This study characterized Aeromonas veronii isolates recovered from diseased Micropterus salmoides , Procambarus clarkii , and Ctenopharyngodon idella in Guangxi, China. The objective was to assess genetic diversity, virulence gene profiles, and antimicrobial resistance patterns to support effective disease control. Seven strains were confirmed as A. veronii using morphological, physiological, biochemical, and molecular methods. Virulence gene screening showed that all isolates carried GcaT, OmpAI, Hly, Fla, and Exu. Artificial challenge tests demonstrated strong pathogenicity, with median lethal dose (LD₅₀) values ranging from 1.43×10⁶ to 3.58×10⁶ CFU/individual. Antimicrobial susceptibility testing indicated sensitivity to ceftriaxone, cefepime, and fosfomycin, but resistance to amoxicillin, teicoplanin, and sulbactam. Multilocus sequence typing (MLST) identified seven novel sequence types (ST2742, ST2740, ST2765, ST2760, ST2770, ST2774, and ST2775). These results confirm that A. veronii isolates from Guangxi exhibit high genetic diversity, carry multiple virulence genes, and display multidrug resistance. The findings provide a basis for epidemiological surveillance and targeted control of this pathogen.
China’s marine aquaculture sector is essential to aquatic food supply and coastal employment, yet its environmental performance varies markedly among fed finfish and crustacean systems, filter-feeding bivalves, macroalgal farms, and integrated multi-trophic aquaculture (IMTA). This critical structured narrative review synthesizes evidence on nutrient discharge, organic deposition, benthic alteration, hydrodynamic modification, disease and chemical risks, nutrient bioextraction, ecological carrying capacity, and adaptive monitoring in coastal marine systems. Unlike a systematic review, the approach uses an explicit search framework and structured synthesis questions to compare mechanisms and boundary conditions, but it does not claim exhaustive retrieval, formal risk-of-bias scoring, or pooled effect estimation. Evidence indicates that fed systems are principal sources of nitrogen, phosphorus, and particulate organic waste, whereas shellfish and seaweed can remove nutrients through harvest but may also generate context-dependent effects through biodeposition, food depletion, shading, flow modification, and density-dependent competition. Bay-scale observations reinforce this scale dependence: winter monitoring in Sansha Bay reported mean nitrate and phosphate concentrations of 31.3 ± 10.5 and 2.26 ± 0.84 μM, respectively, with most observations meeting a eutrophic classification, while long-term shellfish-seaweed culture in Sanggou Bay has shown comparatively limited benthic deterioration under some conditions but stronger seasonal stress during warmer months. IMTA can improve nutrient recovery and diversify production, although performance depends on trophic matching, spatial configuration, hydrodynamics, harvest timing, biosecurity, and market viability. The review concludes that sustainable transition requires bay-scale nutrient budgets, water and sediment indicators linked to predefined management triggers, feed and stocking controls, harvest-based accounting for extractive species, site-specific carrying-capacity assessment, and performance-based licensing. China’s future mariculture policy should therefore distinguish farming systems based on their environmental functions and regulate cumulative effects at the spatial scale at which they occur.
The purpose of this study was to investigate the effects of betaine supplementation in high-carbohydrate diets on the antioxidant capacity and glycolipid metabolism of juvenile largemouth bass ( Micropterus salmoides ). Six experimental diets were designed, including a low-carbohydrate diet (8% starch, LC), a high-carbohydrate diet (20% starch, HC), and four gradient betaine supplementation groups (designated as HCB1, HCB2, HCB3, and HCB4 in turn) with 0.5%, 1.0%, 1.5%, and 2.0% betaine supplemented to the high-carbohydrate diet, respectively. A total of 270 juvenile largemouth bass with an initial body weight of 4.34±0.11 g were used for an 8-week feeding experiment. The results showed that, compared with the LC group, the HC group exhibited significant oxidative stress in the liver and disorders of glucose and lipid metabolism in juvenile largemouth bass. However, betaine maintained the glycolipid metabolic homeostasis of the organism by significantly down-regulating the transcriptional expression of key lipid synthesis genes (ACC1 and FAS), inhibiting excessive hepatic lipid synthesis, reducing the serum levels of glucose (GLU), triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C), and decreasing abnormal lipid accumulation. In addition, the improvement in hepatic antioxidant capacity induced by betaine was mainly associated with the Nrf2-Keap1 pathway, which significantly upregulated the transcription of key antioxidant genes (SOD and GPX), elevated superoxide dismutase (SOD) activity, and increased reduced glutathione (GSH) content. In conclusion, dietary supplementation with 0.5% betaine not only enhances the growth performance but also improves hepatic antioxidant capacity and maintains hepatic metabolic homeostasis of juvenile largemouth bass under high-carbohydrate feeding conditions, providing more comprehensive theoretical support for the research on betaine in carbohydrate diets for carnivorous fish.
