摘要: A list of coral reef fish species of Huaguang Reef was compiled in 2023 using hand fishing, diving fishing, underwater video, and eDNA detection, combined with historical data from 1979 and archival records from the South China Sea Fisheries Research Institute of the Chinese Academy of Fisheries Sciences for the years of 1998, 1999, 2003, and 2005. Successional characteristics of coral reef fishes through time were also explored. The findings revealed: (1) A total of 299 coral reef fish species were identified in Huaguang Reef, categorized into 2 classes, 16 orders, and 56 families, with Perciformes exhibiting the highest species count (234), constituting 78.26% of all species. (2) In comparison to the period of 1979-2005, there was a reduction in the number of species at the order and family levels in 2023 at Huaguang Reef. Both the average taxonomic distinctness (Delta+) and the variation in taxonomic distinctness (Lambda+) exhibited a declining trend, indicating disturbances in the fish ecosystem. (3) The proportion of herbivorous fish at Huaguang Reef remained relatively stable in 2023 compared to the 1979-2005 period. Notably, the similarity coefficient of herbivorous fish was the highest among different feeding types, signifying a degraded state of the Huaguang Reef habitat. (4) In contrast to the 1979-2005 period, a significant decline was observed in large-sized and carnivorous fish species at Huaguang Reef in 2023. The low similarity coefficients for both categories, with undiscovered fish species accounting for 58.49% and 45.76% of their respective taxa in the total list, respectively, suggested a notable impact of overfishing on coral reef fishes. The succession patterns revealed in this study provide a theoretical foundation for advancing the sustainable development of coral reef fish resources in the Xisha Islands and offer valuable insights for the protection and management of coral reef fishes.

摘要: Aquatic environments expose fishes to a wide range of pathogens, emphasizing the crucial role of their immune system. Chemokines are key mediators that bridge innate and adaptive immunity by regulating immune cell activity. As essential components of immune defense, immune cells play a central role in recognizing and eliminating pathogens. In mammals, chemokines exhibit direct antimicrobial activity and can enhance vaccine efficacy as molecular adjuvants. However, these functions remain insufficiently explored and summarized in teleost fishes, limiting their practical use in aquaculture. Given the evolutionary conservation of immune systems and chemokine families between teleost fishes and mammals, it is likely that chemokines have conserved functions across these vertebrates. This review systematically examines the roles of chemokines in regulating the functions of immune cells (macrophages, neutrophils, T cells, and B cells) in teleost fishes, and explores their potential application as direct antimicrobial agents and vaccine adjuvants in aquaculture, thereby providing a theoretical foundation for the prevention and control of aquatic diseases.

摘要: Micro-eukaryotic communities are highly sensitive to environmental changes, and their structure offers crucial insights into the impact of human activities on aquatic habitats. Despite their significance, the assembly mechanisms of micro-eukaryotic communities in lake ecosystems heavily influenced by human activities are not well understood. In this study, we utilized 18S rDNA amplicon sequencing to examine the biodiversity of microeukaryotes over a one-year period in Lake Weishan, one of the largest freshwater lakes in northern China. We analyzed the ecological processes governing community assembly among key ecological groups, specifically habitat generalists and specialists. Our findings revealed substantial temporal variation in microbial diversity and community composition, likely driven by water temperature, dissolved oxygen, and the concentrations of several ions (e.g., Ca2+ and F-). Notably, community assembly in this canal-disturbed lake was predominantly influenced by stochastic processes (58.18%) rather than deterministic processes (20.46%). Habitat specialists (425 operational taxonomic units, OTUs) exhibited significantly greater diversity compared to habitat generalists (189 OTUs) and were predominantly shaped by stochastic processes (52.47%). In contrast, habitat generalists were less influenced by these processes (17.69%). Altogether, these results suggest that the ecological processes governing micro-eukaryotic community assembly differ markedly between habitat generalists and specialists, primarily due to their varied adaptability to environmental changes.

