Key appendage innovations have driven the origin and expansion of arthropods, such as spinnerets enabling spiders to occupy three-dimensional space and diversify into more than 53,000 species. Here, we investigate the genetic basis of spinneret emergence in spiders by examining the complex history and functional importance of arachnid genome evolution. Using chromosome-scale genomes from newly sequenced spiders and the whip scorpion, we integrate evidence from macrosynteny and phylogenetic analyses to provide further strong support for a whole-genome duplication (WGD) event that occurred during early Arachnopulmonata evolution. Following this event, the abdominal-A gene pair not only exhibits functional divergence but also jointly facilitates the emergence of spinnerets. Furthermore, we integrated single-cell transcriptomic analyses and functional validation to confirm that the dachshund-1 gene also regulates spinneret development. The network of duplicated gene pairs may form a cornerstone in the origin and evolution of key morphological traits, revealing that the long-term effects of ancient WGDs on innovation and diversification also occurred in arthropods.

Three new species of Hippasa are described from China and adjacent regions of Thailand and Vietnam: H. modog sp. nov. (♂♀, Xizang, China), H. pulmoniformis sp. nov. (♂♀, Guangxi, China, and Hải Phòng Province, Vietnam), and H. thailandica sp. nov. (♂♀, Suan Phueng, Thailand). A new genus, Pandacosa gen. nov., is established to accommodate Hippasa bifasciata Buchar, 1997 (previously known only from females in Bhutan). The male of Pandacosa bifasciata (Buchar, 1997) comb. nov. is described for the first time based on specimens from Yunnan, China. A distribution map for all treated species is provided.

Five new cave-dwelling species and one newly recorded litter-dwelling species belonging to the family Tetrablemmidae are described from Thailand, i.e., Ablemma erna Lehtinen, 1981 (♂♀), A. theppratan Tong & Li, sp. nov . (♂♀), A. yamae Tong & Li, sp. nov . (♂♀), Shearella khaoplu Tong & Li, sp. nov . (♂), S. thamphothisat Tong & Li, sp. nov . (♂) and Tetrablemma lorkor Tong & Li, sp. nov . (♂). Diagnoses and illustrations for all six species are given.

Two new species of Brommella from China are described: B. zhengjuni Lin & Li, spec. nov. (♂♀) from Xizang Autonomous Region, and B. zujiani Lin & Li, spec. nov. (♂♀) from Guangdong Province. Diagnoses, descriptions, photos and a distribution map are provided.

Three new species of the genus Trilacuna Tong & Li, 2007 are described from China: T. batang Tong & Li, sp. nov . (♂♀) and T. kangding Tong & Li, sp. nov . (♂♀) from Sichuan Province, and T. shennongjia Tong & Li, sp. nov . (♂♀) from Chongqing Municipality and Hubei Province. Detailed morphological descriptions, diagnostic characteristics and morphological photographs of the new species are provided.

The Pan‐Himalayan region harbors exceptional biodiversity, yet the origins and underlying mechanisms driving this remarkable diversity remain poorly understood, especially among species‐rich invertebrates. Pimoa spiders exhibit an intercontinental disjunct distribution across three major mountain regions: the Rockies, the Alps, and the Pan‐Himalaya. Notably, in the Pan‐Himalaya, Pimoa occurs at significantly higher elevations and exhibits far greater species diversity than in the other two regions, making it an ideal model for studying invertebrate diversification in this area. We integrated extensive genetic data (59 new transcriptomes and over 22 700 newly generated DNA sequences from 393 samples), along with distribution and climatic data, to explore the origins and drivers of the rich diversity of Asian Pimoa in the Pan‐Himalaya. Our findings indicate that Pan‐Himalayan Pimoa spiders originated from widely distributed ancestors in North America and Asia. During the Miocene, they dispersed southward from northeast Asia to south China and the Pan‐Himalaya, experiencing rapid diversification. Climatic niche modeling and ancestral reconstruction analyses revealed niche divergence between Pan‐Himalayan Pimoa and their ancestors, particularly in elevation and temperature. Gene selection analyses showed that high‐elevation adaptations primarily involve enhanced energy metabolism, hypoxia resistance, and DNA repair mechanisms. These results suggest that ecological niche differentiation, high‐elevation adaptation, and rapid diversification during the Miocene are crucial factors shaping the rich diversity of Asian Pimoa in the Pan‐Himalaya. Our study, which integrates genetic, distributional, and climatic data, provides a novel framework for understanding invertebrate diversification in the Pan‐Himalaya.