In this study, we conducted a comprehensive genome survey of Selenotoca multifasciata using Illumina short-read sequencing technology. A total of 51.63 Gb of high-quality clean sequencing data were generated, with Q20 and Q30 values reaching 98.77% and 96.64%, respectively. The 42.59 Gb of clean reads were assembled into 551,813 contigs (587.82 Mb) and 431,116 scaffolds (593.38 Mb). 17-mer frequency analysis estimated a genome size of 575.38 Mb, with 42.20% GC content, 0.43% heterozygosity, and 25.97% repeat ratio. 214,419 SSR loci were detected genome-wide, with dinucleotide repeats being the most prevalent type (80.49%) and AC/AG as the dominant motifs. Among 53 tested markers, 30 produced clear and stable bands, and 9 polymorphic loci were applied to assess the genetic diversity of a wild S. multifasciata population from Zhanjiang Bay. These results provide a valuable genomic basis for whole-genome sequencing and molecular marker development in S. multifasciata and related Scatophagidae species.
Since the 18th National Congress of the Communist Party of China, the implementation of the maritime power strategy has been accelerated. However, China still has inadequate imbalances in its comprehensive understanding and management of the oceans. The current trend of “anti-globalization” is gradually rising. Western developed countries are developing and developing marine resources. Maritime channel control, polar oceans, and other aspects are constantly accelerating the cross-integration of information technology comprehensive acquisition of marine information, and the development of the marine information industry is imminent. The Fifth Plenary Session of the Nineteenth Central Committee of the Party made important arrangements for accelerating the development of digitalization, which provided a fundamental basis for the development of the marine information industry. Vigorously developing the marine information industry and deepening the cross-integration of the ocean and information is of great strategic significance for the development of marine undertakings and the building of a maritime power. This paper analyzes the current status and problems of my country’s marine information industry in terms of infrastructure, technology and equipment, market development, policy guarantees, etc., by studying the definition and industrial chain of the marine information industry, combined with the spirit of the Fifth Plenary Session of the 19th Central Committee of the Communist Party of China, and proposes Suggestions for accelerate the development of the marine information industry.
This study aimed to determine the optimal dietary copper requirement for juvenile bighead carp (Aristichthys nobilis). Six diets were formulated by supplementing a basal diet with 2.49, 5.15, 7.99, 14.11, 25.75 and 49.21 mg/kg copper from CuSO4 center dot 5H(2)O. 900 Juvenile bighead carp (initial weight: 1.40 +/- 0.04 g) were fed these diets for 67 days to biochemical indices, and digestive enzyme. Weight gain rate (WGR) and specific growth rate (SGR) peaked at 1356.98% and 3.98% day-1 in the 14.11 mg/kg copper group, significantly exceeding the control group (P<0.05). Copper accumulation exhibited tissue specificity: liver > intestinal wall > vertebrae > gill > muscle. Dietary copper improved hepatic function, evidenced by reduced serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT), alongside enhanced calcium and phosphorus metabolism. The addition of dietary copper inhibited the activities of intestinal amylase and lipase. The results demonstrated that dietary copper levels of 7.99-25.75 mg/kg significantly improved liver function, enhanced serum calcium and phosphorus, and promoted erythropoiesis, hematocrit, and hemoglobin synthesis. Broken-line regression analysis identified the optimal copper requirement as 12.13-12.23 mg/kg for maximal WGR and SGR. These findings provide a practical basis for copper supplementation in bighead carp aquaculture.
