摘要: Lotic ecosystems are especially vulnerable to the adverse effects of urbanization because of their close connectivity with the surrounding terrestrial ecosystems. There is, however, a knowledge gap in how the taxa and functions of benthic macroinvertebrate assemblages respond to a gradient of urban land use and where their tipping points are along this gradient. Thus, we quantified how urban land use in stream catchments influenced benthic macroinvertebrate assemblages functionally and taxonomically. We found that urbanization affected benthic macroinvertebrate assemblage taxa and functions at tipping points of <10% of stream catchment urbanization. Greener human settlements are needed to minimize losses of sensitive macroinvertebrate taxa and their functions.

摘要: Atlantic cod, Gadus morhua, is a marine fish, but there are several Arctic lakes, where it also occurs. Mogilnoye Lake on Kildin Island in the Barents Sea is especially famous for them. It is a salinity stratified meromictic lake. The surface layer is fresh with saline water saturated with hydrogen sulfide underneath. Kildin cod have been studied over the last 100 years with emphasis on taxonomy, physiology, genetics and growth. However, the conservation of this species has been overlooked. Recent sonar surveys showed that the cod are quite abundant, but in danger from hydrogen sulfide accumulation within the lower lake levels. Therefore, the habitat of this species is shrinking. Conservation studies must be a priority in the situations like this.

摘要: Planktonic microorganisms have been recognized as important components in biogeochemical cycling in lakes. However, research into the impact of phyllosphere microorganisms, particularly those involved in carbon cycling, on CO2 fluxes in macrophyte-dominated lakes within the context of global environmental changes remains scarce. Here, by employing high-throughput sequencing techniques, we experimentally tested how nutrient enrichment, top-down effects of fish and increases in dissolved organic carbon (DOC) affect CO2 exchange flux at the water-air interface by altering the community structure and functioning of phyllosphere bacteria on macrophytes. We found that our mesocosm ecosystems exhibited a net absorption of CO2, but nutrient enrichment significantly decreased the absorption ability. Mantel tests and multiple regression modeling also showed that eutrophication-associated parameters (total nitrogen, total phosphorus and ammonium nitrogen), pH, and extinction coefficient were the key drivers influencing abundance of phyllosphere functional microorganisms. In addition, these experimental treatments significantly altered the composition, diversity and co-occurrence networks of carbon cycling- associated phyllosphere microorganisms, which impacted the CO2 flux. Structural equation models and linear regression further showed that the Shannon Index of phyllosphere functional microorganisms related to carbon cycling (rather than plant volume inhabited- PVI) had a significant positive impact on CO2 fixation. This means that environmental changes-especially eutrophication-may hinder carbon sequestration by decreasing the diversity of phyllosphere microorganisms rather than reducing the abundance of submerged macrophytes. This study increases our understanding of carbon cycling processes in aquatic environments from a management perspective by emphasizing the importance of protecting the diversity of phyllosphere microorganisms in macrophyte-dominated lakes.

摘要: The hadal zone environment, characterized by extreme hydrostatic pressure, low temperatures, and limited food availability, presents substantial survival challenges for deep-sea fish species. In this study, we captured five deepsea fish species (Bathysaurus mollis, Coryphaenoides rudis, Ilyophis sp., I. brunneus and Pseudoliparis swirei) from the Mariana Trench at depths ranging from 2027 to 7125 m, by employing China's Exploration I and Exploration II. By combining lipidomic and proteomic analyses, we aimed to explore the genetic basis of adaptive evolution to the hadal zone in fish. The results indicate several key findings: (1) P. swirei (Mariana hadal snailfish, MHS) may enhance energy storage and utilization during prolonged fasting periods by significantly increasing liver tissue levels of cholesterol ester (CE), ether-linked triacylglycerol (TG-O), coenzyme Q (CoQ), and ATPase content; (2) MHS could maintain membrane fluidity under high pressure by increasing the proportion of unsaturated fatty acids while reducing levels of cholesterol and phosphatidylethanolamine (PE) content. (3) The regulation of lipid types and ratios could increase the risk of lipid peroxidation. To counter oxidative stress, MHS likely elevates monounsaturated fatty acid content and enhances antioxidants such as transferrin and heat shock proteins. Overall, this study provides new insights into the adaptive mechanisms of MHS to deep-sea conditions through the lipidome and proteome analyses, thus broadening our understanding of its resilience in the hadal zone.

