The unique geomorphology of rivers in the eastern Himalaya has long intrigued geologists, yet their drainage history remains debated. Drainage reorganization can have a significant impact on genetic differentiation in freshwater taxa. This study employs the cold-adapted fish genus Schizothorax as a biogeographic proxy to reconstruct the evolutionary history of the Yarlung Tsangpo-Brahmaputra River (YTB), with a focus on a prominent hanging valley tributary-trunk stream system. Phylogeographic analyses of mitochondrial cyt b gene sequences identified a monophyletic QTP-YGP clade comprising species from the Qinghai-Tibet Plateau (QTP) and the Yunnan-Guizhou Plateau (YGP). Within the QTP-YGP lineage, YTB species represent the earliest diverging clade. In contrast, species from the Indus and Ganges basins are more closely related to congeners from the southeastern QTP and YGP. The YTB assemblage is further subdivided into two distinct clades. Molecular dating suggests that the YTB lineage diverged from the broader QTP-YGP group during the early Late Miocene, with the two YTB clades separating in the Late Miocene. We propose that a paleo-Yarlung Tsangpo-Dingba (Dibang)-Brahmaputra river and a Yigong-Parlung-Zayul (Lohit) river were established prior to the Late Miocene and were subsequently captured by the lower Yarlung Tsangpo River-via the Siang and Zhaqu, respectively-during the late Miocene and Quaternary. The modern YTB drainage configuration was established by the late Early Pleistocene. This study underscores the importance of integrating genetic, fauna and geomorphological data to understand the complex evolution of drainages in the eastern Himalayas.

Migratory fishes connect ecosystems and support fisheries and water security, yet their movements and population linkages remain poorly resolved at global scales. Biogeochemical tags (trace elements or stable isotopes) recorded in fish bioarchives provide retrospective evidence of migration, natal origin, and connectivity, offering a temporal perspective that extends beyond the inherently short-term scope of direct tracking methods. Here, we synthesize 1305 studies published between 1973 and 2023 to quantify global patterns, biases, and gaps in the biogeochemical tagging of migratory fish. Organizing the literature into ten research themes and distinguishing research effort (publication-level attention) from sampling effort (empirical spatial coverage), we find that publication growth has not translated into proportional gains in taxonomic, geographic, or life-history representativeness. Approximately one-sixth of known migratory fish species have been investigated using biogeochemical tagging, with research disproportionately concentrated on commercially important taxa, later life stages, and otolith-based archives. Coverage patterns are consistent with interacting constraints in bioarchive availability, tracer sensitivity, environmental baseline coverage, and analytical tractability, concentrating applications in contexts that generate strong chemical contrasts. Where environmental baselines are sparse or mismatched, biogeochemical inference is less comparable across studies and difficult to scale across regions and systems. Reconciling monitoring demand with research effort and baseline supply across global fishing regions highlights extensive areas where high migratory fish richness coincides with limited inferential capacity. We outline priorities for advancing biogeochemical tagging from case studies to decision-ready monitoring systems through improved baselines, interoperability, uncertainty treatment, and management-oriented implementation strategies.

Investigating the patterns and drivers of different diversity facets enhances our understanding of species distributions and has the potential to inform conservation strategies. However, only a few studies have explored how phylogenetic diversity relates to multiple ecogeographical processes at broad scales, especially in freshwater ecosystems. Here, we used a comprehensive freshwater fish dataset covering 165 hydrological units spanning four major zoogeographical regions in China and adjacent areas to examine how energy-availability, history, area-heterogeneity and spatial factors drive fish phylogenetic alpha and beta diversity within and among study regions. Our results showed that phylogenetic alpha and beta diversity were generally higher in the climatically more benign and low-altitude East and South Asia regions. In contrast, high-altitude HUs of Central Asia exhibited the lowest phylogenetic alpha diversity but comparatively high beta diversity, whereas the Palearctic region showed the highest phylogenetic alpha diversity and the lowest beta diversity. Moreover, we found higher deviation between taxonomic and phylogenetic beta diversity in Central Asia and Palearctic regions compared to other regions, indicating that lineage turnover within these zoogeographical regions predominantly involves closely related taxa. Hierarchical partitioning suggested that present-day phylogenetic diversity patterns of freshwater fish across China and adjacent areas were strongly influenced by climatic and geologic history, while spatial processes became increasingly important in shaping phylogenetic beta diversity at regional scales, where hydrological units experienced similar environmental and historical contexts. These findings highlight the persistent imprint of historical contingencies and spatial structuring on the evolutionary diversity of freshwater fish faunas, emphasizing the need for integrating explicit phylogenetic information into regional conservation and management planning.

