European marbled newts come in two species that have abutting ranges. The northern species, Triturus marmoratus, is found in France and the northern part of the Iberian Peninsula, whereas the southern species, T. pygmaeus, is found in the southwestern corner of the Iberian Peninsula. We study the intraspecific genetic differentiation of the group because morphological data show geographical variation and because the Iberian Peninsula is a recognized center of speciation and intraspecific genetic diversity for all kinds of organisms, amphibians included. We use target enrichment by sequence capture to generate c. 7 k nuclear DNA markers. We observe limited genetic exchange between the species, which confirms their distinctiveness. Both species show substantial genetic structuring that is only in part mirrored by morphological variation. Genetically differentiated groups are found in the south (T. marmoratus) and west (T. pygmaeus) of the species ranges. Our observations highlight the position of the Iberian Peninsula as a hotspot for genetic differentiation.

One of the major threats for the massive loss in global amphibian diversity is chytridiomycosis, caused by chytrid fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). Following its discovery in 2013, Bsal has emerged as a severe threat to the global survival of urodelans. In 2018, a study reported a high prevalence of Bsal (65.6%) in the Hong Kong newts (Paramesotriton hongkongensis, Near Threatened) of a southern China population adjacent to Hong Kong (HK). Uncertainty regarding the Bsal infection status of P. hongkongensis inhabiting HK raised deep concern over the risk of introducing Bsal from that population. We screened the skin swabs from wild individuals of P. hongkongensis, 15 sympatric amphibian species, and 16 imported amphibian species in HK for chytrids. We found that both Bsal and Bd occur in low prevalences in P. hongkongensis (Bsal 1.7%, 5/293; Bd 0.34%, 1/293), Hong Kong cascade frog, Amolops hongkongensis, family Ranidae (Bsal only, 5.26%, 1/19), and Asian common toad, Duttaphrynus melanostictus, family Bufonidae (Bsal only, 5.88%, 1/17), populations of HK, with infected individuals being asymptomatic, suggesting a potential role of these species as reservoirs of Bsal. Conversely, Bd, but not Bsal, was present on 13.2% (9/68) of imported amphibians, indicating a high chytrid introduction risk posed by international amphibian trade. Long-term surveillance of the presence of Bd and Bsal in wild and captive amphibians would be advisable, and we recommend that import and export of nonnative chytrid carriers should be prevented, especially to those regions with amphibian populations naïve to Bd and Bsal.

Mitochondrial genomes (mitogenomes) are valuable resources in molecular and evolutionary studies, such as phylogeny and population genetics. The complete mitogenomes of two crocodile newts, Tylototriton broadoridgus and Tylototriton gaowangjienensis, were sequenced, assembled, and annotated for the first time using next-generation sequencing. The complete mitogenomes of T. broadoridgus and T. gaowangjienensis were 16,265 bp and 16,259 bp in lengths, which both composed of 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and 1 control region. The two mitogenomes had high A + T content with positive AT-skew and negative GC-skew patterns. The ratio of non-synonymous and synonymous substitutions showed that, relatively, the ATP8 gene evolved the fastest and COI evolved the slowest among the 13 PCGs. Phylogenetic trees from BI and ML analyses resulted in identical topologies, where the Tylototriton split into two groups corresponding to two subgenera. Both T. broadoridgus and T. gaowangjienensis sequenced here belonged to the subgenus Yaotriton, and these two species shared a tentative sister group relationship. The two mitogenomes reported in this study provided valuable data for future molecular and evolutionary studies of the genus Tylotoriton and other salamanders.

The effects of newt motilin on the contractility of the isolated gastrointestinal (GI) tract from Japanese fire belly newts (newt) were examined to clarify whether motilin regulates GI motility in urodele amphibians. In addition, contractile responsiveness to motilins from seven species of vertebrates (human, chicken, turtle, alligator, axolotol, newt and zebrafish) were compared in GI preparations from three different animals (rabbit duodenum, chicken ileum and newt stomach) to determine the species-specific action of motilin. Newt motilin (10-10 M - 10-6 M) caused a contraction of cognate gastric strips, while the upper, middle, and lower intestinal strips were insensitive. The rank order of motilins for contractile activity in newt gastric strips was newt > alligator > axolotol > chicken > turtle > human ≫ zebrafish. On the other hand, newt motilin caused a weak contraction in the rabbit duodenum (human > alligator = chicken > turtle > newt ≧ axolotol > zebrafish), and it was ineffective in the chicken ileum (chicken > turtle > alligator > human ≫ newt, axolotol and zebrafish). This study demonstrates that motilin induces contraction in the GI tract of a urodele amphibian, the newt, in a region (stomach)-specific manner and further indicates that a ligand-receptor interaction of the motilin system is a species-specific manner probably due to differences in the amino acid sequence of motilin.