Eight new species of the genus Ischnothyreus Simon, 1893 are described from Hainan, China: I. bawangling Tong & Li, sp. nov . (♂♀), I. diaoluoshan Tong & Li, sp. nov . (♂♀), I. hongxin Tong & Li, sp. nov . (♂♀), I. jianfengling Tong & Li, sp. nov . (♂♀), I. limuling Tong & Li, sp. nov . (♂♀), I. liudao Tong & Li, sp. nov . (♂♀), I. luobidong Tong & Li, sp. nov . (♂♀) and I. wuzhishan Tong & Li, sp. nov . (♂). Diagnoses and illustrations for all eight species are given.

Rafting dispersal has been proposed as a way for coastal species to track climate-driven niche shifts. However, little information exists on how rafting species disperse and adapt to shifting environmental conditions, particularly ocean currents and salinity. Here, we integrate dispersal simulations, ecological genomics, and salinity stress experiments to investigate rafting dynamics and adaptive shifts in widely distributed crustaceans across the Indo-Australian Archipelago. We develop a quantified model to examine asymmetric gene flow between populations driven by recent seasonal oceanographic shifts. Our climatic and dispersal models suggest that rafting populations must cope with increasing salinity fluctuation caused by rapidly-shifting oceanic connectivity patterns. Our genomic data provide evidence for recent selective sweeps at osmoregulatory loci, and key duplications at glycoside hydrolase gene families. Our experimental data reveal plastic expression of osmoregulatory genes required for survival during long-distance rafting voyages. These synergies between rafting dispersal and genomic change highlight the potential for rafting species to adapt to rapidly shifting oceanographic conditions.

Four species of the genus Trilacuna Tong & Li, 2007 from Xizang, China are recognized, including three new species and one newly recorded species: T.bangla Grismado & Ramírez, 2014, T.mainling Tong & Li, sp. nov. (♂♀), T.metok Tong & Li, sp. nov. (♂♀) and T.zayu Tong & Li, sp. nov. (♂♀). Descriptions, diagnoses and photomicroscopy images are provided.

Six new species, belonging to three species groups of Clubiona Latreille, 1804 are described from both males and females: C.huntianling Yu & Li, sp. nov., C.rouqiu Yu & Li, sp. nov. and C.yinyangjian Yu & Li, sp. nov. from the corticalis group; C.huojianqiang Yu & Li, sp. nov. and C.qiankunquan Yu & Li, sp. nov. from the trivialis group; C.nezha Yu & Li, sp. nov. from the zilla group. These species are currently known to occur only in subtropical forests, Sichuan, China. The DNA barcodes of all species were obtained for species delimitation, matching of sexes and future use.