摘要: Half-smooth tongue sole (Cynoglossus semilaevis) is regarded as a significant commercial marine fish species in China, and frequent outbreaks of vibriosis has led to substantial economic losses. In this study, we investigated the molecular mechanisms underlying the involvement of the extracellular matrix (ECM) signaling pathway in the skin immune response of C. semilaevis infected with Vibrio vulnificus. The results showed that most differentially expressed proteins (DEPs) were identified through iTRAQ proteome analysis, and ten ECM-related proteins were screened at 12 and 36 h post-infection (hpi). Notably, several DEPs associated with ECM including HSPG, FN, COCH, LAMB1, LAMC1, TSPN, COL6A1, AMBP, HX and ITGA6 were tested for their expression at the transcriptional level during V. vulnificus infection using qRT-PCR assay. The analysis of protein-protein interaction (PPI) showed that the integrin ITGA6 exhibited obvious interactions among ECM-related DEPs. Furthermore, the spatio-temporal expression of the Csitga6 gene was highest in the skin, gill, muscle, and spleen, but lower in the liver, kidney and intestine. To our knowledge, this is the first report on the involvement of ECM pathway in the skin immune response to V. vulnificus infection, and provides a reference for further study of the ECM mechanism in the mucosal immune response of marine fish.

摘要: In the 1930s, plastic items started to acquire popularity. Since then, they have overcome many barriers and are now important to many facets of society. Post-consumer plastic, however, is an environmental problem of increasing concern. Marine and freshwater environments are being impaired by plastic pollution, which is mostly the result of improper post-use plastic disposal. Herein I review recent literature on plastic effects to marine and freshwater environments, based on a Scopus search. Authors' keywords were analyzed and mapped. Results depicted microplastics as a global concern for the environment, animals, and human health, and was identified as a primary research focus and emerging topic concerning plastic effects on marine and freshwater environments. The foremost research gap is the lack of clear connections between the effects of plastic on human health, animal health, and the environment. Water pollution and its consequences on marine and freshwater environments are attributed primarily to human activity.

摘要: Large pelagic predatory fishes play an important role in marine ecosystems, occupying the highest position in food webs and accumulating energy and organic matter produced by aquatic organisms of lower trophic levels. Among pelagic predatory fishes, more attention has been given to the sharks, tunas and billfishes inhabiting equatorial and tropical waters, whereas pelagic predatory fishes inhabiting subarctic and temperate waters have been much less studied. We analyzed long-term midwater trawl survey data to investigate changes in the spatial distribution, ranges, and catch rates of the three most abundant large predatory teleosts in the Russian and adjacent waters of the northwestern Pacific, namely, the North Pacific daggertooth Anotopterus nikparini, the longnose lancetfish Alepisaurus ferox, and the Pacific pomfret Brama japonica. The northernmost distributions of daggertooth, lancetfish, and pomfret were observed in summer, spring, and autumn, respectively. All three species were characterized by the greatest northwards occurrence in the 2000s. In the study area, their maximum frequency of occurrence was recorded during the summer, and they were most frequently caught in the 1980s (lancetfish and pomfret) and 1990s (daggertooth). The average catch rates of daggertooth and pomfret were highest in summer, whereas those of lancetfish were highest in winter. The highest average catch rates of daggertooth, lancetfish, and pomfret were recorded in the 2000s, 1990s, and 1980s, respectively. The maximum absolute catch rates of lancetfish were recorded in winter, whereas those of daggertooth and pomfret were recorded in spring and summer, respectively. The maximum absolute catch rates of daggertooth and pomfret were observed in the 1980s, whereas those of lancetfish were observed in the 1990s.

