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.

摘要: Because of anthropogenic and natural factors, zooplanktivorous fish often dominate fish assemblages within lake ecosystems along the middle and lower reaches of the Yangtze River Basin (MLYRB), China. Despite their prevalence, the density-dependent effects of zooplanktivorous fish on lake food webs within the MLYRB are poorly understood compared to other omnivorous fish. We conducted a mesocosm experiment to quantify how plankton communities and water quality responded to varying densities of a common zooplanktivorous fish (Thin Sharpbelly Toxabramis swinhonis). During the experiment, the mean weekly total nitrogen (TN), total phosphorus (TP), ammonium nitrogen (NH4 & thorn;-N), chemical oxygen demand (CODMn), turbidity, and chlorophyll-a (Chl.alpha) values in treatments where Thin Sharpbelly were present (i.e., fish-present) were all significantly higher than those in the control treatment with no Thin Sharpbelly (i.e., fish-absent). In addition, all water quality variables exhibited a significant positive relationship with the density of Thin Sharpbelly. The abundance and biomass of phytoplankton in the fish-present treatments were significantly higher than in the fish-absent treatment, with Pseudanabaena spp., Dolichospermum spp., and Limnothrix spp. dominating the phytoplankton assemblage. The biomass and abundance of small-bodied zooplankton increased with fish density, whereas the relative abundance and biomass of large-bodied zooplankton (cladocerans and copepods) showed the opposite trend. Also, the ratio of zooplankton to phytoplankton biomass declined nonlinearly with fish density, while the ratio of Chl.alpha to TP was significantly positively correlated with fish density. Collectively, experimental results indicated that zooplanktivorous fish increased the concentrations of nutrients and stimulated phytoplankton growth through feeding on large zooplankton and the strength of these effects increase with fish density. Moreover, results indicate that high densities of zooplanktivorous fish can alter plankton assemblage structure by facilitating growth of undesirable cyanobacteria and shifting the composition of zooplankton to smaller-bodied species and forms. Our results demonstrate how Thin Sharpbelly, and potentially other obligate zooplanktivorous fish, can have adverse effects on water quality and plankton assemblages, but these responses are density dependent. Our findings suggest that managing the density of zooplanktivorous fish could be a useful ecological rehabilitation measure for improving water quality in MLYRB lakes.

摘要: The black rockfish (Sebastes schlegelii) is a marine species that is economically important in aquaculture, and the efficiency of its spermatogenesis is vital for its success in the aquaculture industry. Spermatogonia serve as the foundation of spermatogenesis in fish, possessing the ability for continuous self-renewal and progressive differentiation into mature spermatozoa. Moreover, Sertoli cells are crucial in modulating the proliferation and differentiation of spermatogonia. This study focused on the regulation of glycolysis by PLIN2a in Sertoli cells of the black rockfish and examined how the inhibition of glycolysis in these cells impacted the proliferation and differentiation processes of spermatogonia. We found that effective regulation of glycolysis was crucial for the metabolic activity and functional maintenance of Sertoli cells in black rockfish. Overexpression of plin2a in vitro enhanced glycolysis in Sertoli cells, whereas inhibition of glycolysis impaired their normal metabolic activity. In vivo inhibition of glycolysis in black rockfish testes lead to apoptosis of Sertoli cells and significantly suppressed the proliferation and differentiation of spermatogonia. These results underscore the essential role of glycolysis in the development and metabolic activity of Sertoli cells and highlight the critical regulatory role of glycolysis in determining the fate of spermatogonia. This study emphasizes the importance of regulating energy metabolism pathways, particularly glycolysis, in Sertoli cells to indirectly influence the development of spermatogonia, offering significant insights into the reproductive mechanisms of black rockfish and other teleost species.

摘要: To explore the modulatory role of miR-144 in Nrf2 cascade reactions and assess its potential as a target for alleviating oxidative fish oil-induced intestinal damage in Megalobrama amblycephala, four experimental diets were formulated. A conventional diet was kept as the control diet (NC), while experimental diets consisted of the control diet supplemented with oxidized fish oil (OF, peroxide value: 323 mmol/kg), OF & thorn; miR-144 agomir and OF & thorn; miR-144 antagomir, respectively. In the oxidative stress model of M. amblycephala induced by oxidized fish oil, dihydroethidium (DHE) fluorescence probe and morphological results revealed that oxidized fish oil markedly elevated the level of reactive oxygen species (ROS) within intestinal cells and destroyed the intestinal barrier structure, such that the height of the intestinal villus and the thickness of the muscle layer were significantly reduced, and intestinal barrier-related genes ZO-1, Occludin and Claudin-7 alpha were significantly down-regulated. Additionally, oxidized fish oil treatment activated autophagy and apoptosis of intestinal cells, which was manifested by the significant up-regulation of autophagy-related genes Beclin-1, VPS34, P62 and ATG5 (P < 0.05), the increase of autophagosomes, and the significant up-regulation of apoptosis-related genes HSP27, Caspase3, Cas-pase8 and Caspase9 (P < 0.05). Further studies showed that miR-144 agomir significantly enhanced Keap1 expression and inhibited Nrf2 expression, while miR-144 antagomir had the opposite effect. Importantly, forced expression of miR-144 induced ROS accumulation by silencing Nrf2, raised the expression of inflammatory factors (P < 0.05), and even further induced the development of autophagy and apoptosis, while miR-144 antagomir could offset this effect by reactivating Nrf2 expression. In summary, this study showed that silencing miR-144 could protect intestinal cells of M. amblycephala from oxidative damage by targeting the Nrf2 signaling pathway. Therefore, miR-144 is expected to be a regulatory target for ameliorating intestinal oxidative damage induced by oxidized oils.

