinant PMF protein (rPMF) in N. pleuraden’s reproduction and found that the rPMF does not attract females but shortens the duration of amplexus significantly. This is the first study to verify the function of the PMF pheromone in Anura, indicating the pervasiveness of chemical communication during breeding in amphibians.
A new species of the genus Oreolalax Myers & Leviton, 1962 is described from Sichuan Province, southwest China. Molecular phylogenetic analyses based on mitochondrial gene sequences clustered the new species as an independent clade nested with O.rugosus, O.liangbeiensis, and O.major. The new species could be distinguished from its congeners by a combination of the following characters: body size moderate (39.8-52.8 mm in male); head broad; tympanum absent; interorbital region with dark triangular pattern; 1/3 toes webbed, with broad lateral fringes, belly smooth, brown yellow or medium yellow scattered variable brown spots; skin on dorsum relatively rough with fine tiny and large warts granules; middle pectoral glands are evident in males; flanks with dark-brown warts granules; upper surface of limbs with dark bars; and iris orange above and creamy-white below. The new species inhabits subtropical alpine scrub and swamp.
A new species of the genus Oreolalax Myers & Leviton, 1962 is described from Sichuan Province, southwest China. Molecular phylogenetic analyses based on mitochondrial gene sequences clustered the new species as an independent clade nested with O. rugosus, O. liangbeiensis, and O. major. The new species could be distinguished from its congeners by a combination of the following characters: body size moderate (39.8–52.8 mm in male); head broad; tympanum absent; interorbital region with dark triangular pattern; 1/3 toes webbed, with broad lateral fringes, belly smooth, brown yellow or medium yellow scattered variable brown spots; skin on dorsum relatively rough with fine tiny and large warts granules; middle pectoral glands are evident in males; flanks with dark-brown warts granules; upper surface of limbs with dark bars; and iris orange above and creamy-white below. The new species inhabits subtropical alpine scrub and swamp.
Herpetofauna have attracted considerable global attention due to their high risk of extinction. The Mountains of Southwest China are among the 36 global biodiversity hotspots due to their high biodiversity and irreplaceability, and the Shaluli Mountains are the core area of this region. However, the diversity and conservation status of herpetofauna in the Shaluli Mountains remain unclear. In this study, we updated the species richness and composition information of herpetofauna in the Shaluli Mountains based on extensive field expeditions, published literature, and museum specimens. In addition, we identified the local hotspots and key environmental factors limiting species distribution using environmental niche models (ENMs). Furthermore, we evaluated the conservation status of the key species via the Red List Index and gap analysis. Our results revealed a total of 68 herpetofauna species, representing 30 amphibians (21 genera in nine families) and 38 reptiles (19 genera in six families). The amphibian richness showed a hump-shaped pattern along the elevational gradient, while the reptile richness showed a monotonically decreasing pattern. The dry-hot river valley was identified as a local hotspot, and the key environmental factors limiting the richness of herpetofauna species differed. Moreover, the regional Red List indices for amphibians and reptiles were 0.87 and 0.8, respectively, showing that the overall threat level of this region was low. However, there are large conservation gaps in the protection of key species. Our study indicated that new protected areas should be established and the existing protected areas should be upgraded to protect herpetofauna with a large conservation gap.
A new species of the genus Liurana is morphological and molecular data. Molecular phylogenetic analysis based on the mitochondrial gene COI indicated that this new species represented an independent evolutionary lineage. In addition, the uncorrected genetic distance between the new species and its closest congener species, L. alpina, was 9.6%-9.8% for COI. The new species, Liurana namchabarwa sp. nov. Yu, Lin, Wang, Jiang and Xie, could be distinguished from its congeners by following characters: (1) relatively large body size in this genus, SVL = 21.2-23.1 mm in adult males (n = 3); long hindlimbs, with tibiotarsal articulation reaching tip of snout when adpressed.