The Lhalu Wetland National Nature Reserve, the largest natural urban wetland on the Qinghai-Tibet Plateau, plays a critical role in maintaining regional ecological balance and biodiversity. However, the baseline biodiversity of this reserve remains unclear because of the extensive temporal span of historical records, shifts in taxonomic systems, and inconsistent survey methodologies, which impedes a robust scientific understanding of its ecological dynamics. This study systematically compiled and taxonomically verified species records from over 50 sources spanning the 1950s to the present. The records cover plants, fish, birds, and amphibians/reptiles, thereby resolving issues of synonyms, homonyms, and misidentifications. Each species record is annotated with its original survey time, allowing users to distinguish historically reported occurrences from those recorded in recent surveys. Species accumulation curves were constructed for major taxa and compared with 45-year climatic trends (1979-2023) and socioeconomic indicators for Lhasa City. A total of 438 vascular plant species (82 families, 251 genera) and 311 animal species (39 orders, 98 families), including 30 fishes, 174 birds, and 11 amphibians/reptiles, were documented. Invasive species comprised 55 alien plants and 13 alien fishes, while 4 plant and 46 animal species are under national protection. Temporal synchrony between increases in alien taxa and anthropogenic pressures (gross domestic product (GDP) and population growth, infrastructure development) suggests that human activities may be a potential driver of biodiversity change, but formal causal inference is precluded by heterogeneity in survey methods and sampling effort. This work provides a structured dataset of the biodiversity baseline of the Lhalu Wetland and offers a descriptive assessment of its temporal patterns in relation to climate and human disturbance, while explicitly acknowledging data limitations. It provides essential data and theoretical support for the scientific management and targeted conservation of plateau urban wetlands.

Understanding large-scale geographical patterns of marine biodiversity and their underlying drivers remains a key objective in marine ecology. The marginal seas of the western Pacific, encompassing the world's most complex marine biogeographic transition zone and the biodiversity core of the Coral Triangle, offer an ideal system for studying global marine biodiversity dynamics. Here we surveyed fish diversity along a 4500 km transect from the Yellow Sea to the Java Sea by combining continuous ship-track seawater collection with environmental DNA (eDNA) metabarcoding. We detected 225 fish taxa, with members of the family Engraulidae both broadly distributed and numerically dominant, and we recorded four protected cartilaginous fishes. Compared with historical records, continuous ship-track eDNA sampling more effectively recovered planktivorous and upper-pelagic taxa that traditional gear typically underrepresents due to their mobility and low catchability. Importantly, fish diversity followed a distinct three-phase pattern along the transect, characterized by an initial increase from the Yellow Sea to the South China Shelf, a sharp decline toward the South China Sea Islands, and a gradual recovery approaching the Sunda Shelf. These shifts were consistently associated with abrupt geomorphological transitions along the continental shelf and with topographic variables such as bottom depth and coastal distance. This study highlights the transformative potential of eDNA for global-scale ocean monitoring and provides compelling evidence that topographic variables play a dominant role in shaping macro-scale marine biodiversity patterns in this region, surpassing the influence of other natural and anthropogenic factors.

Effective aquatic biomonitoring requires understanding how flow conditions influence the efficiency of environmental DNA (eDNA) sampling, particularly where conventional filtration is slow or impractical. Passive eDNA samplers (PEDS), which accumulate DNA on submerged substrates, offer a low-effort alternative, yet their performance across flow conditions remains poorly quantified. Guided by a flow-adsorption framework, we combined controlled flume experiments with field comparisons to test how flow affects passive eDNA capture. In flumes, glass fiber (GF) membranes accumulated eDNA rapidly and surpassed a 2 L filtration benchmark within 30 min at high velocity, as measured by droplet digital PCR. In field deployments across 21 lentic and lotic sites, metabarcoding showed that GF achieved the highest amplicon sequence variant (ASV) richness, outperforming filtration in running waters and equalling it in still waters. Together, these findings indicate that water movement enhances passive adsorption and that short immersions can suffice in swift rivers, whereas longer soaks are needed in lakes. GF-based PEDS are therefore a robust, low-effort, and scalable approach for standardized aquatic biodiversity monitoring, particularly in lotic systems.