Two new genera and seven new species of the subtribe Plexippina Simon, 1901 are reported from Southwest China based on both morphological and molecular evidence. They are Chuanattus deelemanae C. Wang, Mi & Li, gen. et sp. nov. (♂♀), Dianattus proszynskii C. Wang, Mi & Li, gen. et sp. nov. (♂♀), Yaginumaella daolangi C. Wang, Mi & Li, sp. nov. (♂♀), Y. medog C. Wang, Mi & Li, sp. nov. (♂♀), Y. qianlei C. Wang, Mi & Li, sp. nov. (♂♀), Y. spinapophysis C. Wang, Mi & Li, sp. nov. (♂♀), and Y. xiaoqingi C. Wang, Mi & Li, sp. nov. (♂♀). Diagnostic photos and a distributional map of those new species are provided. The genus Yaginumaella Prószyński, 1979 is reviewed, and 21 new and 34 restored combinations transferred from Ptocasius Simon, 1885 except Y. pentamaculata (Hu, 2001), comb. nov. from Menemerus Simon, 1868, are proposed: Thyene incognita (Żabka, 1981), comb. nov., Y. angulata (Yang & Peng, 2023), comb. nov., Y. badongensis Song & Chai, 1992, comb. rest., Y. bhutanica Żabka, 1981, comb. rest., Y. bulbosa Peng, Tang & Li, 2008, comb. rest., Y. cambridgei Żabka, 1981, comb. rest., Y. circula (Yang & Peng, 2023), comb. nov., Y. danzhu (Yang & Peng, 2023), comb. nov., Y. davidi (Yang & Peng, 2023), comb. nov., Y. falcata Zhu, Zhang, Zhang & Chen, 2005, comb. rest., Y. filiforma (Yang & Peng, 2023), comb. nov., Y. foliolata (Yang & Peng, 2023), comb. nov., Y. gemina (Yang & Peng, 2023), comb. nov., Y. gogonaica Żabka, 1981, comb. rest., Y. helvetorum Żabka, 1981, comb. rest., Y. hubeiensis Li, Wang, Irfan & Peng, 2018, comb. rest., Y. hybrida Żabka, 1981, comb. rest., Y. intermedia Żabka, 1981, comb. rest., Y. jietouensis (Yang & Peng, 2023), comb. nov., Y. linzhiensis (Hu, 2001), comb. nov. (placed initially in Ptocasius), Y. longapophysis (Yang & Peng, 2023), comb. nov., Y. longlingensis (Yang & Peng, 2023), comb. nov., Y. lushiensis Zhang & Zhu, 2007, comb. rest., Y. montana Żabka, 1981, comb. rest., Y. nepalica Żabka, 1980, comb. rest., Y. nobilis Żabka, 1981, comb. rest., Y. nova Żabka, 1981, comb. rest., Y. orientalis Żabka, 1981, comb. rest., Y. originalis Żabka, 1981, comb. rest., Y. pilosa Żabka, 1981, comb. rest., Y. pseudoflexa Liu, Yang & Peng, 2016, comb. rest., Y. pulchella Li, Wang, Irfan & Peng, 2018, comb. rest., Y. rectangula (Yang & Peng, 2023), comb. nov., Y. robusta (Yang & Peng, 2023), comb. nov., Y. senchalensis Prószyński, 1992, comb. rest., Y. silvatica Żabka, 1981, comb. rest., Y. simoni Żabka, 1981, comb. rest., Y. songi (Logunov, 1995), comb. nov., Y. stemmleri Żabka, 1981, comb. rest., Y. strandi Żabka, 1981, comb. rest., Y. subhubeiensis (Wang, Mi & Peng, 2023), comb. nov., Y. supina Żabka, 1981, comb. rest., Y. tenella Żabka, 1981, comb. rest., Y. tengchongensis (Yang & Peng, 2023), comb. nov., Y. tenzingi Żabka, 1980, comb. rest., Y. thakkholaica Żabka, 1980, comb. rest., Y. thimphuica Żabka, 1981, comb. rest., Y. umbellulata (Yang & Peng, 2023), comb. nov., Y. urbanii Żabka, 1981, comb. rest., Y. variegata (Logunov, 1995), comb. nov., Y. versicolor Żabka, 1981, comb. rest., Y. wangdica Żabka, 1981, comb. rest., Y. wuermli Żabka, 1981, comb. rest., Y. zonata (Yang & Peng, 2023), comb. nov. Pancorius lobatus (Peng, Tso & Li, 2002), comb. nov. is also proposed (transferred from Yaginumaella and it could be a junior synonym of Pancorius submontanus Prószyński, 1992). Ptocasius zabkai Yang & Peng, 2023 is assigned as a synonym of Y. zonata.

BACKGROUND: Mountain uplift has been recognized as a critical driver of adaptive evolution and species diversification. Hypochilidae, an ancient and relict spider family, is predominantly found in montane regions. However, the factors promoting speciation within this family remain poorly understood. RESULTS: We utilized multi-locus data from 97% of Hypochilidae species, including 27 mitochondrial genomes, to construct a robust phylogenetic tree. Time-calibrated analyses reveal that Hypochilidae originated in the Late Jurassic period. In North America, the genus Hypochilus diversified in association with relatively ancient orogenic events, particularly the uplift of the Rocky Mountains, California Mountains, and southern Appalachians, which mainly occurred prior to the Oligocene. In contrast, the Asian genus Ectatosticta exhibited a rapid diversification pattern, spreading from the southern to the northeastern regions of the Qinghai-Tibet Plateau (QTP) after the Miocene. The species accumulation and net diversification rates of Asian Ectatosticta were significantly higher than those of North American Hypochilus, with a notable acceleration in diversification rates observed in BAMM software. CONCLUSION: Mountain orogeny has profoundly influenced the speciation of the ancient and relict spider family Hypochilidae, with the stepwise uplift of the QTP driving the diversification and radiation of Asian lineages.

Climatic upheavals throughout Earth’s history have driven species to subterranean refugia, where stable microclimates buffer environmental extremes. The spider family Pimoidae, relict lineages sensitive to thermal fluctuations, exemplifies this climate-driven habitat transition. Here, we present the first chromosome-level genome of Pimoa clavata, a troglophilic spider endemic to Beijing’s mountainous caves. Combining PacBio HiFi and Hi-C sequencing, we assembled a 1.94 Gb genome with 29 scaffolds in chromosomes level, which were further subjected to comprehensive annotation. The well-annotated genome of this species provides foundational insights into the genomic basis of subterranean adaptation, offering critical resources for evolutionary genomics and conservation of climate-vulnerable cave species.

