摘要: On 29 January 2024, a truck accident spilled concentrated sulfonic acid into a river in Brazil's State of Santa Catarina. This disaster, which occurred in a protected area, killed various types of fish (e.g., crenuchids, heptapterids, and loricariids) and probably many other less observable animals, such as small invertebrates. The accident, similar to others around the world, gained national and international media attention. Because truck accidents causing aquatic pollution through chemical spills are occurring not just in Brazil but also globally, the recent event led us to consider similar cases and to recommend potential measures to help mitigate biodiversity loss in waterbodies near roads. Three factors need to be considered: (i) human (drivers); (ii) truck (mechanical condition); and (iii) road (e.g., infrastructure). In addition, improved expert assessments of the negative impact of these accidents on biodiversity are needed. A requirement to aid recovery of polluted ecosystems should be incumbent upon the companies involved in truck accidents.

摘要: The largemouth bass virus (LMBV) exhibits high pathogenicity in both adult and juvenile largemouth bass, causing substantial economic losses within the aquaculture industry. MicroRNAs (miRNAs) are crucial in controlling viral infections and the host's immune responses, making them significantly valuable in the treatment and diagnosis of diseases. Nevertheless, research on miRNA expression profiles associated with LMBV infection in largemouth bass is currently insufficient. This research attempts to investigate the roles and molecular mechanisms of miRNAs in the potential immune response and metabolic alterations triggered by LMBV infection in largemouth bass using miRNA sequencing. Following quality screening, the infection group and control group yielded a combined total of 142.73 million clean reads, with lengths predominantly at 22 nt. 1718 known miRNAs were identified, including 238 differentially expressed miRNAs (DEMs). In addition, 400 novel miRNAs were predicted, 36 of which were DEMs. To gain further insight into the immune and metabolic related biological functions of DEMs, target gene prediction was conducted. KEGG pathway analysis revealed that LMBV impacted pathways such as Endocytosis, Purine metabolism, Phosphatidylinositol, Fatty acid Biosynthesis, and Phagosome signaling systems, highlighting the vital role of miRNAs in immune responses and metabolic alterations. Furthermore, the miRNA-mRNA interaction network revealed crucial miRNAs and their corresponding target genes involved in conferring resistance against viral infections by utilizing metabolic and immune related pathways as the foundation. Ten DEMs were selected at random for real-time quantitative PCR (qRT-PCR), and results exhibited expression patterns that were consistent with sequencing data. These findings validate the immune and metabolic regulatory function of miRNAs against LMBV in largemouth bass, offering valuable perspectives for the prevention and management of illnesses linked to iridoviruses.

摘要: Stathmin 1 ( stmn1 ) gene, which is involved in the control of cell cycle progression, cell proliferation, differentiation and motility, is a crucial relay in the signal transduction of multiple signaling pathways. Reports on the function of stmn1 in fish are scarce. In this study, the characterization and function of stmn1a gene were explored in an important food fish, namely bighead carp ( Hypophthalmichthys nobilis ). The bighead carp stmn1a ( Hynstmn1a ) genomic sequence, which has 2995 bp with an ORF of 447 bp, is evolutionarily conserved in teleost fish. The highest level of expression of Hynstmn1a is in the un-fertilized eggs and spleen of adult bighead carp. The overexpression of Hynstmn1a facilitates cell cycle progression and suppresses apoptosis in EPC cells. In an siRNA assay, disruption of stmn1a in EPC cells resulted in the inhibition of cell cycle progression and promotion of apoptosis. Analysis of promoter activity indicated that an upstream transcription factor (foxo4) regulates Hynstmn1a . Zebrafish mutants with stmn1a knockout by CRISPR/Cas9 exhibited a significant retardation of body length ( p < 0.05). There was no significant difference in body weight between stmn1a -mutant zebrafish and wildtype ( p 1 / 4 0.053). A 22-bp Indel in the promoter region of Hynstmn1a with an observed heterozygosity (Ho) of 0.136 in a bighead carp population ( n 1 / 4 191). The polymorphism of this 22-bp Indel genotype is significantly associated with body length (BL), head length (HL) ( p < 0.05), body weight (BW), head height (HH), and head width (HW) ( p < 0.01), showing its genetic effects on growth promotion. This study sheds light on the function of stmn1a in fish and demonstrates the potential of the 22-bp Indel of Hynstmn1a as a gene marker when selecting breeding individuals for faster growth and a bigger head of bighead carp in aquaculture.