Gymnodiptychus Herzenstein, 1892, a genus of the subfamily Schizopygopsinae, currently comprises three valid species: Gymnodiptychus dybowskii, Gymnodiptychus pachycheilus, and Gymnodiptychus integrigymnatus. Previous molecular phylogenetic studies have suggested that the genus is not monophyletic, but the taxonomic status of Gymnodiptychus integrigymnatus has not been comprehensively reassessed. In this study, we conducted an integrative taxonomic investigation of Gymnodiptychus based on mitochondrial genome data, combined with morphological and osteological evidence. Phylogenetic analyses using the concatenated sequences of 13 mitochondrial protein-coding genes and two ribosomal RNA genes recovered Gymnodiptychus as non-monophyletic. Gymnodiptychus dybowskii and Gymnodiptychus pachycheilus formed a monophyletic clade sister to Diptychus, whereas Gymnodiptychus integrigymnatus formed an independent lineage sister to Schizopygopsis. Genetic distance analyses further revealed substantial divergence between Gymnodiptychus integrigymnatus and other members of Gymnodiptychus. Morphological and osteological comparisons demonstrated that Gymnodiptychus integrigymnatus differs markedly from the other two species, Gymnodiptychus dybowskii and Gymnodiptychus pachycheilus, in lacking pectoral girdle scales, possessing extremely reduced maxillary barbels, having a terminal mouth, and lacking the supraorbital bone. Based on this combined evidence, we establish the new genus Gaoligongia gen. nov. for Gymnodiptychus integrigymnatus Mo, 1989, which is herein reassigned as Gaoligongia integrigymnata (Mo, 1989), comb. nov. We also provide a revised diagnosis of Gymnodiptychus and a key to the genera of Schizopygopsinae.

Aim: Phylogenetic diversity (PD) and phylogenetic endemism (PE) offer biogeographical and conservation insights beyond taxonomic approaches, yet their environmental associations in freshwater ecosystems remain unclear. Using freshwater fish, we mapped PD and PE patterns, identified their environmental correlates, and compared them with taxonomic metrics (species richness [SR], weighted endemism [WE]), while assessing conservation gaps. Location: Qinghai-Tibetan Plateau (QTP) and surrounding regions. Time period: Mid-Pliocene to present. Major taxa studied: Schizothoracine fishes. Methods: We compiled species distribution and reconstructed a molecular-based phylogeny. PD, PE, SR, and WE were quantified at the subdrainage scale. Phylogenetic hotspots were categorised as 'cradles' (neo-endemism) or 'museums' (paleo-endemism). Linear mixed-effects models evaluated environmental correlates (climate, hydrology, topography, and geology). Hotspot overlap with protected areas was assessed. Results: Subdrainages exhibiting high values for both phylogenetic and taxonomic metrics were predominantly distributed along the southern margin of the QTP, particularly in the Hindu Kush-Himalaya-Hengduan mountains, yet showed substantial spatial incongruence between metrics (SR vs. PD: r = 0.67, p < 0.001; WE vs. PE: r = 0.29, p < 0.001). Both hotspot types were concentrated in these high-value subdrainages, covering 13.36% (phylogenetic) and 11.96% (taxonomic) of the study area, with limited spatial overlap (Jaccard index = 0.18). Notably, 65.89% of 'cradles' and 'museums' exhibited co-occurrence. Although most environmental factors, dominated by temperatures (annual mean and seasonality), showed generally consistent associations with both phylogenetic and taxonomic metrics, their contributions varied considerably. Conservation coverage remained inadequate for both hotspots (phylogenetic: 27.43%; taxonomic: 31.89%). Main Conclusions: We highlight substantial incongruence between phylogenetic and taxonomic diversity patterns and their environmental correlates in freshwater fishes. Our drainage-scale framework provides a template for analyzing freshwater phylogenetic diversity metrics, complementing taxonomic diversity in conservation planning, as protecting both is essential for maintaining ecosystem adaptive capacity under anthropogenic pressures.

