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.

The sustainable production of yellow catfish (Pelteobagrus fulvidraco) fry is critical for aquaculture, yet early developmental stages face high mortality and nutritional challenges. This study evaluated the effects of dietary supplementation with broken-cell wall P. rhodozyma on growth performance, organ development, enzyme activities, and gut microbiota composition in yellow catfish fry. Dietary supplementation with broken-cell wall P. rhodozyma significantly improved fry performance, increasing survival from 12% to 52%, promoting growth, enhancing intestinal and liver development, improving digestive enzyme activities, and modulating antioxidant-related physiological responses. It also elevated beneficial Muribaculum and reduced Streptococcus in the gut, promoting microbiota stability. These results demonstrate that P. rhodozyma supplementation not only improves early growth, organ maturation, stress resistance, and intestinal health but also effectively enhances overall fry health and development, thus supporting its use as a functional feed additive in aquaculture.

In this study, we investigated the effects of high temperature on plasma biochemical indicators and hematological parameters in blunt snout bream (Megalobrama amblycephala) following high-temperature stress. The fish (17.72 +/- 0.05 g) were exposed to two temperature conditions: a control group at ambient temperature (25 degrees C, measured temperature 25.25 +/- 0.34 degrees C) and a high-temperature treatment group (34 degrees C, measured temperature 33.07 +/- 0.26 degrees C). 6 fish were randomly sampled from each group at 0, 3, 6, 12, 24, and 48 hours. The results showed that high temperature significantly affects both plasma and hematological parameters. In the high-temperature group, both alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities initially increased and then decreased with prolonged stress duration. Alkaline phosphatase (ALP) activity reached its lowest point at 48 hours in this group(P < 0.05). Total protein (TP) and albumin (ALB) levels in the high-temperature group decreased significantly after 3 hours (P < 0.05). Glucose (Glu) levels in the high-temperature group increased significantly at 24 hours (P < 0.05). As stress duration increased, white blood cell count (WBC), red blood cell count (RBC), hemoglobin (HGB) levels, and hematocrit (HCT) in the high-temperature group all showed an upward trend. The results indicate that high-temperature stress induces pronounced stress responses, liver dysfunction, and adaptive alterations in blood oxygen-carrying capacity in blunt snout bream.

The widespread use of pesticides has raised serious concerns about their combined impact on aquatic life; however, the underlying mechanisms of reproductive toxicity remain poorly defined. Adult Japanese medaka (Oryzias latipes) were exposed for 60 days to fenvalerate (FEN, 0.039 mg/L), tebuconazole (TEB, 1.0 mg/L), or their combination (FEN + TEB, 0.01 mg/L + 0.5 mg/L) to evaluate single and mixture-induced disruption of the hypothalamic-pituitary-gonadal (HPG) axis. Long-term exposure to either FEN or TEB significantly reduced fertilization, hatchability, and survival rates, with the combined exposure group exhibiting the most severe adverse effects. Gonadal histological assessment revealed severe degenerative alterations, disrupted spermatogenesis, and reduction of germ cells, follicular atresia, and loss of structural integrity. Transcriptional profiling further demonstrated broad disturbances across the HPG axis, with significant downregulation of cyp19a1, dmrt1, fshr, gnrh1, gnrh2, lhβ, and star, alongside altered transcription of erα, erβ, fshβ, vtg1, and vtg2 in a sex-dependent pattern. The observed impairment of gametogenesis is likely attributable to dysregulated transcriptional control, as molecular docking revealed stable binding of FEN and TEB to Dmrt1 and aromatase (Cyp19a1). In addition, biochemical assays confirmed that co-exposure to FEN and TEB also led to oxidative stress and immune suppression, reflected by reductions in CAT, GSH-PX, LZM, and SOD activities and elevated MDA levels. These findings provide integrated molecular and histopathological evidence that FEN and TEB synergistically disrupt endocrine signaling, trigger oxidative imbalance, and impair gonadal integrity in fish, highlighting the ecological risks associated with pesticide mixtures in aquatic environments.