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: Freshwater brown algae have been acknowledged as the least diverse of all groups of freshwater algae. Morphological and molecular investigation were conducted on a freshwater brown alga collected in this study. Morphological characterization and phylogenetic tree based on the rbcL gene confirmed its attribution to Heribaudiella fluviatilis. The complete organelle genomes of H. fluviatilis were determined and assembled from highthroughput sequencing. A circular tetrad structure of 128,880 bp was identified for the chloroplast, and the mitochondrial genome was assembled as a circle with 43,657 bp in length. This study provides the first and only record of organelle genomic information of the freshwater Phaeophyceae, which are important for understanding the endosymbiosis theories. Concatenated (Bayesian inference, maximum likelihood under MFP and GHOST models) and coalescent methods were used to construct the phylogenetic relationship among secondary plastidbearing lineages based on organelle genomes. Obvious conflicts were observed in grouping relationships of chloroplast and mitochondrial genomes, even among different evolutionary models and tree-constructing methods. The transcriptome of H. fluviatilis was sequenced and used to construct the phylogenetic relationship among secondary plastid-bearing lineages. The phylogenetic relationships in nuclear and mitochondrial genomes were consistent in grouping CHSR taxa (cryptophytes, haptophytes, stramenopiles and rhizarians) in an independent branch. The phylogenetic relationship constructed from nuclear transcriptomes was highly reliable by owning robust supporting values on each node and was consistent with the serial endosymbiosis theory on evolution of red secondary plastid-derived lineages.

摘要: Proteins in aquatic products satisfy the increasing demand of high-quality proteins of humans, resulting in a rapid development of freshwater aquaculture. However, bacterial diseases in aquatic animals often cause economic losses worldwide. Antibiotics are frequently used in aquaculture to deal with bacterial infections, but antibiotic resistance has restricted its application. Therefore, it is necessary to develop drugs on account of novel strategies. Here, aerolysin, the main virulence factor of Aeromonas hydrophila (A. hydrophila), was defined as a target to develop anti-virulence drugs. The results showed that Licochalcone A (LCA) with little bacteriostatic activity could decrease the hemolytic activity of aerolysin without affecting its production. The binding mode and potential binding sites were determined following molecular docking and dynamic simulation. Ser33 and Pro365 were confirmed to be the main binding sites according to the results of fluorescence quenching assay with mutated aerolysin. The mechanism by which LCA inhibited aerolysin was hindering its pore-forming activity. Moreover, cell viability assays and animal studies demonstrated that LCA could provide a significant protection to human alveolar epithelial cells from aerolysin-mediated cell damage and decrease the pathogenicity of A. hydrophila to channel catfish. These findings suggested that LCA might be a novel candidate for treating A. hydrophila infections and partly determined the mechanism of herbal medicine in dealing with bacterial infections.

摘要: The presence of microplastics in the marine environment poses a potential threat to juvenile and adult sea cucumbers; however, the effects of microplastics on the early developmental stages of sea cucumbers are poorly understood. In this study, the larvae of Holothuria leucospilota were exposed to polystyrene (PS) particles of varying sizes (1-60 mu m) to investigate the influences of microplastics on food ingestion, digestion, and performance of larval H. leucospilota at different developmental stages. The fluorescence tracing experiment revealed that the early- and mid-auricularia were capable of ingesting particles up to 20 mu m in size, whereas lateauricularia larvae could ingest particles up to 40 mu m in size. It was observed that microplastic particles accumulated in the stomach of larvae over a certain period, making it difficult for them to eliminate. Microplastic particles of 10 mu m could be observed aggregating in the stomach of larvae at all developmental stages. The 20 mu m and 40 mu m particles had limited effects on larval survival but caused developmental retardation. Larvae that were exposed to 10 mu m and 60 mu m particles had significantly lower survival rates compared to the control group. Moreover, microplastics had a negative effect on the growth of larvae, and larger particles (20 mu m, 40 mu m and 60 mu m) had greater effects than smaller ones (1 mu m, 5 mu m and 10 mu m). The presence of microplastics hindered the development and metamorphosis of larvae, in particular by inhibiting the maturation of their ciliary band and esophagus. In conclusion, microplastics have negative impacts on larval H. leucospilota, and therefore, effective measures should be taken to prevent the introduction of microplastics into hatcheries artificially breeding sea cucumbers.