Abstract Global warming–driven temperature changes pose a major threat to aquatic animal health and growth, with the gut microbiota playing a key role in thermal tolerance. However, responses to low and high temperatures (HTs) are rarely compared within the same system. Here, we combined 16S rRNA sequencing and ultra-high performance liquid chromatography (UHPLC)-based metabolomics to examine physiological responses in captive Yangtze finless porpoises (YFPs) under different temperature conditions. Marked shifts in gut microbial composition and metabolic profiles were observed. At the phylum level, Firmicutes increased under low temperature (LT), Proteobacteria and Fusobacteriota under HT, and Actinobacteria and Cyanobacteria under control temperature (CT). At the genus level, Romboutsia and Terrisporobacter were enriched in HT, Paeniclostridium in LT, and Patescibacteria in CT. Metabolite analysis revealed clear temperature-specific patterns, with remikiren, hydratopyrrhoxanthinol, and lyciumoside VIII elevated in HT; taurocholic acid, 8-oxoguanosine, and leptomycin B in LT; and L-carnitine and lysylvaline in CT. Most differential metabolites were associated with amino acid metabolism, protein digestion and absorption, and lipid metabolism pathways. Significant correlations between gut microbiota and metabolites were identified. Together, these findings show that temperature strongly shapes the gut microbiome and metabolome of YFPs, providing new insights into their metabolic adaptation and stress responses to environmental change.

Aim To propose and validate a novel integrated framework for the verification and delimitation of cryptic species in widely distributed, morphologically conservative taxa, using the cosmopolitan oligochaete Lumbriculus variegatus as a model system. This framework moves beyond single-source data by synergistically combining molecular phylogenetics, ecological niche characterisation, historical biogeographic reconstruction and cytogenetic evidence to provide robust, multi-dimensional validation of evolutionary lineages and their divergence mechanisms. Location Global dataset of 2595 filtered occurrence points with additional sampling across China. Taxon Lumbriculus variegatus (Annelida Clitellata). Methods We developed a 'phylogeny-niche modelling' workflow. (1) Putative evolutionary lineages were first delineated using mitochondrial COI sequences via phylogenetic analysis, haplotype networking and genetic distance calculation. (2) An environmental discriminant model, based on bioclimatic and elevation data from genetically identified samples, was built to ecologically classify all occurrence records into these lineages. (3) For each lineage, optimised MaxEnt ecological niche models were constructed and projected onto the Last Glacial Maximum, the Mid-Holocene and the current climates to reconstruct historical distribution dynamics. Niche breadth and overlap were quantified. (4) Genome size estimates from flow cytometry and genome surveys provided independent cytogenetic validation of lineage divergence. Results The framework robustly identified two deeply divergent, evolutionarily independent lineages (CI and CII) within L. variegatus. Their inter-lineage genetic distance (0.158) exceeded conservative species-level thresholds. While showing complex transcontinental sympatry, the lineages exhibited significant ecological niche differentiation: CI occupies warm-humid niche, whereas CII has a broader niche adapted to cooler, circumpolar and high-altitude regions. Historical projections revealed distinct glacial refugia and postglacial expansion pathways. Crucially, a nearly ninefold difference in genome size provided strong independent support for their distinct evolutionary status. From the Last Glacial Maximum to present, niche overlap decreased while geographical overlap increased, indicating niche divergence alongside range expansion. Main Conclusions The study successfully presents and validates a powerful, reproducible framework that integrates phylogenetic, ecological, historical and genomic evidence to resolve cryptic diversity. The application to L. variegatus confirms its efficacy, revealing at least two independent species maintained by ecological niche divergence and major genomic reorganisation. This integrated approach overcomes the limitations of single-method analyses and provides a generalizable pipeline for species delimitation in taxonomically challenging groups with high cryptic diversity and low dispersal capacity.