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Pheromones play a pivotal role in chemical communication across various taxa, with protein-based pheromones being particularly significant in amphibian courtship and reproduction. In this study, we investigate the Emei music frog (Nidirana daunchina), which utilizes both acoustic and chemical signals for communication. Base on a de novo assembled genome of a male Emei music frog, we identify substantial expansion in four pheromone-related gene families associated with chemical communication. Notably, six members of the two-domain three-finger protein (2D-TFP) family, belonging to the sodefrin precursor-like factor (SPF) pheromone system, exhibited high and specific expression in the male post-axillary glands during the breeding season. Structural and evolutionary analyses confirm the presence of the SPF system across amphibians, classifiable into four distinct classes (two within urodeles and two within anurans). We propose a complete regulatory network governing SPF secretion via the hypothalamic-pituitary-testicular-breeding gland axis, and suggest testosterone synthesis as the pivotal pathway. Behavioral experiments further reveal a previously unknown female-attractant role of SPF in anurans. Overall, these findings not only highlight the underestimated diversity and function of pheromones in anurans, but also provide important insights into the evolution of protein-based pheromones in vertebrates.
栖息地丧失和退化严重威胁全球两栖类动物的生存与繁衍,栖息地保护在两栖动物保育中具有高的优先性.大凉螈(Liangshantriton taliangensis)是国内外广泛关注的横断山区特有珍稀有尾类物种.结合大凉螈 33 个分布位点和 9 个环境变量数据,本文运用最大熵(MaxEnt)模型预测了大凉螈当前潜在适宜分布区,再根据现有自然保护地(5 个国家级和9 个省级)分布进行了保护空缺分析,同时,借助比例体重指数法(SMI)衡量了 7 个种群共 218 个个体的身体状况,比较了保护区内外种群间的差异,利用归一化植被指数(NDVI)识别了保护区内植被变化,据此对四川栗子坪国家级自然保护区的保护成效进行了评估.结果表明,(1)影响大凉螈分布的最主要环境变量为NDVI(贡献值 34.33%)、最干月份降水量(贡献值 26.81%)和海拔(贡献值20.92%);(2)大凉螈适宜生境主要集中在小相岭和凉山山系,占研究区域总面积的 15.38%,现有自然保护地覆盖了大凉螈23.62%的适宜生境,仍有 3760.91km2的保护空缺;(3)栗子坪保护区内雄性个体肥满度指数显著大于保护区外个体(t-test,P= 0.006),雌性个体肥满度指数无显著差异(t-test,P=0.214),保护区内近 6 年NDVI值显著高于保护区建立前(Mann-Whitney U test,P<0.0001),均提示总体保护成效优.结合研究结果,提出了确立大凉螈为重要保护目标物种、扩大现有保护区、建立保护小区或拯救中心、建设生态廊道等保护地建设的物种恢复措施,以提升对大凉螈的保护能力.
Confused geographical structure of a population and mitonuclear discordance are shaped by a combination of rapid changes in population demographics and shifts in ecology. In this study, we generated a time-calibrated phylogeny of Scutiger boulengeri, an endemic Xizang alpine toad occurring in mountain streams on the Qinghai-Xizang (Tibet) Plateau (QTP). Based on three mitochondrial DNA (mtDNA) genes, eight clades were assigned to three deeply divergent lineages. Analysis of nuclear DNA (nuDNA) genes revealed three distinct clusters without geographic structure, indicating significantly high rates of gene flow. Coalescent theory framework analysis (approximate Bayesian computation model DIYABC and Migrate-N) suggested that divergence of the main intraspecific clusters was the result of hybridization after secondary contact in the Holocene around 0.59 million years ago (Ma). The ratio of mtDNA FST (fixation index) to nuDNA FST was 2.3, thus failing to show male-biased dispersal. Geographic cline analysis showed that a wide hybrid zone was initially established in southwestern China, without significant reproductive isolation but with strong introgression in S. boulengeri, suggesting high hybrid fitness. Furthermore, mtDNA genes exhibited isolation by distance (IBD) while nuDNA genes exhibited significant isolation by environment (IBE). Results suggested that mitonuclear discordance may have initially been caused by geographic isolation, followed by precipitation-mediated hybridization, producing a wide hybrid zone and geographic structure confusion of nuDNA genes in S. boulengeri. This study indicated that complicated historical processes may have led to specific genetic patterns, with a specific climate factor facilitating gene flow in the system.