A new species of the genus Tylototriton sensu lato from Tongzi County, Guizhou Province, China was described. Molecular phylogenetic analyses based on mitochondrial 16S and ND2 gene sequences indicated the new species as the most closely related species of T. dabienicus in Henan. The new species could be identified from its congeners by a combination of the following morphological characters: (1) body size medium (TOL 120.5135.1 mm and SVL 61.165.9 mm in males, and TOL 123.5127.6 mm and SVL 66.769.2 mm in females); (2) gular fold present; (3) the tail length shorter than the snout-vent length; (4) the distal ends and ventral surfaces of digits, peripheral area of cloaca, and the lower margin of tail orange; (5) the distal tips of the limbs greatly overlapping when the fore and hind limbs being pressed along the trunk; (6) fingertips reaching to the level beyond the snout when the forelimbs being stretched forward; (7) nodule-like warts on body sides continuous and no obvious. The new species is known only from the montane forests of Huanglian Nature Reserve, Tongzi County, Guizhou Province, China. We recommend the new species to be listed as Critically Endangered.

The Paramesotriton Chang, 1935 genus of Asian warty newts is the second most diverse genus in the family Salamandridae, currently containing 14 recognized species from northern Vietnam to southwest-central and southern China. Although species of this genus have been included in previous phylogenetic studies, the origin and interspecific relationships of the genus are still not fully resolved, especially at key nodes in the phylogeny. In this study, we sequenced mitochondrial genomes and 32 nuclear genes from 27 samples belonging to 14 species to reconstruct the interspecific phylogenetic relationships within Paramesotriton and explore its historical biogeography in southern China. Both Bayesian inference and maximum-likelihood analyses highly supported the monophyly of Paramesotriton and its two recognized species groups ( P. caudopunctatus and P. chinensis groups) and further identified five hypothetical phylogenetic cryptic species. Biogeographic analyses indicated that Paramesotriton originated in southwestern China (Yunnan-Guizhou Plateau/South China) during the late Oligocene. The time of origin of Paramesotriton corresponded to the second uplift of the Himalayan/Qinghai-Xizang (Tibetan) Plateau (QTP), rapid lateral extrusion of Indochina, and formation of karst landscapes in southwestern China. Principal component analysis (PCA), independent sample t-tests, and niche differentiation using bioclimatic variables based on locations of occurrence suggested that Paramesotriton habitat conditions in the three current regions (West, South, and East) differ significantly, with different levels of climatic niche differentiation. Species distribution model (SDM) predictions indicated that the most suitable distribution areas for the P. caudopunctatus and P. chinensis species groups are western and southern/eastern areas of southern China. This study increases our knowledge of the taxonomy, biodiversity, origin, and suitable distribution areas of the genus Paramesotriton based on phylogenetic, biogeographic, and species distribution models.
亚洲蝾螈瘰螈属（ Paramesotriton Chang, 1935）是蝾螈科物种多样性第二高的属，目前有14个公认的有效物种（仅次于有36个物种的疣螈属 Tylototriton），分布于越南北部至中国西南部、中部和南部地区。尽管瘰螈属的物种已被纳入到先前的系统发育研究中，但该属的起源和种间关系仍未完全解析，特别是在系统发育的关键节点上。该研究对瘰螈属14个物种的27个样本进行线粒体基因组和32个核基因测序，重建了瘰螈属的种间系统发育关系，探讨了中国南方地区瘰螈属的历史生物地理学。贝叶斯推断和最大似然法分析都高度支持瘰螈属及其尾斑瘰螈种组（ P. caudopunctatus species group）和中国瘰螈种组（ P. chinensis species group）单系性，并识别出5个系统发生隐蔽种。生物地理学分析表明，瘰螈属在渐新世晚期（约25.42百万年）起源于中国西南地区（云贵高原/华南）。瘰螈属的起源时间与喜马拉雅/青藏高原的第二次隆起、中南半岛的快速侧向挤压以及中国西南地区岩溶地貌的形成相一致。主成分分析、独立样本 t检验和基于发生点生物气候变量的生态位分化结果表明，瘰螈属3个当前的分布区域（西部、南部、东部）栖息地的生境条件存在显著差异，且具有不同程度的气候生态位分化。物种分布模型预测结果表明，尾斑瘰螈种组和中国瘰螈种组最适合的分布区域在中国南方的西部和南部/东部地区。综上所述，该研究在系统发育、生物地理和物种分布模型的基础上，增加了对瘰螈属在分类学、生物多样性起源和适宜分布区等方面的认识。.