Two new species of the genus Sineuchiloglanis are described from two tributaries of the upper Yangtze River, China. These two new species can be distinguished from all congeners by morphological comparisons and phylogenetic analysis. Sineuchiloglanis chishuiensis sp. nov. can be distinguished from its congeners by the combination of the following characters: eye enlarged, with diameter 6.8–9.1% of head length (HL); interorbital width 24.1–24.8% of HL; maxillary barbel length 67.1–84.4% of HL; caudal-peduncle depth 27.1–40.3% of caudal-peduncle length; dorsal-fin rays i, 51/2; anal-fin rays i, 41/2; caudal-fin rays i, 7+8, i; gill opening extending to the base of second to third pectoral-fin elements; tip of nasal barbel not reaching anterior orbital margin; pelvic-fin tip reaching or extending beyond anus; and the abdomen slightly convex in profile. Sineuchiloglanis baishuiensis sp. nov. can be distinguished from its congeners by the combination of the following characters: head depth 42–48.4% of HL; maxillary barbel length 65.9–82.1% of HL; caudal-peduncle depth 25.9–40.6% of caudal-peduncle length; dorsal-fin rays i, 51/2; anal-fin rays i, 41/2; caudal-fin rays i, 7+8, i; gill opening extending to the base of the fourth to fifth pectoral-fin elements; tip of maxillary barbel not reaching the lower corner of the gill opening; tip of nasal barbel not reaching anterior orbital margin; and the abdomen flattened in profile. Molecular phylogenetic analysis inferred from mitochondrial Cytb gene sequences supported the validity of these two new species.

The Yangtze finless porpoise (YFP) is a critically endangered freshwater cetacean endemic to China. Understanding seasonal breeding patterns is critical for the effective conservation of critically endangered species. The current study was designed to examine the function and taxonomic characteristics of fecal microbiota and their metabolites in male captive YFPs during both nonbreeding (NB) and breeding (B) seasons, analyzing 20 fecal samples using both UHPLC-MS/MS and 16S rRNA gene sequencing approaches. The present study revealed that Firmicutes were increased in the NB season, while Actinobacteria, Proteobacteria, and Fusobacteriota were increased in the B season at the phylum level. At the genus level, Paeniclostridium, Clostridium_sensu_stricto_13, and Mycobacterium were increased in the NB season, while Romboutsia, Plesiomonas, and Cetobacterium were increased in the B season. LEfSe analysis revealed that Staphylococcus, Comamonas, and Tetrasphaera were significantly increased in the B season, while the genus Terrisporobacter was substantially increased in the NB season. The fecal metabolome undergoes significant changes during the B and NB seasons, altering metabolic pathways such as phenylalanine metabolism, protein digestion, taurine and hypotaurine metabolism, lysine degradation, tryptophan biosynthesis, tyrosine metabolism, and bile secretion. Moreover, there was a significant correlation between the fecal metabolome and microbiome in the captive YFPs in the B and NB seasons. This study explores the impact of seasonal reproduction on gut microbes and their metabolites, providing insights into animal seasonal reproductive behavior and providing a theoretical basis for studying gut microbiota and metabolites in cetaceans, both in captivity and in the wild.

The first obligatory troglobitic Claea species, Claea scet, is described from a subterranean river in a cave connected to the Yangtze River in Hulu Town, Shawan District, Leshan City, Sichuan Province, southern China. C. scet differs from all congeners by the following combination of characters: Body pale without pigmentation; eye vestigial, diameter of eye 3.8–5.9% SL; short anal fin, anal fin height 7.0–8.4% SL. Molecular phylogenetic analysis supported the validity of the new species and revealed a close relationship between Claea and hypogean Triplophysa species.

Amur minnow, Rhynchocypris lagowskii (Dybowski, 1869), is a small omnivore cyprinid and native from Lena River in the north to the Yangtze River in the south. In August 2022, we first caught this species in Duobu Reservoir in the Niyang River, a tributary of middle reaches Yarlung Tsangpo River in Xizang, China. Thereafter, more and more individuals (adults and juveniles) of this species were caught in the middle reaches of Yarlung Tsangpo River. The annual variation of gonosomatic index and body length distribution of two years fully confirmed that the species has successfully established populations and dispersed in the Yalung Tsangpo River. This study documents one of the fastest freshwater fish successful invasions recorded in China, as evidenced by the establishment of large wild populations and rapid range expansion within just one year of initial introduction. The rapid range expand of Amur minnow in the Yarlung Tsangpo River is primarily attributable to multiple human-mediated introduction events (religious release) at various locations. As an omnivore and cold-adapted cyprinid with similar diet of native, Amur minnow has potential significant impact to native fishes and biodiversity.