China exhibits remarkable diversity of the spider genus Belisana Thorell, 1898, while Sichuan Province has recorded only one species, Belisanamaoer Yao & Li, 2020. In this study, four species were collected in eastern Sichuan by canopy fogging. These comprise two new species, Belisanamiyi Wang, Li & Yao, sp. nov. and B.tongjiang Wang, Li & Yao, sp. nov., as well as two known species, B.tongi Zhang, Li & Yao, 2024 and B.yanhe Chen, Zhang & Zhu, 2009, which are reported from Sichuan for the first time. A distribution map of all five species is provided.

Aim To test how evolutionary processes of spiders in mountain ranges of eastern China were in response to environmental changes, we analyze the correlation between diversification of the Pardosa laura species complex (Araneae, Lycosidae) and historical climates and mountains in this region.Methods We reconstruct phylogenetic relationships and patterns of phylogeography and genetic diversity using mtDNA data from samples spanning the full range of the species complex P. laura in eastern China.Results The P. laura species complex clustered into four lineages: Lineage I includes five haplotypes from the areas to the north of the Yinshan-Yanshan Mountains; Lineage II consists of 23 haplotypes from the areas between the Qinling Mountains-Huaihe River Line and the Nanling Mountains; Lineage III and IV are composed of 21 and 62 haplotypes, respectively, from the areas between the Yinshan-Yanshan Mountains and the Nanling Mountains. Each lineage corresponds to that, grouped from haplotype network analyses, with the same geographic distribution areas. All four lineages initially diversified during about 1.43 and 0.24 Ma ago (Ma) in relation to the Pleistocene glacial-inglacial cycles. The biogeographic reconstructions suggest that the species complex P. laura most likely originated in central China around 7.68 (11.17-4.85) Ma in relation to the recent (approximately 8 Ma) expansion of grasslands and retraction of forests. The inter-colony dispersal between central China and northeastern China occurred during the late Neogene, between around 7.68 and 3.14 Ma. Central China is an important dispersal center, with dispersal to southwestern and northern China between the late Pliocene and middle Pleistocene, approximately 3.14-2.89 and 2.89-1.43 Ma, respectively.Main Conclusions The contemporary genetic structure of the P. laura species complex presents a high correlation between lineages and geographic distribution. The historical phylogeographic patterns suggested that the late Cenozoic climate changes and the mountainous corridors and isolation events, as well as the lineage dispersals and ecological adaptations shaped the diversification of a spider species complex in eastern China over long timescales.

The sea–land transition is one of the most dramatic evolutionary changes and requires an adaptive genetic response to salinity changes and osmotic stress. Here, we used multi-species genomes and multi-tissue transcriptomes of the talitrid crustaceans, a living sea–land transition model, to investigate the adaptive genetic changes and osmoregulatory organs that facilitated their salinity adaptation. Genomic analyses detected numerous osmoregulatory genes in terrestrial talitrids undergoing gene family expansions and positive selection. Gene expression comparisons among species and tissues confirmed the gill being the primary organ responsible for ion transport and identified the genetic expression variation that enable talitrids to adapt to marine and land habitats. V-type H+-ATPases related to H+ transport play a crucial role in land adaptations, while genes related to the transport of inorganic ions (Na+, K+, Cl−) are upregulated in marine habitats. Our results demonstrate that talitrids have divergent genetic responses to salinity change that led to the uptake or excretion of ions in the gills and promoted habitat adaptation. These findings suggest that detecting gene expression changes in talitrids presents promising potential as a biomarker for salinity monitoring.

Eight new species and one known species of the oonopid spider genus Orchestina Simon, 1882 are described or recorded based on material collected from forest canopy of Xishuangbanna, Yunnan Province, southwestern China: O. alata sp. nov. (♂♀), O. aureola Tong & Li, 2011 (♂♀), O. caixiaae Tong & Li, sp. nov. (♂♀), O. longituba Tong & Li, sp. nov. (♂♀), O. qingyuani Tong & Li, sp. nov. (♂♀), O. subconcava Tong & Li, sp. nov. (♂♀), O. sublongituba Tong & Li, sp. nov. (♂♀), O. tentoria Tong & Li, sp. nov. (♂♀) and O. xuexing Tong & Li, sp. nov. (♂♀). An identification key to these nine species is provided.

Two new species of the genus Trilacuna Tong & Li, 2007, T.manhao Tong & Li, sp. nov. (♂♀) and T.mopanshan Tong & Li, sp. nov. (♂♀), are described from Yunnan, China. Descriptions, diagnoses, photomicroscopy images and a key to species of Yunnan Province are provided.