摘要: Moving bed biofilm reactors (MBBR) are equipment used to remove organic compounds and are frequently tested for aquaculture operations aimed at treating and reusing water. However, a limitation of MBBR is the long maturation period necessary for nitrification to occur efficiently. We evaluated biofilm maturation in MBBR with biomass adhered to support material using enriched medium-NH4Cl and a treatment without enrichment. Two independent recirculating aquaculture systems were established based on a freshwater fish farm that produced a daily total ammonia nitrogen concentration of 1.0 mg/L. Each treatment was composed of a reservoir and two experimental bioreactors that received support materials for the colonization of the adhered biomass. The results indicated that the enriched bioreactors performed slower, taking 29 days to reach maturity, while the control treatment matured at 27 days. The species Candidatus Nitrospira defluvii, responsible for acting in the nitrification process became more abundant in the control treatment where it represented 23% of the biofilm composition, while the enriched treatment presented only 3%. The results suggest that the nitrification process in the control treatment performed better than in the enriched bioreactors. However, the use of synthetic media such as NH4Cl and sodium acetate as sources of C:N associated with the Pimelodus maculatus effiuent during the start-up process had an important benefit to the maturation time of both bioreactors.

摘要: Micro(nano)plastics (MNPs) are a growing problem as persistent environmental pollutants. Here, we investigated the impact of MNPs on microorganisms in aquatic microbial floc exposed to NPs (80 nm) and MPs (8 mu m) for 35 days. Water quality indicators were tested weekly and microbiological analyses were conducted on Day 7 and 28 after exposure. The results showed that there were significant differences in the levels of total ammonia nitrogen or nitrite between the MNPs groups and the control group, spanning from Day 7 to Day 28. For the microbial response, microbial community richness in the NPs and MPs groups were significantly increased at Day 7. Functional prediction showed that the relative abundances of bacteria associated with the Forms Biofilms, Potentially Pathogenic, Plastic Degradation and nitrogen cycle processes were significantly different after MNPs exposure. The results suggest that MNPs had no significant effect on the microbial diversity of mature microbial flocs. Findings suggest MPs could cause an increase in the relative abundance of potentially pathogenic bacteria, while NPs do not. In addition, stress associated with MNPs affected the nitrogen cycle of microorganisms, and NPs exerted greater impacts than MPs. Findings from this study further our understanding of the impact of MNPs at environmentally relevant concentrations on microorganisms in aquatic ecosystems.

摘要: Parkinson's disease (PD) is the second most common neurodegenerative disease. Potassium voltage-gated channels are potential targets for the treatment of PD. The aim of this study is to identify novel potassium ion channel blockers for the treatment of PD through transcriptomic analysis of the coral species Galaxea fascicularis. After annotation by four different databases, four peptides were selected that showed characteristics of potassium ion channel blockers. These four peptides were subjected to multiple sequence alignment and phylogenetic analysis. These four peptides were identified as of Kunitz-type peptides, are known as potassium ion channel blockers. The structures of the peptides were modeled and subjected to molecular dynamics (MD) simulation to verify their stability, which indicated that the peptide GfKuz1 showed the highest potency to block KV1.3 (potassium voltage-gated channel subfamily A member 3) among the reference peptides. The MD simulation of the peptide-protein complexes showed that GfKuz1 interacted with KV1.3, and was more compact and stable than the other potassium ion channel. The blocking effect was confirmed by a potassium ion bioassay. Furthermore, GfKuz1 showed no toxicity to PC-12 cells or zebrafish at concentrations up to 100 mu M. In addition, GfKuz1 increased the PC-12 cell viability that was reduced by 6-hydroxydopamine hydrochloride, and also down-regulated the level of reactive oxygen species and activated the Nrf2 pathway. In summary, GfKuz1 reversed PD symptoms and is a potential peptide drug prototype for PD treatment.

摘要: Aquaculture is one of the fastest-growing agricultural sectors globally and is becoming increasingly important for producing sustainable and healthy diets with relatively low climate impacts. In comparison to livestock production, especially beef, seafood production has lower carbon emissions. Additionally, some species can extract carbon from aquatic environments, contributing to an extended carbon cycle. However, the potential for negative environmental consequences in aquaculture production might increase with the growing global population and demand for aquatic food. Herein, we review the environmental consequences of aquaculture production and the potential effects of different aquatic products on greenhouse gas (GHG) emissions. We also summarize approaches to improving environmental footprints for mitigating global climate change. Key elements, including improving feed efficiency, selecting suitable farmed species, and implementing sustainable farming practices and management in aquaculture, are discussed, as well as the trade-offs between aquaculture and capture fisheries. Crucially, performance gaps among farmed species underscore the potential for consumer-oriented advice to significantly reduce the effects of aquaculture on climate change. However, uncertainties and knowledge gaps related to carbon sequestration and GHG emissions in aquaculture ponds necessitate further research. Overall, holistic evaluation and strategic intervention regarding GHG emissions are fundamental and essential for achieving a sustainable, low-carbon future for aquaculture.