Accurate species delimitation is essential for phylogeny, phylogeography, ecology, conservation, and biogeography. In China, the cyprinid genus Acrossocheilus is of economic and ecological importance, but species boundaries remain controversial because several nominal species exhibit overlapping diagnostic characters and uncertain phylogenetic affinities. Here, we analyzed 31 publicly available complete mitochondrial genomes representing 22 cyprinid taxa, including 16 nominal Acrossocheilus taxa, three Onychostoma taxa, and three Spinibarbus outgroups. We extracted and concatenated the 13 mitochondrial protein-coding genes (ATP6, ATP8, COX1, COX2, COX3, CYTB, ND1, ND2, ND3, ND4, ND4L, ND5, and ND6) and reconstructed phylogenetic relationships using Bayesian inference and maximum-likelihood methods. Species boundaries were evaluated using four complementary approaches: Generalized Mixed Yule Coalescent (GMYC), Bayesian Poisson Tree Processes (bPTP), Automatic Barcode Gap Discovery (ABGD), and Bayesian Phylogenetics and Phylogeography (BPP). The combined analyses supported 15 molecular operational taxonomic units (MOTUs), with bPTP and ABGD showing high congruence when ABGD prior intraspecific divergence was set between 0.001 and 0.0144. The results highlighted several taxonomically important patterns, including possible conspecificity among A. longipinnis , A. iridescens , and A. barbodon ; divergent placements of two A. paradoxus accessions; and unresolved generic boundaries between Acrossocheilus and Onychostoma . Because the present inference is based only on mitochondrial loci and uneven taxon sampling, these MOTUs should be interpreted as testable molecular hypotheses for future integrative taxonomy using nuclear markers, broader sampling, and morphology-based validation.
The marine information industry is a core component of the digital marine economy, characterized by its wide coverage and strong economic driving force. To accurately reflect its development status, this study first clarifies the definition of the marine information industry (taking marine information as the core resource, covering equipment manufacturing, software development, and information services related to marine information production, collection, transmission, processing, and application) and constructs a “perception-transmission-processing-application” industrial chain system. Based on the National Economic Industry Classification (GB/T 4754-2017), the industry is divided into a core layer (4 categories: marine information collection, communication and transmission, storage and analysis, application and sharing services) and a support layer (1 category: marine information supporting industry), totaling 11 sub-industries. Subsequently, a marine information enterprise identification method based on big data mining is established, integrating enterprise names, core businesses, patent information, and other multi-source data, and using text feature matching and machine learning algorithms for accurate identification. Finally, three value-added calculation methods (industry stripping method, value-added rate method, and input-output method) are proposed for different types of sub-industries. The trial calculation of T city’s 2022 marine information industry reveals that marine information communication and transmission account for 49% of the total value-added, storage and analysis for 24%, application and sharing services for 13%, and supporting industries for 12%. This method is suitable for value-added calculation when basic data is detailed, providing a standardized calculation framework for marine information industry statistics and filling the gap in current research on marine-derived industry accounting. It also offers a reference for the accounting of other marine-derived industries. Beyond its contribution to marine industrial statistics, this framework is directly relevant to aquaculture and fisheries management by enabling standardized accounting of marine information infrastructures that support stock assessment, environmental monitoring, biosecurity surveillance, and evidence-based decision-making for sustainable aquatic food systems.
Optimizing nutritional strategies for coral propagation in land-based Recirculating Aquaculture Systems (RAS) is critical for reef restoration. However, the interaction between colony morphology and particulate heterotrophy remains poorly understood, leading to inconsistent survival and growth outcomes in nurseries. This study evaluated the influence of particulate organic feeding (Reef-Roids) and trace element supplementation on two morphologically distinct species Acropora hyacinthus (tabular) and Acropora muricata (branching) across three size classes (1, 2, and 3 cm) over 88 days. The results identified a "morphological filter" effect: while heterotrophy is often beneficial, it induced a significant nutritional paradox in the tabular morphology. A. hyacinthus exhibited extreme sensitivity to organic loading, with the "Food" treatment resulting in a tenfold increase in mortality risk (Hazard Ratio = 10.22, p < 0.001) compared to the control. In contrast, the branching architecture of A. muricata facilitated superior resilience to organic entrapment, maintaining stable survival and leveraging heterotrophy for enhanced growth. Across both species, the 1 cm size class consistently achieved the highest specific growth rate (SGR), peaking at 0.89 +/- 0.37%.day-1 for A. hyacinthus under oligotrophic conditions. Trace element supplementation was found to significantly mitigate mortality in tabular corals under high-stress organic loading but could not fully compensate for growth inhibition caused by bio-fouling. These findings emphasize that coral mariculture success is morphology-dependent, requiring stratified management: oligotrophic tracks for tabular species and nutrient-enhanced regimes for branching forms to maximize RAS production efficiency.