2021 年7 月在四川省宜宾市筠连县大雪山风景区乌岭沟东北(27°53′ N,104°45′ E,海拔1380 m)采集到2 号角蟾科(Megophryidae)布角蟾属(Boulenophrys)物种标本(标本号:WG202107005 和WG202107006).通过形态学比较并基于线粒体16S rRNA 和细胞色素氧化酶亚基I(COI)基因序列构建的最大似然树显示,2 号标本是黔北角蟾(B.qianbeiensis).目前,己知黔北角蟾分布于贵州省桐梓县黄连自然保护区和贵州省宽阔水国家级自然保护区,此次在四川宜宾发现黔北角蟾确定为四川省两栖类分布新记录种.
Seasonal variation has been shown to influence symbiotic bacterial community composition and structure in amphibians. It is still unknown how the symbiotic bacterial community assembly changes during different seasons, especially for amphibians who are particularly sensitive to environmental change. We found significant differences in the composition and diversity (alpha and beta diversity) of amphibian skin and gut bacteria. Co-occurrences network analysis showed that seasonal variation reduced the microbial network complexity of amphibians from summer to autumn. The normalized stochastic ratio (NST) and phylogenetic bin-based null model analysis (iCAMP) models showed that the same result that stochastic processes was the major factor regulating the symbiotic bacterial community assembly mechanisms of amphibians. From summer to autumn, the symbiotic bacterial community assembly mechanisms declined in the contribution of stochastic processes, while increasing in the contribution of deterministic processes. Dispersal limitation was the dominant microbial assembly mechanism, followed by homogeneous selection, and then heterogeneous selection in the symbiotic bacterial community communities of amphibians between summer and autumn. Furthermore, higher niche width of the symbiotic bacterial community of amphibians was found in summer than autumn. Overall, these results demonstrated that seasonal variation influenced amphibian symbiotic bacterial community between summer and autumn.
爬行动物是受道路影响的主要野生脊椎动物类群之一,2019-2020年,采用路巡调查法对云南省普洱市思茅区爬行动物路杀现象进行了调查.结果发现,路杀爬行动物有7科22种100只,钝头蛇科的横纹钝头蛇Pareas margaritophorus、眼镜蛇科的银环蛇Bungarus multicinctus是路杀数量最多的物种,包括2种国家二级重点保护野生动物:闪鳞蛇Xenopeltis unicolor和三索蛇Coelognathus radiatus.爬行动物的路杀有3个高峰时间段,7:00-10:00时是最集中的路杀时间段.温度20-25℃是最集中的路杀温度范围.进一步的分析发现,爬行动物的路杀与其活动节律有关,7:00-10:00时的晒阳行为可能是路杀的主要诱因.
The Chinese giant salamander (Andrias davidianus), one of the largest extant amphibian species, has dramatically declined in the wild. As an ectotherm, it may be further threatened by climate change. Therefore, understanding the thermal physiology of this species should be the priority to formulate related conservation strategies. In this study, the plasticity in metabolic rate and thermal tolerance limits of A. davidianus larvae were studied. Specifically, the larvae were acclimated to three temperature levels (7 °C, cold stress; 15 °C, optimum; and 25 °C, heat stress) and two diet items (red worm or fish fray) for 20 days. Our results indicated that cold-acclimated larvae showed increased metabolic capacity, while warm-acclimated larvae showed a decrease in metabolic capacity. These results suggested the existence of thermal compensation. Moreover, the thermal tolerance windows of cold-acclimated and warm-acclimated larvae shifted to cooler and hotter ranges, respectively. Metabolic capacity is not affected by diet but fish-fed larvae showed superiority in both cold and heat tolerance, potentially due to the input of greater nutrient loads. Overall, our results suggested a plastic thermal tolerance of A. davidianus in response to temperature and diet variations. These results are meaningful in guiding the conservation of this species.