RhoA (Ras homolog A) is a prominent member of the Rho GTPase family, playing a key role in various cellular processes such as cytoskeletal dynamics, cell migration, and immune responses. However, its function in red swamp crayfish remains unclear. In this study, it is proposed that RhoA may regulate the innate immune response in P. clarkii. The gene was fully characterized as PcRhoA in P. clarkii. The results showed that the open reading frame (ORF) of PcRhoA is 663 bp, encoding a 220-amino acid protein with a conserved Rho domain of 174 amino acids. Phylogenetic analysis placed PcRhoA close to Cherax quadricarinatus RhoA. RT-qPCR analysis revealed high expression levels of the PcRhoA gene in the hepatopancreas, muscle, heart, ovary, and stomach, with lower expression in the blood, intestine, gills, and tentacle gland. Furthermore, PcRhoA mRNA transcript was significantly upregulated in the intestine following LPS and Poly I:C challenges. Knockdown of PcRhoA suppressed the expression of downstream genes in the immune signaling pathway. These results indicate that PcRhoA appears to play a pivotal role in regulating the immune response of crayfish.

Decapod iridescent virus 1 (DIV1) has severely restricted the development of Macrobrachium rosenbergii aquaculture, and safe and effective control agents are still lacking. This study targeted the viral major capsid protein (MCP) and used molecular docking to perform high-throughput virtual screening from a natural compound library containing 17,447 compounds, and finally obtained ten candidate compounds with binding energies ≤ −10 kcal/mol Using a short-term in vivo viral infection model established by artificial injection, top four compounds including Amentoflavone, Tectol, Polyphyllin II and Solamargine were screened out. In vivo assays demonstrated that all four candidates suppressed viral proliferation by over 90%. Notably, these compounds conferred significant protection against DIV1 infection in M. rosenbergii. Tectol exhibited the highest protective rate (71.25% ± 4.79%), followed by Amentoflavone and Polyphyllin II (both 55% ± 4.08%), and Solamargine (53% ± 2.16%), respectively. Subsequent validation trials demonstrated that the feeding M. rosenbergii with diets supplemented with these four compounds significantly reduced viral load and improved survival rate after DIV1 infection, while precisely and selectively regulating the expression of core genes in the interferon-like pathway (JAK, STAT, PIM3, IRF4, RSAD2, etc.) and key genes related to immune and energy metabolism (α2M, TPI, SAA5, PDGF, caspase-1, MRC1, etc.) in the M. rosenbergii. The results suggest that these compounds exert antiviral effects by directly inhibiting MCP protein and regulating host immunity, providing candidate molecules and a theoretical basis for the development of eco-friendly anti-DIV1 drugs for M.rosenbergii in aquaculture.

Environmental pH is a key factor affecting the nutritional quality of crayfish; its underlying mechanism remains unclear. This study preliminarily revealed the potential regulatory pathways underlying the effect of pH on the nutrient metabolism of crayfish through multi-omics analysis. The results showed that the contents of crude protein (18.03

Bisphenol S (BPS) is an emerging environmental contaminant that can disrupt oxidative and immune homeostasis in aquatic organisms, whereas myo-inositol (MI) is a water-soluble nutrient involved in growth and cellular signaling. This study evaluated growth, hepatopancreatic biochemical indices, and stress-related gene transcription in crayfish fed 0 or 1000 mg/kg supplemental MI and chronically exposed to 0–10 µg/L BPS for 6 weeks. Compared with the control group, the BPS group had significantly lower weight gain rate (WGR), specific growth rate (SGR), molting frequency, antioxidant enzyme activities (SOD, CAT, and POD), and immune enzyme activities (ACP, AKP, PO, and LZM), together with higher MDA content (P < 0.05). Compared with the BPS group, the MI + BPS group had significantly higher WGR, SGR, molting frequency, SOD, POD, ACP, and PO activities (P < 0.05). The MI + BPS group also showed higher nrf2 and hmc mRNA levels and lower keap1, bip, ire1, casp3, cytc, jnk, il-6, tnf-α, and nf-κb mRNA levels than the BPS group (P < 0.05). WGR, SGR, molting frequency, and hmc mRNA abundance in the MI + BPS group did not differ significantly from the control group (P > 0.05), the remaining endpoints showed indicator-specific responses. These findings indicate that dietary MI supplementation was associated with improved growth and selected antioxidant and immune indices, as well as altered transcription of genes related to oxidative, endoplasmic-reticulum-stress, inflammatory, and apoptosis-associated responses under BPS exposure. Pathway activation, tissue injury, and apoptosis were not directly assessed.