摘要: The glaciers on the Tibetan Plateau are important climate regulators and recharge sources for many rivers and lakes, which are of great ecological value. However, actions to protect glacier-associated habitats are urgent, as human activities have led to increased glacier retreat and may have an impact on climate and downstream environmental balance. Glaciers contain a variety of habitats (ice, snow, cryoconite, deglaciated soil, etc.) that harbor rich microbial communities (the main bearers of glacial life activities). To provide scientific support for the development of glacier protection strategies on the Tibetan Plateau from a microbial perspective, this review reveals the interactions between glacial microorganisms and glacial ecosystems on the Tibetan Plateau. In addition to describing the origin, diversity, adaptability and biogeochemical cycles of microorganisms, we emphasized the roles of environmental pollutants and climate change. It has been shown that exogenous microorganisms can be deposited on the glacier by atmospheric circulation. The special geo-climatic characteristics of glaciers may have prompted these microorganisms to adapt to this extreme environment through evolution and cooperation. These microorganisms are involved in the cycling of biogenic elements in glaciers, providing feedback to the Earth's ecosystem. However, increased environmental pollution may affect the glacier microorganisms. Some pollutants synergize with climate warming to accelerate glacial melting, with meltwater carrying microorganisms, nutrients, and pollutants into downstream ecosystems, which may have far-reaching impacts on downstream ecosystems and the global climate. Reducing source pollution, strengthening international cooperation, implementing long-term monitoring, developing predictive models, and tapping into special microorganisms are the way forward in guarding the clean land of the Tibetan Plateau glaciers in the future.

摘要: Nature reserves in the Yangtze River, China, are crucial for protecting the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) and their habitats. Despite a 10-year fishing ban along the middle and lower reaches of the Yangtze River instated on January 2020 to alleviate pressures on the porpoise's prey, other stressors, particularly underwater noise, continue to impact these rare cetaceans, which rely heavily on vocalization for prey detection, communication and navigation. Between September 2020 and September 2021, underwater noise monitoring was carried out in the Xinluo Baiji National Nature Reserve, located in Hubei province, China, with the aim of assessing the potential impact of underwater noise pollution on the Yangtze finless porpoise. The reserve was divided into 30 sub-sections to systematically monitor underwater noise across the reserve. Passive acoustic monitoring was conducted at each site within these sub-sections during four sampling periods, and these data were subjected to comparative analysis with data collected in 2012 and 2017. The results showed that the root mean square sound pressure levels at each site ranged from 117 to 162 dB. Power spectral levels (11.2-152 kHz) exceeded the average audiogram levels for the porpoise at most sites. 94.2% and 93.3% of the sites exceeded underwater acoustic thresholds known to induce a hearing threshold shift for the porpoise in terms of both the averaged cumulative unweighted sound exposure level, and cumulative weighted sound exposure level respectively. Noise levels in this section during 2020-2021 were approximately 25 and 30 dB higher compared to the levels recorded in 2012 and 2017, and likely due to increased shipping activity and the proximity of sampling sites to the shipping channel. The rise in noise levels might contribute to the observed declines in the porpoise population within this area. To mitigate these impacts, implementing noise control measures is essential, such as regulating navigation speed and limiting the number of vessels in the reserve.

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摘要: Grass carp reovirus (GCRV)-induced gene 1 (Gig1) is identified initially in crucian carp C. auratus as a novel interferon-stimulated gene (ISG) encoding an antiviral protein and subsequently as the founder member of Gig1 gene family. However, the evolution and function of Gig1 family members remain largely unknown. In this study, genome-wide searchs of 100 vertebrate species representing the main taxonomic lineages revealed that the Gig1 family originated from a common ancestor of bony fish but was completely lost in tetrapods. The Gig1 family is divided into three subfamilies, each with its own characteristics in gain and loss. Compared to subfamily I that originated the earliest and showed no significant change in gene copies, subfamilies II and III were expanded robustly with teleost radiation. Despite no known domains having been identified, motif prediction revealed a conserved motif arrangement in all Gig1 family proteins. Functionally, both zebrafish and grass carp have subfamilies I and II but not subfamily III. However, only certain subfamily II genes were highly induced by viral infection and thus capable of inhibiting viral replication by overexpression and knockout assays. The Japanese rice fish medaka has no subfamily II and, strikingly, one subfamily III gene acquired antiviral feature. Site-directed mutation showed that three leucine residues conserved in the motif 1 were essential for the antiviral role of subfamily II genes in zebrafish. In summary, our results indicate that bony fish-specific Gig1 gene family has been undergoing diversification in expression and function toward virus infection in a given species.