Evolutionary biologists are always interested in deciphering the geographic context of diversification, therefore they introduced the concept of comparative phylogeography, which helps to identify common mechanisms that contribute to shared genetic structures among organisms from the same region. Here, we used multi-locus genetic data along with environmental data to investigate shared phylogeographic patterns among three Asian-endemic newt genera, Cynops, Paramesotriton and Pachytriton, which occurred in montane/submontane streams or ponds in southern China. Our 222 samples from 78 localities covered the entire range of the three genera and represented the largest dataset of this group to date. We reconstructed matrilineal genealogies from two protein-coding, mitochondrial genes, and gene network from two nuclear genes. We also estimated divergence times of major cladogenetic events and used occurrence data to evaluate niche difference and similarity between lineages. Our results revealed a common basal split in all three genera that corresponds to the separation of two geographic terrains of southern China. Those ancient divergence occurred during middle to late Miocene and likely correlate with paleoclimatic fluctuations caused by the uplift of the Qinghai-Xizang (Tibet) Plateau (QTP). Particularly, the strengthening and weakening of Asian summer monsoons during the Miocene may have profoundly impacted southern China and led to repeatedly vicariance in those newts. However, despite differences in realized niches between lineages, there is no evidence for divergence of fundamental niches. Preservation of old newt matriline lineages in mountains of southern China suggests that the region acts as both museums and cradles of speciation. Based on those results, we advocate a multi-pronged protection strategy for newts in the three genera.
复杂地理环境对物种多样性地理格局的影响是进化生物学家研究的热点问题之一，基于多类群的比较系统地理学研究有助于理解来自同一地区的不同生物类群间遗传结构形成的驱动机制。亚洲蝾螈类的三个属（ Cynops、 Paramesotriton和 Pachytriton）的地理分布均横跨中国南方的第二和第三级阶梯，这两个不同的地理环境是否促进了相似物种多样性地理分布格局的形成尚不清楚。该研究采集了来自78个地点的222份样本，涵盖了这三个属的在中国南方分布范围。基于两个线粒体基因和两个核基因数据，分别构建了三属的系统发育关系和单倍型网络图，并估算了该类群的起源与物种分化时间，并进行了祖先地重建的分析。同时，我们还使用各物种的地理环境数据来评估各支系之间的生态位差异和相似性。研究结果发现，这三个属都有一个共同的系统地理分布格局，三个属的内部均分化成两个大的进化支系，分布对应着中国南方的第二和第三级阶梯。有意思的是这一相似的系统地理格局并非同时形成的，而是三次独立发生的分化事件。这些古老的分化发生在中新世中期至晚期，可能与古气候的波动有关，特别是中新世期间亚洲夏季季风反复的增强和减弱可能对中国南方产生了较大的影响，并导致这些蝾螈类的多次分化。然而，尽管第二和第三阶梯的支系之间具有地理环境的差异，但没有证据表明它们的分化是生态位分化驱动的结果。另外，我们的结果发现中国南方的山区不仅保存了很多古老的蝾螈类物种，还促进了大量新物种的产生，该地区既是物种形成的“博物馆”，也是物种形成的“摇篮”。最后，我们基于该研究的结果对这三个类群物种的保护策略提供了参考和依据。.