In order to reveal the molecular response characteristics of different tissues of Megalobrama amblycephala under ammonia nitrogen stress, the liver, gill, muscle, kidney and brain tissues of juvenile Megalobrama amblycephala (12.05 ± 0.04 g) under 25 mg/L ammonium chloride stress were used as the research objects. The transcriptome sequencing technology was used to systematically analyze the transcriptional expression changes. A total of 204.42 Gb transcription data were obtained, and a total of 3039 DEGs were detected, of which 1331 genes were up-regulated and 1708 genes were down-regulated. Ten DEGs were randomly selected for quantitative qRT-PCR analysis, and the results confirmed that the transcriptome results were reliable. Multi-organ synergy analysis suggested that overlapping DEGs (e.g., ZNF239, DMBT1, NLRC3, MHC-I, and CCL8) may exhibit similar or opposing regulatory patterns across organs, potentially reflecting complementary and coordinated mechanisms in immune regulation, inflammatory responses, energy allocation, and detoxification strategies among organ systems. GO and KEGG pathway enrichment analysis of differentially expressed genes showed that ammonia nitrogen mainly affected immune inflammation-related processes, material transport and degradation, protein homeostasis maintenance, oxidative stress defense, membrane lipid metabolism remodeling, and energy metabolism regulation. In different tissues, genes related to specific functions are enriched according to their physiological roles: in the liver, genes related to detoxification and damage clearance are enriched; in the gill, genes related to barrier defense and antioxidant/detoxification are enriched; in the kidney, genes related to damage response and metabolic regulation are enriched; in the brain, genes related to membrane lipid homeostasis and protective stress are enriched; and in the muscle, genes related to energy metabolism and structural function adjustment are enriched. This study elucidated the multi-tissue response characteristics of Megalobrama amblycephala under ammonia nitrogen stress at the transcriptome level, providing fundamental data and references for further clarifying the mechanisms of ammonia nitrogen toxicity in fish and screening stress-responsive marker genes.

Enteritis is a disease that affects Procambarus clarkii, significantly impacting aquaculture due to its high incidence and mortality rates, resulting in economic losses. Currently, the molecular mechanisms behind enteritis in Procambarus clarkii are not well understood. In this study, we established a model of intestinal inflammation induced by dextran sodium sulfate (DSS). Subsequently, histopathological changes, transcriptome analysis, intestinal microbiota analysis and immunofluorescence analysis were conducted. Histopathology showed that after treatment in the DSS + Narirutin (NR) group, there was an improvement in intestinal inflammation, and the structure of the intestinal tissue was partially restored. The intestinal transcriptome analysis revealed that in the DSS + NR group, 234 genes were upregulated and 188 genes were downregulated after treatment. This indicates a significant change in gene expression. KEGG enrichment analysis revealed that the DEGs were significantly enriched in TGF-beta signaling pathway and PI3K-Akt signaling pathway. The results from 16S rRNA sequencing showed that in the DSS + NR group, the relative abundance of Akkermansia muciniphila significantly increased. Immunofluorescence results showed that, compared to the control group, the expressions of Occludin, nuclear factor-kB-p65 (NfkB-p65), Zonula occludens-1 (ZO-1), and Claudin-1 decreased following DSS treatment. However, treatment with NR was able to inhibit these changes. This further validated that NR can alleviate enteritis in Procambarus clarkii.

The protein-to-energy ratio is crucial for the overall performance of Macrobrachium rosenbergii postlarvae, yet the optimal range remains undetermined. We formulated nine experimental diets in a 3 & times; 3 factorial design, encompassing three graded protein levels (45.83%, P46; 49.03%, P49; 52.23%, P52) and three graded lipid levels (6.07%, L6; 8.03%, L8; 10.03%, L10). After an 8-week feeding trial, the weight gain rate (WGR) was influenced by both protein and lipid levels, with a peak in the P49/L8 group (p < 0.05). Their interaction significantly affected hemolymph superoxide dismutase (SOD) and malondialdehyde (MDA) levels (p < 0.05). SOD initially increased and then decreased with increasing protein level, peaking in the P49/L8 group (p < 0.05). Total antioxidant capacity (T-AOC) decreased with increasing lipid level but showed an initial increase followed by a decrease at the P52 level, reaching its highest value in the P52/L8 group (p < 0.05). At low lipid levels, trypsin increased with increasing protein, whereas it decreased at high lipid levels. Lipase initially increased and then decreased with increasing levels of both protein and lipid, reaching its peak in the P52/L8 group (p < 0.05). The relative lipid droplet area increased with increasing protein and lipid levels, reaching a maximum in the P52/L10 group (p < 0.05). Appropriate protein level significantly activated the TOR/S6K1 pathway, while elevated lipid levels upregulated genes related to lipid synthesis (FAS and ACC) and transport (fatty acid-binding protein [FABP]), while downregulating genes associated with lipid breakdown. In conclusion, the optimal dietary protein and lipid levels for postlarval M. rosenbergii are 49% and 8%, respectively, corresponding to a P/E ratio of 29.34 mg protein & centerdot;kJ(-1).