Human-induced environmental changes increase species turnover, typically characterized by native species extirpation and non-native species (NNS) invasions, leading to multiple functional consequences owing to varying species roles and whether losses from extirpation are compensated by newly established NNS. We analysed community functional roles among fish species that persisted, were extirpated or were newly established over 75 years (1940-2015) in 15 lakes in southwest China, using functional diversity indices and trait-based network analyses. While species extirpation rate increased strongly through time, earlier extirpations caused the greatest losses to novel functional diversity. Functional losses from native species extirpation were not compensated by NNS. Functional patterns of extirpations were mainly random or overdispersed, whereas invasions were almost always random species replacements. Synthesis and applications. Our findings highlight that the loss of distinctive functional diversity persists even when extirpation rates are low, due to the incomplete functional replacement of native species by NNS, which are typically functionally random relative to extirpated species. This underscores the importance of prioritizing the protection of functionally distinct species to preserve community integrity. Additionally, our use of trait-based network analysis provides a novel perspective for understanding the functional implications of species turnover, and could be a valuable tool for researchers and conservation practitioners to evaluate community assembly processes and functional structure dynamics.

Factors like sex, diet changes, hormone levels, and stressors disrupt animals' symbiotic bacterial communities. Maintaining healthy bacterial communities is particularly challenging for social species, as group membership, social relationships, microbial transfer, and social stressors influence their microbiotas. This study investigated the influence of sex and social dynamics on the gut microbiome and associated metabolites in the captive Yangtze finless porpoise (YFP), employing 16S rRNA gene sequencing and ultra-high-performance liquid chromatography with tandem mass spectrometry-based metabolomic analyses. The present study reveals that sex and social grouping, that is, male-male (MM), female-female (FF), and male-female (MF) groups, significantly influence the alpha and beta diversity in the captive YFP. The phylum Firmicutes were increased considerably in the FF social group, while Proteobacteria, Cyanobacteria, and Fusobacteriota were significantly increased in the MM group, while Desulfobacterota were risen considerably in the MF group. The genera Macrococcus, Clostridium_sensu_stricto_13, and Cetobacterium were considerably raised in the MM group, Paeniclostridium and Turicibacter were substantially raised in the FF group, while the genus Peptostreptococcaceae were substantially raised in the MF group. The current research also presented significant metabolite variations in the sex and social groups which significantly altered the metabolic pathways such as bile secretion, glycerophospholipid metabolism, protein digestion and absorption, citrate cycle, and carbohydrate digestion in the captive YFPs. Additionally, the research identified a significant correlation between the gut microbiome and fecal metabolome across different sex and social groups. In conclusion, this research highlights the connection between changes in fecal microbiota and host metabolism in captive YFP. It shows how sex and social group dynamics affect both metabolic and bacterial variations, offering valuable insights for improving health and social welfare management in captive YFPs.

The gut microbiota can act as a buffer against changes in energy and food availability and adapt plastically to fluctuations in the host’s diet. However, it is unknown how changes in the gut microbiome with the seasons impact microbial metabolism and the accessibility of nutrients to hosts. The study utilized 16S rRNA and UHPLC-MS/MS approaches to examine seasonal fecal metabolome variations in the captive Yangtze finless porpoises (YFPs) to determine if these variations are linked to nutrient intake or gut microbiome composition changes. The YFPs were mostly fed a frozen and live fish diet, with different food intakes yearly. We found that gut microbial diversity remained constant, but community structure varied seasonally. Firmicutes and Cyanobacteria were higher in winter, Actinobacteria in spring and fall, and proteobacteria in summer. The genus Paeniclostridium was significantly higher in the spring season, Romboutsia and Clostridium_sensu_stricto_13 were significantly higher in the summer, while Terrisporobacter and Macrococcus were significantly higher in the fall group. The study reported that seasonal dietary variation significantly impacted the fecal metabolome by affecting the metabolism, including energy, amino acid, carbohydrate, and nucleotide metabolism of the captive YFP. Moreover, significant correlations between metabolome and microbiome were found, and these correlations may indicate that the captive YFP has adapted to cope with dietary variations and enhance energy acquisition. These findings improve our knowledge of the link between microbiota, diet, metabolites, and the physiology of the host and suggest that gut microbial populations may adapt continuously to changes in diet.