摘要: Harmful algal blooms are important threats to reservoir condition. Over a 15-year period, we sampled five Argentinian reservoirs to identify the responsible species for harmful algal blooms and determine the water quality factors driving their occurrence. These reservoirs exhibit diverse morphological and hydrological characteristics and are distributed across varying climatic zones. Cyanobacterial blooms included an array of species, including toxin producers such as Raphidiopsis raciborskii, Aphanizomenon gracile, and Microcystis aeruginosa. In contrast, dinoflagellate blooms were predominantly characterized by Ceratium. The cyanobacterial blooms primarily occurred in the shallower reservoirs located in warmer regions, whereas dinoflagellate blooms occurred where temperatures were lower. The most intense blooms occurred during the summer, and although cyano-bacterial and chlorophyte blooms co-occurred, they never coexisted with dinoflagellate blooms. We identified cyanotoxins in the reservoirs over the past three years, a phenomenon previously unreported in the region. Given that these reservoirs are drinking water sources for human populations, ongoing and systematic monitoring is needed to protect public health. Controlling the proliferation of algae and cyanobacteria in reservoirs requires resource management at the watershed level, and in the case of the Itiyuro and El Limon, requires binational management with Bolivia.

摘要: The East Zhejiang Canal is an artificial waterway located in the plains of East China. Because of its role in providing social services, it is frequently subjected to human activities affecting its health. To improve the water resource management and condition of this canal, assessment of its ecological health is necessary. We measured water quality variables and benthic diatom and macroinvertebrate assemblages to evaluate the ecological status of the canal. We found that the canal was eutrophic with an average chemical trophic level index of 64.3 and an average trophic diatom index of 68.1 (with Nitzschia palea, Melosira varians, and Navicula rostellata, Encyonema minutum abundant). Macroinvertebrate assemblages also showed that the canal was eutrophic based on the dominance of Limnodrilus sp. A low BMWP (Biological Monitoring Working Party) score further indicated the poor water quality of the canal. Correlation analysis indicated that phosphorus was the main driver of eutrophication in the canal. Consequently, more attention should be paid to reduce phosphorus loadings.

摘要: Water stratification is a prominent oceanographic phenomenon in the North Yellow Sea, a vital region for mollusk aquaculture in northern China. Understanding the influences of water stratification on planktonic bacterial communities in those waters is crucial for the sustainable development of mollusk aquaculture in this region. In the present study, the bacterial community profiles across different water layers in a representative Yesso scallop farming area of Zhangzi Island in the North Yellow Sea were surveyed from March 2021 to January 2022. Water stratification was present in June, July, and August (the stratification period, abbreviated as S period) and absent in March, October, and January (the mixing period, abbreviated as M period), based on the vertical distribution of water temperatures. Results of the 16S rRNA gene sequencing showed that the alpha diversity of bacterial communities in the S period (Chao1 index: 500.78, Shannon index: 6.85) was significantly lower than in the M period (Chao1 index: 575.00, Shannon index: 7.24). The relative abundances of Synechococcus CC9902 and Vibrio were significantly higher in the S period compared to the M period, while the abundance of Clade Ia showed the opposite trend. Water temperature, salinity, and dissolved inorganic nitrogen were identified as the main environmental drivers of the bacterial communities, which accounted for 22.4%, 20.0%, and 17.1%, respectively, of the total variation in bacterial community composition. Functional prediction suggested that the pathways associated with cytochrome biosynthesis and nutrient utilization of the bacterial communities were significantly enriched in the S period, while those involved in energy metabolism were enhanced in the middle and bottom layers compared to the surface layer during the S period. The connectivity of the molecular ecological network increased in the S period, with the number of edges, average degree, and average clustering coefficient being 574, 11.36, and 0.57 in the S period and 524, 9.44, and 0.51 in the M period, respectively. Collectively, these results indicated that water stratification led to a decrease in bacterial community diversity and an increase in the relative abundance of Synechococcus CC9902 and Vibrio, which were potentially detrimental to mollusk health and aquaculture. Our results contribute to clarifying the dynamics of planktonic bacterial communities and their impacts on mollusk aquaculture in the context of intensifying ocean stratification.