The high protein content of Oncorhynchus mykiss, despite its nutritional value, poses a risk of microbial contamination and foodborne illnesses in fresh products, thus necessitating paramount importance for effective preservation. In this study, a synergistic preservation system possessing both antimicrobial and antioxidant functions was developed from pomelo peel. Enzyme-like material with peroxidase-like activity (K/Fe-PP) were synthesized from pomelo peel, KCl and FeCl 3 via a hydrothermal method. These enzyme-like materials catalyze the continuous generation of hydroxyl radicals (square OH) from H 2 O 2 , enabling sustained bacterial inhibition. An ethanol extract of pomelo peel, harnessing the strong reducing power of its enriched phenolic compounds, was used to inhibit lipid oxidation in fish. To realize their synergy, the K/Fe-PP and the pomelo peel extract were added into a chitosan matrix, which served as a carrier, and were subsequently fabricated into a composite cling film (CS/K/Fe-PP).CS/K/Fe-PP films were applied to Oncorhynchus mykiss under refrigerated storage. The spoilage of Oncorhynchus mykiss was assessed by the value of malondialdehyde (MDA), acid value, total volatile basic nitrogen (TVB-N), histamine content, and total viable count (TVC). It was shown that the optimal cling film extended the storage time of Oncorhynchus mykiss by 3-6 days. This work not only provides a new strategy for applying catalysis based on enzyme-like materials in aquatic product preservation but also establishes a sustainable approach for the high-value utilization of waste biomass resources.

High-fat diets are commonly used in crustacean aquaculture to reduce protein costs, but excessive fat intake can impair growth and health. This study investigated whether lysophosphatidylcholine (LPC), an emulsifying additive, is associated with the mitigation of negative effects of high-fat diets in crayfish (Procambarus clarkii). A total of 600 crayfish (4.00g) were randomly divided into four groups with three replicates: control (CK, 6.70% fat), high-fat diet (HFD, 10.21% fat), and HFD supplemented with 38.75mg/kg (LPD) and 82.54mg/kg LPC (HPD) for six weeks. Results showed that crayfish given a high-fat diet presented considerable decreases in final average weight, specific growth rate, and weight gain rate (P < 0.05), coupled with an increase in hepatosomatic index (P < 0.05). Supplementing with LPC helped alleviate hepatopancreas damage induced by high-fat diets, as demonstrated by reduced vacuolization and lower malondialdehyde level, along with decreased aminotransferase activities (P < 0.05). LPC also enhanced antioxidant capacity (increased glutathione, P < 0.05) and suppressed key lipid metabolism enzymes (P < 0.05), indicating reduced hepatic lipid accumulation. Further microbial profiling presented that LPC supplementation co-occurred with a restored microbial balance, characterized by reduced Proteobacteria (Citrobacter, Pseudomonas) and increasing Firmicutes (Tyzzerella), and a predicted suppression of lipopolysaccharide biosynthesis. These findings suggest that dietary LPC effectively counteracts high-fat diet-induced growth decline, hepatopancreas damage, which is associated with restructuring of the gut microbiota and suppression of harmful metabolic pathways. Our results provide a correlative basis and generate the hypothesis that LPC may exert its beneficial effects through microbiota modulation, warranting further mechanistic validation.