The Yangtze finless porpoise (YFP), a critically endangered small odontocete species, is mostly living in the lower and middle sections of the Yangtze River and its two big adjacent lakes. The YFP population experienced a drastic decline due to the threats from various human activities. Comprehending their biology, particularly the immune changes associated with aging, is essential for ensuring their protection. The study aimed to identify genes and pathways in thirteen YFPs blood that are influenced by age, revealing their immune system’s susceptibility to aging and reduced disease response. The current research utilized RNA-Seq to find differentially expressed genes (DEGs) in blood tissues, and we screened 478, 442, and 739 DEGs in comparison groups of calf vs. adult, calf vs. old, and adult vs. old, respectively. STEM, GO and KEGG enrichment analyses revealed significant changes in metabolism, immune-related, development, signal transduction pathways, and aging among the three age-related groups. In the calf vs. adult group, the DEGs were mainly associated with primary immunodeficiency, IgA production, and B cell receptor signaling pathways. In the calf vs. old group, the DEGs were significantly enriched in autoimmune disease, cytokine interactions, and viral/bacterial infections. In the adult vs. old group, the DEGs were primarily linked to cytokine interactions and bile secretion. The current study identifies DEGs affecting immunity, development, and growth in YFPs by comparing blood transcriptomes of calves, adults, and old YFPs. This information provides a basis for studying YFP’s development, growth, and aging and will guide future research on disease prevention, treatment strategies, management, and conservation of YFP.

Biological invasions threaten both biodiversity and ecosystem functioning, yet the role of functional and phylogenetic relationships between invaders and the recipient community in invasion success remains controversial. Two competing hypotheses-Darwin's naturalization hypothesis (DNH) and the preadaptation hypothesis (PAH)-offer contrasting predictions about whether invaders succeed by differing from or closely resembling the resident community. Empirical evidence indicates that support for these hypotheses is highly context-dependent. We addressed four key hypotheses in fish communities in 15 lakes in south-western China over a 75-year period (1940-2015), divided into three intervals. First, we examined whether interpretations of Darwin's naturalization conundrum varied with species turnover, quantified by the loss of community integrity (LoI)-defined as the proportional decline of native species due to extirpations and establishments of non-native species (NNS). Second, we employed a functional-trait-based network analysis to determine whether insights at the functional-group scale offer clearer explanations of invasion patterns than those at a community scale. Additionally, we analysed the temporal patterns of species turnover to test whether they align with the 'rich-get-richer' or 'biotic resistance' hypotheses. Our results revealed that the PAH was supported in early stages of community turnover, though support changed to DNH as LoI increased. Network analyses at the functional-group scale clarified these dynamic shifts, demonstrating that established NNS progressively occupied central roles within functional groups and increased overall differentiation among groups. Thus, trait-based network analyses provided deeper insights compared with community-scale analyses alone. The initial pattern of species turnover supported the 'rich-get-richer' hypothesis at both lake and functional-group scales, with species-rich communities experiencing higher numbers of invaders during the 1940s-1970s. Conversely, this pattern reversed over time, as the number of invaders between 1985 and 2015 was inversely related to resident species richness. By integrating traditional phylogenetic and functional distance analyses with novel functional-trait-based network approaches, our study highlights the context-dependent nature of invasion success. This integrative framework advances our understanding of community assembly processes.

The evolution of paleo-drainages on the Qinghai-Tibet Plateau is significant for understanding the paleogeographic, topographic, and the orogenic exhumation history. Fossils of freshwater fishes are helpful for understanding the biological and geological interplays in the ecosystem because they are usually restricted to the drainages, which are in turn constrained by tectonic events. This study re-examines Plesioschizothorax macrocephalus, a fossil cyprinid fish from the Lower Miocene of the Lunpola Basin in the 1970's. Our updated phylogenetic analysis based on total-evidence dating suggests that Plesioschizothorax is most closely related to extant Percocypris, a genus currently found in the Mekong, Salween, and Upper Yangtze Rivers. Their evolutionary split, estimated to have occurred in the Late Oligocene (ca. 26.60 Ma), coincides with the intensification of Asian monsoon in the central Qinghai-Tibet Plateau. Our ancestral distribution reconstructions indicate that the common ancestor of these two fishes likely inhabited the central Qinghai-Tibet Plateau. During the Late Oligocene (26.60 Ma) to Early Miocene (21.63 Ma), their descendants dispersed to the paleo-Mekong and Salween Rivers. We assume that the enhanced precipitation due to the strengthening of the Asian monsoon had led to an expansion of the upper paleo-Mekong and Salween Rivers during the Late Oligocene to Early Miocene, creating a hydrological connection with the paleo-lakes in the Lunpola Basin and thereby providing pathways for dispersal. This scenario implies that the current internal drainage systems in the central plateau likely formed after the Early Miocene.