The Hengduan Mountains Region (HMR) is the largest \"evolutionary frontier\" of the northern temperate zone, and the origin and maintenance of species in this area is a research hotspot. Exploring species-specific responses to historical and contemporary environmental changes will improve our understanding of the role of this region in maintaining biodiversity. In this study, mitochondrial and microsatellite diversities were used to assess the contributions of paleogeological events, Pleistocene climatic oscillations, and contemporary landscape characteristics to the rapid intraspecific diversification of Liangshantriton taliangensis, a vulnerable amphibian species endemic to several sky-island mountains in the southeastern HMR. Divergence date estimations suggested that the East Asian monsoon, local uplifting events (Xigeda Formation strata), and Early-Middle Pleistocene transition (EMPT) promoted rapid divergence of L. taliangensis during the Pleistocene, yielding eight mitochondrial lineages and six nuclear genetic lineages. Moreover, population genetic structures were mainly fixed through isolation by resistance. Multiple in situ refugia were identified by ecological niche models and high genetic diversity, which played crucial roles in the persistence and divergence of L. taliangensis during glacial-interglacial cycles. Dramatic climatic fluctuations further promoted recurrent isolation and admixing of populations in scattered glacial refugia. The apparent mitonuclear discordance was likely the result of introgression by secondary contact and/or female-biased dispersal. Postglacial expansion generated two major secondary contact zones (Ganluo (GL) and Chuhongjue (CHJ)). Identification of conservation management units and dispersal corridors offers important recommendations for the conservation of this species.
横断山区(HMR)是北温带最大的“进化前沿”，区域的物种起源和维持机制一直是研究热点。探索物种对历史和现代环境变化的特异响应有助于更深入地理解区域生物多样性的形成和维持机制。该研究以分布于横断山东南部高山峡谷 “空岛区”的易危两栖动物——大凉螈( Liangshantriton taliangensis) 为目标物种，运用多个线粒体基因及微卫星多态位点作为遗传标记，结合历史气候及景观特征，探究了古地质事件、更新世气候波动及景观环境对该物种快速分化的作用。结果显示东亚季风、局地(西格达组地层)抬升事件、早-中更新世气候转变时期（EMPT）的冰川发育与消退促进了大凉螈种群的快速分化，共分化出8个线粒体遗传支系及6个微卫星遗传簇。种群扩散主要受到全年及干旱季降水量、植被覆盖度、海拔等景观因子影响，并进一步促进了种群结构的形成。生态位模型结合遗传多样性分析揭示大凉螈存在多个原地冰期避难所，这对该螈在冰期-间冰期旋回时期种群的分化与维持起着关键作用。气候波动促进了分散的避难所间各种群反复混合与隔离，并存在两个主要的二次接触区（甘洛（GL）和处洪觉（CHJ））。多次的二次接触和凉山种群偏雌扩散的综合作用可能是核质不一致的主要成因。基于研究结果，提出了建立两个保护管理单元、7个优先保护种群以及维护关键扩散路径等保护管理建议。.

Four new water mite species of the genus Hygrobates, subgenus Lurchibates (Acari, Hydrachnidia, Hygrobatidae) are described. Hygrobates (Lurchibates) macrochela sp. nov. Goldschmidt, Nishikawa Shimano is described in male and female; Hygrobates (Lurchibates) malosimilis sp. nov. Goldschmidt, Nishikawa Shimano is described in male, both new water mite species were collected from newts of the species Pachytriton inexpectatus Nishikawa, Jiang, Matsui Mo, 2011; Hygrobates (Lurchibates) incognitus sp. nov. Goldschmidt, Nishikawa Shimano is described in female collected from newts of the species Paramesotriton guangxiensis (Huang, Tang and Tang, 1983); Hygrobates (Lurchibates) fragmentarius sp. nov. Goldschmidt, Nishikawa Shimano is described in a single severely fragmented specimen (sex could not be determined) collected from a newt of the species Paramesotriton yunwuensis Wu, Jiang, and Hanken, 2010. Principal differences between the subgenus Lurchibates and the nominal subgenus Hygrobates s. str. are illustrated and discussed as well as the sexual dimorphism of Lurchibates. Morphometric analyses confirmed the morphological differences of ten out of the eleven so far described species (H. (L.) fragmentarius could not be included in the analysis); two morphological groups became evident mainly based upon the shape of the anterior coxae. These analyses as well provide an idea of possible phylogenetic relationships among the species. A key to all currently known species of the subgenus Lurchibates is given. So far the subgenus is restricted to SE-Asia, a map showing the distribution of all species is presented.

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