Microalgae are rich in nutrients and health-promoting compounds, with great potential as aquatic feed ingredients. This trial was conducted to evaluate the effects of replacing dietary fish oil with docosahexaenoic acid (DHA) rich microalgae Schizochytrium meal for rainbow trout ( Oncorhynchus mykiss ) larvae. Five diets were prepared by using Schizochytrium meal to replace 0% (R0), 25% (R25), 50% (R50), 75% (R75), or 100% (R100) fish oil DHA in the control diet (crude protein, 52%; crude lipid, 15%). Rainbow trout larvae (initial body weight 0.25 ± 0.01 g) were fed the diets in square fiberglass tanks for 56 d. Survival, final body weight, weight gain, specific growth rate, and final body length were not significantly affected by the substitution of fish oil with Schizochytrium meal (P>0.05). Trypsin, amylase, lipase, leucine-aminopeptidase (LAP) and alkaline-phosphatase (AKP) activities were not affected by dietary treatments (P>0.05). No significant differences were observed in body C16:0, mono-unsaturated fatty acids (MUFA), SFA (saturated fatty acids), DHA and n-3 fatty acids content in fish among dietary treatments (P>0.05). C14:0, C16:1n-7, eicosapentaenoic acid (EPA), C20:4n-6 content, and n-3/n-6 ratio significantly decreased, while C18:0, C20:0, C18:1n-9 content, DHA/EPA ratio significantly increased in fish as Schizochytrium meal replacement level increased from 0% to 100% (P<0.05). C18:3n-3, C18:2n-6, polyunsaturated fatty acids (PUFA) and n-6 fatty acids content in fish increased with increasing Schizochytrium meal replacement level (P<0.05). There were no statistically significant differences in intestinal fold height, enterocyte height and microvillus height among all test treatments (P>0.05). The results of this study denoted the good nutritional value of DHA rich Schizochytrium meal as a replacement of fish oil in microdiets without negatively affecting survival, growth, and activities of digestive enzyme rainbow trout larvae.
Port-industry-city integration is a new era issue facing coastal cities. Promoting the integrated development of port and city is conducive to enhancing the vitality of the city, promoting industrial development and optimizing the functional of the port. As an important strategic resource of the China, Tianjin Port is the gateway to the sea for the Beijing-Tianjin-Hebei region, the sea-land intersection of the “the Belt and Road”, and an important node of the New Eurasian Land Bridge. The integrated development of port-city-industry can maximize the advantages of port resources and better serve the coordinated development of urban areas. Based on this, this article analyzes the models of integrated development of port-city-industry at home and abroad, the subjective and objective contradictions in the process of integrated development and proposes suggestions for the integrated development of port- city-industry in Tianjin.
This study evaluated the dose-dependent effects of dietary garlic (Allium sativum) supplementation on growth performance, survival, and hematological parameters of juvenile bighead catfish (Clarias macrocephalus) reared under low-salinity (2%o) conditions. A 60-day feeding trial was conducted using four experimental diets containing 0, 10, 20, and 30 g kg(-1) garlic powder in a completely randomized design with triplicate groups. Fish fed 20 g kg(-1) garlic exhibited growth performance (final mean weight, weight gain, daily weight gain, and specific growth rate in weight) comparable to the control and significantly higher than that of fish fed 10 g kg(-1) (P <. 0.05). In contrast, the 30 g kg(-1) treatment showed intermediate values. Survival was highest at 20 g kg(-1) and significantly reduced at 30 g kg(-1) (P <. 0.05). Feed conversion ratio, and most monitored hematological parameters were not significantly affected by dietary treatments (P >= 0.05), although leukocyte count was significantly higher at 20 g kg(-1) compared to 30 g kg(-1) (P <. 0.05). These findings indicate a dose-dependent response to garlic supplementation, with 20 g kg(-1) representing an appropriate inclusion level under the present conditions. The results provide practical implications for the use of garlic as a functional feed additive in aquaculture systems affected by salinity intrusion. Further studies incorporating functional and mechanistic analyses are recommended to clarify the underlying biological processes.