A new species of the Gekko (Squama ta: Gekkonidae) is described from the border of Sichuan and Yunnan Province, southwest China, based on distinct morphological and molecular features. Gekko jinjiangensis sp. nov. is distinguished from congeners by a combination of the following characters: size small (SVL 50.2-61.6 mm, n = 13); nares in contact with rostral; interorbital scales between anterior corners of the eyes 20-24; ventral scales between mental and cloacal slit 146-169; midbody scale rows 111-149; ventral scale rows 31-47; subdigital lamellae on first toe 8-11, on fourth toe 11-15; no webbing in the fingers and toes; with tubercles on uapper surface of fore and hind limbs; precloacal pores 4-5 in males; postcloacal unilateral tubercles 1-2; dorsal surface of body with 8-9 large greyish brown markings between nape and sacrum. In molecular analyses, the new species is sister to G. scabridus, but separated from them by approximately 9.9%-12.2% in genetic divergence as shown by a fragment of the partial mitochondrial ND2 gene. The new species is the highest Gekko with elevation range from 2000 to 2476 m. Further surveys are recommended to better understand the occurrence and population status of the new species.
玉龙龙蜥Diploderma yulongense(Mathey,Denzer,Hou&Wang 2012)于2012年根据 Andrews R C等1914年在玉龙雪山采集的历史馆藏标本命名.至今对该物种尚未进行过研究,对其自然生活史资料和分布范围知之甚少.2019年7月,作者在四川省凉山彝族自治州木里县下麦地乡采集到2号龙蜥属物种标本(采集号:2019ML0037♂,2019ML0038♀),经形态学检视和线粒体ND2基因序列重建分子系统发育关系,确定该2号标本为玉龙龙蜥,该种是四川分布新记录种.该发现将对玉龙龙蜥在我国地理分布的认知向东北方向延伸了 100余千米.
Cryptic diversity not only introduces confusion to taxonomic studies, but it also poses major challenges to conservation and environmental legislation. One such troubling group are the Mountain Dragons in the genus Diploderma in Southwest China. Previous studies have suggested that the genus contains considerable cryptic diversity, particularly in the D. flaviceps complex. Owing to taxonomic confusion, micro-endemic lineages are still neglected by the Chinese wildlife protection laws, despite their urgent conservation needs. Combining multivariate morphological and multi-locus phylogenetic data, we provide the first integrative systematic revision of the genus Diploderma. Specifically, we confirm that the six examined populations of D. cf. flaviceps from the upper Jinsha and Yalong River Valleys in Sichuan and Yunnan Provinces represent six cryptic, undescribed lineages, and we describe each of them as a new species. With the updated taxonomy and distribution information, we discuss the taxonomy of the D. flaviceps complex in Southwest China, provide an updated diagnostic key along with distributional ranges for all species of the genus, and discuss some of the suspicious records of other congeners in China. Lastly, we evaluate the IUCN status of each of the six new species and highlight the major challenges for Diploderma conservation in China due to delayed environmental legislation and misleading conservation assessments.
Background Owing to their incomplete adaptation to the terrestrial environment, amphibians possess complex cutaneous glandular systems. The skin glands not only regulate water loss and respiratory gas and salt exchange, but are also involved in defense against predators and microorganisms, social communication, and reproduction. These glands are distributed throughout the integument, but can accumulate in specific regions, forming visible outgrowths known as macroglands. Some macroglands are sexually dimorphic and mediate intersexual communication and reproductive success. The postaxillary gland is a sexually dimorphic macrogland in Nidirana pleuraden. Its biological function and its morphological and histochemical characteristics are unclear. In the present study, we describe the structure and ultrastructure of the postaxillary gland, and explore its main function. Results The postaxillary gland has a thinner epidermis than the dorsal region of N. pleuraden. In addition to ordinary serous glands (OSG), type I and II mucous gland (I MG & II MG), a type of specialized mucous gland (SMG) is also found to constitute the postaxillary gland. The SMG is larger than other gland types, and consists of high columnar mucocytes with basal nuclei arranged radially toward a lumen. SMGs are positive to periodic acid-Schiff stain and stained blue in Masson's trichrome stain. A discontinuous myoepithelial sheath lacking innervation encircles SMG mucocytes, and the outlets of such glands are X- or Y-shaped. Transmission electron microscopy reveals abundant secretory granules in SMG, which are biphasic, composed of an electron-opaque outer ring and a less electron-dense core. Lipid droplets, and organelles, such as rough endoplasmic reticulum and Golgi stacks, are located in the supranuclear cytoplasm of the mucocytes in SMG. Female N. pleuraden exhibits chemotaxis toward homogenate of the postaxillary gland, but male does not. On treatment with trypsin, this sexual attraction disappears. Conclusions The postaxillary gland of N. pleuraden is a male-specific macrogland that consists primarily of SMGs, together with OSGs, I MGs and II MGs. Other than their extremely large size, SMGs structurally and histochemically resemble many reported specialized gland types in amphibian sexually dimorphic skin glands. Secretions of the postaxillary gland are proteinaceous sexual pheromones, which are believed to attract females at male calling intermissions.