摘要: Springs are essential for water security in the Cerrado (Neotropical Savanna Biome), especially considering its prolonged dry periods. However, the protection of these environments is often compromised by various human activities, necessitating the creation of plans for protecting and rehabilitating already degraded springs. Thus, assessing the environmental condition of springs is essential for adopting effective protection or rehabilitation measures. Therefore, the aim of this study is to apply protocols for assessing spring environmental conditions in the Cerrado. To achieve this, we conducted a literature review of existing environmental protocol models, adapted them after considering Cerrado environmental conditions, and field-tested a protocol termed the Spring Condition Index (SCI). We used linear models to measure the relationship between SCI scores and physical-chemical variables of water and local vegetation. We assessed a total of 41 springs, and SCI values ranged from 0.61 to 0.94, where values closer to 1 indicated a more preserved spring. SCI showed a positive linear relationship with dissolved oxygen and landscape vegetation cover, and a negative linear relationship with water temperature, pH, and electrical conductivity. Despite a macroscopic analysis, these results indicate that SCI is effective and robust for measuring spring environmental condition, with the advantage of being conducted in just a few minutes. Thus, we suggest its application throughout the biome so that springs with lower SCI values can be quickly identified and prioritized for rehabilitation in the Cerrado Biome.

摘要: The Insulin-like Growth Factor Binding Protein (IGFBP) family genes, which function as carrier proteins in the circulation, are integral to various physiological processes such as growth, metabolism, reproduction, and stress responses. However, the systematic identification, characterization, and functional analysis of igfbp family genes in teleosts remain to be explored. In this study, we identified and characterized a total of 11 IGFBP family members in the Leopard Coral Grouper (Plectropomus leopardus). Expression analysis revealed that igfbp genes exhibit tissue-specific expression patterns in adult P. leopardus. Notably, certain igfbp genes were differentially expressed in growth-related tissues in fast-growing versus slow-growing individuals, suggesting their potential role in growth regulation. Specifically, the expression of igfbp2a and igfbp2b in the liver was further validated using FISH. Furthermore, knockdown of igfbp2b expressed specifically in the liver resulted in the promotion of muscle development and increased expressions related to muscle cell development. Additionally, several igfbp genes were dynamically involved in the response to acute hypothermia in the brain, gills, kidneys, and liver. These findings offer a comprehensive understanding of the characteristics and functions of igfbp family genes in P. leopardus, providing a solid foundation for further investigation into the functional mechanisms of igfbp genes in teleosts.

摘要: Fish, which are vital for both aquatic ecosystem functionality and global food supply, rely heavily on their gastrointestinal tract (GIT) microbiota for the digestion that underpins their growth and health. Takifugu pufferfish, which are an example of species evolved through adaptive radiation, possess a GIT that is specialized for antipredator defense and gluttonous feeding behaviors, offering a unique model to explore the effects of GIT compartmentalization and host genetics on gut microbial communities. Here we compiled 78 full and partiallength 16 S rRNA amplicon datasets across three anteroposteriorly distinct intestinal sites in a cohort of cohabitating artificial hybrid and purebred Takifugu pufferfishes. Our findings reveal a compositional and functional biogeography of pufferfish gut microbiota along the GIT and between host genetics. Additionally, the differential abundance of specific amplicon sequence variants and their correlation with host genetic backgrounds and intestinal sections highlight the role of environmental filtering in shaping microbial communities, with certain bacterial taxa exhibiting strong preferences for particular intestinal sites or genetic backgrounds, suggesting potential localized adaptation or functional specialization. This study enhances our understanding of the intricate interplay between host genetics, gut anatomy, and microbiota in fish, underscoring the importance of detailed microbial profiling in conservation efforts and aquaculture practices, and emphasizing the necessity of integrating full-length 16 S rRNA sequencing with partial-length datasets to comprehensively understand microbial diversity and function, paving the way for improved fish health management and sustainable aquaculture strategies.