The Japanese eel (Anguilla japonica) is an important aquaculture species in East Asia, but pronounced growth heterogeneity within cultured populations remains a major constraint to production efficiency. To investigate the molecular basis of growth retardation, this study compared the dorsal muscle transcriptomes of fast-growing eels (FGEs) and slow-growing eels (SGEs) after an 8-week feeding trial. RNA-seq was performed on individuals with extreme growth phenotypes. A total of 638 differentially expressed genes (DEGs) were identified, including 186 upregulated and 452 downregulated genes in FGE relative to SGE. Functional enrichment analysis showed that FGE preferentially upregulated genes involved in lipid transport, amino acid and carbohydrate metabolism, and muscle structural assembly, indicating a favorable anabolic state. In contrast, SGE exhibited significant enrichment of pathways related to p53 signaling, circadian rhythm, PPAR signaling, and cardiomyopathy-associated structural remodeling. Several stress-and growth-inhibitory genes, including igfbp3, mstn, socs3, gadd45 alpha, and sesn1, were highly expressed in SGE. In contrast, genes associated with nutrient utilization and myofiber development, such as fabp7, apoe, and actc1, were more highly expressed in FGE. qRT-PCR validation confirmed the reliability of the transcriptomic results. These findings suggest that growth retardation in A. japonica is associated with stress-induced anabolic inhibition, metabolic reprogramming, circadian disturbance, and impaired muscle structural development, rather than simply reduced nutrient supply. This study provides new insight into the molecular mechanisms underlying growth heterogeneity in A. japonica aquaculture.
This study evaluated the effects of two aquaculture modes on Procambarus clarkii growth, size distribution, and muscle quality. Two models were compared: Pond A (high density: 4,428 ind/mu, small size: 3.5 g; control group) and Pond B (low density: 2,261 ind/mu, large size: 9.0 g) over 30 days. Results showed that Pond B significantly enhanced weight gain and the proportion of size 1 and size 2 compared to Pond A (P<0.05), while the control group exhibited a higher hepatosomatic index and proportion of Size 4 crayfish. Although proximate composition (moisture, lipid, ash) and muscle textural properties (hardness, springiness, chewiness, etc.) were unaffected, Pond B crayfish showed significantly lower muscle crude protein content and reduced levels of specific amino acids (glutamate, serine, tyrosine, methionine, lysine; P<0.05). Fatty acid analysis revealed significantly higher saturated (C16:0, C18:0) and monounsaturated (C16:1, C20:1) fatty acids, but lower C18:1n9, linoleic acid (LA), and docosahexaenoic acid (DHA) in Pond B (P<0.05); linolenic acid, arachidonic acid, eicosapentaenoic acid (EPA), and total PUFA remained unchanged. The low-density/large-size model optimizes growth performance and commercial size yield, increasing high-value individuals. However, it compromises specific nutritional aspects (protein, certain amino acids, and key fatty acids). As essential amino acid totals, proximate components (excluding protein), PUFA, and texture were unaffected, this model is recommended for maximizing economic return, though dietary strategies to mitigate nutritional alterations warrant further investigation.
Acanthopagrus schlegelii is an economically important coastal species whose enhancement and aquaculture performance are closely linked to habitat conditions. However, habitat degradation has constrained its sustainable utilization. In this study, controlled laboratory observations were conducted using four individuals per trial, with each experimental group observed continuously for 24 h and three replicate groups established. Four habitat treatments were tested: artificial reef, artificial seaweed reef, artificial seaweed, and barren water control. Spatial distribution, residence time, and swimming path length were quantified. Habitat type significantly affected habitat selection and behavioral responses. Fish showed a clear preference for structurally complex habitats, with occurrence frequency in the artificial reef and artificial seaweed reef treatments markedly higher than in the artificial seaweed and barren water treatments. Temporal aggregation patterns also differed among habitats: fish tended to aggregate around the artificial reef in the early morning, whereas use of the artificial seaweed reef peaked around midday. Residence time was longer in structured habitats, especially at night, and swimming path length was greatest in artificial reef treatments, followed by artificial seaweed reef, while the barren control showed the lowest activity range. These results indicate that habitat structural complexity and spatial heterogeneity strongly regulate habitat selection and behavioral adaptation in A. schlegelii . They also provide practical support for the use of composite-structured habitats in aquaculture enrichment and artificial habitat design.