BACKGROUND:Owing to their incomplete adaptation to the terrestrial environment, amphibians possess complex cutaneous glandular systems. The skin glands not only regulate water loss and respiratory gas and salt exchange, but are also involved in defense against predators and microorganisms, social communication, and reproduction. These glands are distributed throughout the integument, but can accumulate in specific regions, forming visible outgrowths known as macroglands. Some macroglands are sexually dimorphic and mediate intersexual communication and reproductive success. The postaxillary gland is a sexually dimorphic macrogland in Nidirana pleuraden. Its biological function and its morphological and histochemical characteristics are unclear. In the present study, we describe the structure and ultrastructure of the postaxillary gland, and explore its main function. RESULTS:The postaxillary gland has a thinner epidermis than the dorsal region of N. pleuraden. In addition to ordinary serous glands (OSG), type I and II mucous gland (I MG & II MG), a type of specialized mucous gland (SMG) is also found to constitute the postaxillary gland. The SMG is larger than other gland types, and consists of high columnar mucocytes with basal nuclei arranged radially toward a lumen. SMGs are positive to periodic acid-Schiff stain and stained blue in Masson's trichrome stain. A discontinuous myoepithelial sheath lacking innervation encircles SMG mucocytes, and the outlets of such glands are X- or Y-shaped. Transmission electron microscopy reveals abundant secretory granules in SMG, which are biphasic, composed of an electron-opaque outer ring and a less electron-dense core. Lipid droplets, and organelles, such as rough endoplasmic reticulum and Golgi stacks, are located in the supranuclear cytoplasm of the mucocytes in SMG. Female N. pleuraden exhibits chemotaxis toward homogenate of the postaxillary gland, but male does not. On treatment with trypsin, this sexual attraction disappears. CONCLUSIONS:The postaxillary gland of N. pleuraden is a male-specific macrogland that consists primarily of SMGs, together with OSGs, I MGs and II MGs. Other than their extremely large size, SMGs structurally and histochemically resemble many reported specialized gland types in amphibian sexually dimorphic skin glands. Secretions of the postaxillary gland are proteinaceous sexual pheromones, which are believed to attract females at male calling intermissions.
Cryptic diversity not only introduces confusion to taxonomic studies, but it also poses major challenges to conservation and environmental legislation. One such troubling group are the Mountain Dragons in the genus in Southwest China. Previous studies have suggested that the genus contains considerable cryptic diversity, particularly in the . complex. Owing to taxonomic confusion, micro-endemic lineages are still neglected by the Chinese wildlife protection laws, despite their urgent conservation needs. Combining multivariate morphological and multi-locus phylogenetic data, we provide the first integrative systematic revision of the genus . Specifically, we confirm that the six examined populations of . cf. from the upper Jinsha and Yalong River Valleys in Sichuan and Yunnan Provinces represent six cryptic, undescribed lineages, and we describe each of them as a new species. With the updated taxonomy and distribution information, we discuss the taxonomy of the . complex in Southwest China, provide an updated diagnostic key along with distributional ranges for all species of the genus, and discuss some of the suspicious records of other congeners in China. Lastly, we evaluate the IUCN status of each of the six new species and highlight the major challenges for conservation in China due to delayed environmental legislation and misleading conservation assessments.