摘要: Contamination by dexamethasone (DEX) in aquatic environments is expected to rise significantly as it is used in the treatment of inflammation, allergies, and autoimmune disorders, especially COVID-19. However, the underlying effects and mechanisms of DEX in leading to metabolic or infectious diseases have remained largely unexplored in teleosts. Here, we used zebrafish (Danio rerio) as a model to study the effects of DEX exposure on metabolic and infectious diseases. We found that DEX-induced hepatobiliary syndrome significantly increased susceptibility to type II grass carp reovirus (GCRV-II), which causes severe hemorrhagic disease in aquaculture. Comparative transcriptomic analysis demonstrated the shared and disease-specific immunometabolic responses among zebrafish larvae with hepatobiliary syndrome and/or GCRV-II infection. Moreover, compared with those of wild-type zebrafish, zebrafish larvae with DEX-induced hepatobiliary syndrome and/or GCRV-II infection presented increased expression of inflammatory markers (il1b), coagulation markers (fibrinogens and antithrombin III), and genes involved in autophagy, including hsp90aa. In vivo inhibition of autophagy via 3-MA and Hsp90 activity via geldanamycin markedly suppressed hepatic lipid deposition and reactive oxygen species accumulation caused by hepatobiliary syndrome and/or GCRV-II infection, thus significantly reducing the severity of disease and level of mortality induced by DEX and/or GCRV-II infection. In conclusion, our findings establish that the inhibition of autophagy and Hsp90 activity are promising therapeutic targets for DEX-induced hepatobiliary syndrome, GCRV-II infection, and DEX-induced hepatobiliary syndrome complicated with GCRV-II infection.

摘要: Water is an indispensable resource for sustaining life, ecosystems, and economic productivity. However, increasing contamination and pollution pose severe threats to global water purity, with significant risks to human health, biodiversity, and ecosystem stability. This study examines the diverse dimensions of water purity, including its impacts on ecosystems and human health, sources of pollution, global disparities, regulatory frameworks, and technological advancements. These factors are essential in addressing the escalating threats to water quality and public health. This study also explores the complex relationship between water contamination and food security, emphasising the role of water purification in disease prevention and sustainable food systems. It underscores the critical need for effective water purification strategies, exploring challenges and potential solutions, including applications of artificial intelligence and big data. The study highlights mechanisms to enhance transparency and accountability in water resource management through an analysis of policy frameworks and innovative practices. By evaluating the effectiveness of current purification methods and regulatory standards, the study provides valuable insights for sustainable water protection initiatives. Findings from this study highlight global water access and quality disparities, and suggests the need for targeted strategies to promote equity and a coordinated, international response to safeguard water resources. This study offers robust theoretical support for environmental protection policies and advocates for stronger local capabilities in addressing regional water challenges. It delivers a comprehensive framework to mitigate pollution risks, protect biodiversity, and promote public health, underscoring the global urgency of securing clean water access.

摘要: Estimating the individual feed intake (FI) for multiple consecutive meals of fish reared at commercial densities has long been a challenge and this difficulty has prevented the genetic improvement of feed efficiency (FE) in fish. We propose an automatic and real-time measurement system for individual FI of fish reared in a group based on computer vision and radio frequency identification fusion technology in large yellow croaker (Larimichthys crocea). To achieve this, we designed a feeding station where only one fish at a time can enter and have their passive integrated transponder (PIT) tag recorded. We then trained a feed pellet detection model based on You Only Look Once v5 using an annotated dataset, which achieved a final precision of nearly 100%. Finally, we utilized the trained feed detection model combined with PIT scanning to accurately and automatically track individual FI of fish with access to the feeding station. In 10 experiments lasting a total of 792 min conducted in the laboratory, the automatic real-time feed counting achieved an average accuracy of 94.5%. In addition, during a 14-day FI measurement period conducted in an indoor farm with 894 fish that received two meals per day, large yellow croaker feed efficiency ratio (FER) was 0.9 f 0.4 with a coefficient of variation of 47%. FER showed a weak positive correlation with initial body weight and a weak negative correlative with FI. There was also a moderate correlation between FER and body weight gain (BWG), with subgroups that had high BWG exhibiting greater FER values. The approach described here demonstrates a method to automatically and accurately investigate FER in fish that can be used to assess the potential for their genetic improvement.