This work aimed to comprehensively study the muscle nutritional components of Schizothorax wangchiachii with different specifications. Three sizes (227g, 480g, 1050g) of S. wangchiachii cultured at Jinping-Guandi fish breeding and releasing station in Yalong River were selected as the experimental objects. The composition of conventional nutrients, amino acids, fatty acids, and mineral elements in their muscle was determined, and amino acid nutrition was evaluated. The results showed average meat, meat water, crude fiber, and crude protein contents in the three sizes of S. wangchiachii muscle were 76.36 %, 76.21 %, 0.10 %, and 19.32 %, and there were no differences among them. Average crude fat and ash contents were 2.01% and 2.00%, and the contents were medium size > small size > large size. 18 amino acids (145.95 mg/g) and 8 essential amino acids (EAA) (58.16 mg/g) were detected in muscle, the contents of them were large size > small size > medium size. Six kinds of flavor amino acids (DAA) were determined, and their average was 71.86 mg/g, but the content of large size was significantly higher than that of the small and medium size. A total of 30 fatty acids were detected in the muscle of S. wangchiachii across the three sizes, comprising 11 saturated, 19 unsaturated, 9 monounsaturated, and 10 polyunsaturated fatty acids. The contents of both unsaturated and polyunsaturated fatty acids followed the order of small size > medium size > large size, with the average n-3 polyunsaturated fatty acid content reaching as high as 9.95 %. 9 mineral elements were detected, including 3 macro-elements and 6 micro-elements. The average content of zinc was as high as 9.04 mg/kg, but the average content of selenium was only 0.14 mg/kg. Compared with other common freshwater fishes, the contents of meat, crude protein, flavor amino acids, and unsaturated fatty acids in S. wangchiachii muscle were rich, and the contents of amino acids, fatty acids and minerals were high and reasonable. In summary, S. wangchiachii muscle was a kind of high-quality protein source, had good nutritional value and strong edible taste.
In order to analyze the ecological adaptability of fishes in the Lishui River, the absolute and relative critical swimming speed ( U c r i t a , U c r i t r ) and the bursting swimming speed ( U b u r s t a , U b u r s t r ) were measured for Dongtingking crucian carp ( Carassius auratus var. Dongting ) (body length 9.61±1.63 cm, body weight 18.26±1.14 g) and Plagiognathops microlepis (body length 10.28±1.17 cm, body weight 22.14±4.06 g) in the Changde section of the middle reaches of the Lishui River in Hunan Province of China at a water temperature of (21.0±0.5) ℃. These data were obtained by a custom-built fish swimming ability measuring device in the laboratory. The study analyzed the relationship between behavioral indices and body length (BL), as well as the differences in these indices between the two species. The results showed that for Dongtingking crucian carp ( Carassius auratus var. Dongting ) U c r i t a was (25.65±2.71) cm/s or U c r i t r (2.72±0.28) BL/s, and U b u r s t a was (22.46±2.31) cm/s or U b u r s t r (2.35±0.12) BL/s. For Plagiognathops microlepis , U c r i t a was (34.09 ± 2.15) cm/s or U c r i t r (3.31 ± 0.23) BL/s, and U b u r s t a was (30.2 ± 3.14) cm/s or U b u r s t r (2.93 ± 0.42) BL/s. According to the results, the linear and nonlinear function models of the critical swimming speed, the bursting swimming speed and body length of different fish were obtained. There were significantly higher U b u r s t a and U c r i t a of Plagiognathops microlepis than those of Carassius auratus var. Dongting by the paired t-test (P < 0.05), with the same significant differences between U b u r s t r and U c r i t r ( P <0.05). The morphological characteristics of the two typical fish in the Lishui River, such as body shape, bones, and fins were different, and conditions such as ecological position, eating habits, and feeding methods were also different, leading to great differences in their ability to swim. The results of this experiment enriched the database of swimming behavior characteristics of fish in the Lishui River and provided the basic data for the study of the adaptation mechanism of the typical fish movement in the physiology and ecology of the Lishui River.
Over the past few decades, aquaculture has consistently been the fastest-growing sector in global agriculture and remains a key provider of high-quality protein and nutritional support for the world’s population. China’s aquaculture industry has maintained its position as the world’s largest for many consecutive years, serving as an absolute pillar of the country’s fishery economy. Currently, China’s aquaculture industry is at a critical stage of transitioning from scale expansion to quality improvement, confronting multiple practical challenges during this transformation. Through policy review, literature analysis, field research, and industry data analysis, this paper identifies six major issues constraining the high-quality development of China’s aquaculture: conflicts between breeding rights and property rights; bottlenecks in key aquaculture technologies; imbalances in human resource structure; inadequate financial and insurance support systems; insufficient industrial chain robustness; and structural contradictions between new productive forces and the industrial ecosystem. Based on a comparison of international experiences, this paper proposes corresponding suggestions. By tracing the evolution of policies supporting high-quality aquaculture development and thoroughly analyzing current institutional, technical, and structural barriers, this paper attempts to establish a support system capable of fostering new productive forces and adapting to emerging demands. This research not only contributes to China’s food security and rural revitalization but also offers policy references for the sustainable development of global aquaculture.
Whitmania pigra (Whitman leech) is an aquatic annelid with extensive pharmacological activities. Erysipelas has severely affected the development of its artificial aquaculture industry. Astragalus polysaccharide (APS), as an immunopotentiator, is often used in aquaculture to enhance disease resistance of aquatic animals. However, the effect of APS on the intestinal microbiota of W. pigra remains unclear. In this study, 16S rDNA amplicon sequencing was used to explore the effects of APS on the prevention and control of “erysipelas” and the intestinal microbial community of W. pigra . The results showed that after injection with APS, the abundances of Bacteroidota and Firmicutes in the leech intestinal tract increased, while those of Proteobacteria decreased. At the genus level, the relative abundance of Bacteroides increased significantly. The results indicate that APS can optimize the intestinal microbial community structure of W. pigra , correct the imbalance in flora composition, thereby enhancing the body’s immunity and effectively preventing and controlling erysipelas, providing a theoretical reference for green prevention and control of disease in the aquaculture of this species.
To elucidate the toxic effects and adaptive mechanisms of copper stress on Ruditapes philippinarum, and to screen for sensitive biomarkers, this study established a 14-day stress experiment using the 48h median lethal concentration (LC50) of copper as a reference. Two treatment groups were established: 0.0568 mg/L (low concentration, 1/ 100 of 48h LC50) and 0.568 mg/L (high concentration, 1/10 of 48h LC50). Enzyme activity results showed that LDH, PK, and HK in the clams peaked on Day 2 and then slowly declined, indicating enhanced anaerobic respiration in the early stage of stress; SOD and CAT peaked on Day 7, reflecting the organism's response to oxidative stress during the middle stage; ACP first dropped to a minimum and then peaked in the middle-to-late stage, marking the activation of immune function in the later stage; TG and TCHO levels both showed a trend of initial decrease followed by an increase, indicating energy consumption for stress response in the early stage and adaptive regulation to maintain membrane function in the later stage; AKP showed no significant regularity. There were significant differences in core response indicators at different stages of copper stress: PK, HK, and LDH responded significantly in the initial stage; SOD and CAT responded strongly in the middle stage, serving as key indicators for the organism to resist oxidative damage; ACP, TCHO, and TG responded significantly in the later stage. Among them, LDH, SOD, ACP, and TG showed stable and prominent responses throughout the stress cycle and can be used as core biomarkers for assessing the toxic effects of copper pollution on Ruditapes philippinarum. Transcriptomic analysis indicated that the number of differentially expressed genes (DEGs) between the high and low concentration groups increased significantly with stress duration, reaching 5,337 (5,088 upregulated, 249 downregulated) on Day 14. GO and KEGG enrichment analyses revealed that the low-concentration group initiated rapid stress responses in material transport and fatty acid metabolism pathways in the early stage, activated antioxidant defense pathways in the middle stage, and coordinated multiple pathways to maintain homeostasis in the later stage. The high-concentration group resisted acute toxicity through lipid metabolism and mitophagy in the early stage, and strengthened detoxification, repair, and metabolic-immune coordinated regulation to adapt to long-term stress in the later stage. This study systematically elucidates the dynamic response patterns of Ruditapes philippinarum to copper stress., providing important physiological and molecular data support for heavy metal pollution monitoring and adaptive mechanism research in marine bivalves.