Crayfish with cyan soft-carapace and red hard-carapace differ considerably in market value. To investigate the causes underlying this difference in shell color, we selected 120 healthy Procambarus clarkii of similar size (9–10 cm), equally divided by shell color and sex. Muscle quality, pigment deposition, and DGAT2 mRNA expression were compared between the two shell-color types. The results showed that: (1) Muscle hardness was significantly higher in red hard-carapace crayfish than in cyan soft-carapace crayfish (p < 0.05), whereas no significant difference in muscle elasticity was observed among groups (p > 0.05). (2) A significant interaction between shell color and sex influenced crude fat and ash content (p < 0.05). Crude fat content was higher in red hard-carapace crayfish, and ash content was highest in male red hard-carapace crayfish, significantly exceeding that in male cyan soft-carapace crayfish (p < 0.05). (3) Moisture and crude protein content were not significantly affected by the interaction between shell color and sex (p > 0.05), with no notable differences across groups. (4) The contents of astaxanthin, lutein, and β-carotene in the shell were significantly influenced by the interaction between sex and shell color (p < 0.05). Astaxanthin was lowest in female cyan soft-carapace crayfish, and lutein was highest in male red hard-carapace crayfish, and β-carotene showed no significant differences. (5) DGAT2 mRNA expression was highest in hepatic tissue across all groups (p < 0.05). In gonads, expression was higher in ovaries of cyan soft-carapace crayfish and in testes of red hard-carapace crayfish (p < 0.05). (6) DGAT2 mRNA expression in the inner membrane, muscle, and intestine was significantly affected by the interaction between shell color and sex (p < 0.05), with specific expression patterns varying among tissues and groups. These findings indicate that shell color and sex interact to influence nutritional composition, carotenoid profile, and gene expression, providing insights into the mechanisms of body color formation and its physiological correlates.

This study evaluated the impact of berberine (BBR) supplementation on growth, immune function, antioxidant capacity, and glucose metabolism in Procambarus clarkii fed a high-carbohydrate diet (HCD). Crayfish were assigned to three groups: a normal-carbohydrate diet (NCD, 33%), HCD (41%), and HCD with 50 mg/kg BBR (HCB). After an 8-week trial, no significant differences were observed in growth performance or body composition. However, BBR supplementation significantly improved antioxidant capacity by restoring superoxide dismutase (SOD) activity and reducing levels of malondialdehyde (MDA) and glutathione peroxidase (GSH-Px). BBR also mitigated HCD-induced hyperglycemia and hypertriglyceridemia, while increasing hepatic glycogen content and promoting glycolytic enzyme activities (pyruvate kinase and hexokinase). Additionally, BBR elevated the expression of glycogen synthase and glycolysis-related genes (HK, PK, PFK) and decreased gluconeogenesis markers (G6P, PC). These findings suggest that BBR improves glucose metabolism and antioxidant defenses without negatively affecting growth in crayfish fed a high-carbohydrate diet. The abstract graphic is shown in Supplementary Fig. S1.

Taurochenodeoxycholic acid (TCDCA), one of the bile acids, is thought to be involved in the regulation of muscle nutrient metabolism and gut microbial homeostasis. However, the effect of dietary addition of TCDCA on Procambarus clarkii is unclear. Therefore, in this study, an 8-week feeding experiment was conducted to explore the potential regulatory mechanisms of TCDCA on P. clarkii growth, physiology, muscle quality and gut microbes. The results indicated that dietary addition of TCDCA not only improved growth performance (final weight; weight gain; and specific growth rate) but also increased muscle elasticity and protein content. In addition, dietary TCDCA promotes muscle growth and development by increasing myofiber length, which is consistent with the activation of the expression of genes related to protein utilization (TOR and AKT) and muscle proliferation and differentiation (MyHC, MLC1, MEF2A, MEF2B). Importantly, 16s rRNA sequencing demonstrated that dietary TCDCA had no significant effect on gut microbial composition (alpha diversity) but significantly increased microbial abundance at the genus level. Functional prediction analysis of differential microbes revealed that dietary TCDCA may promote metabolism by altering gut microbes, thereby promoting muscle quality. In conclusion, our study demonstrates that the dietary addition of TCDCA promotes P. clarkii growth and muscle quality and protein deposition by altering gut microbes.

While commercial diets for Chinese mitten crabs provide a diverse range of nutrients, they still have certain limitations compared to feeding with frozen trash fish (FTF), such as poor water stability. Most studies have focused on optimizing dietary formulations to address this issue, overlooking the influence of the physical properties of the diet on Eriocheir sinensis. In this study, a novel sodium alginate-based hydrogel (SAH) diet was developed to investigate the effects of its soft particle texture on the growth and digestion of E. sinensis. Growth experiment: Crabs were fed three diets with different textures-FTF, pellet diet (PED), and SAH (SA12.5 %)- over an 8-week period. The initial average weight of each group was 75.3 +/- 0.75 g. No significant differences in growth performance were observed among the three diet groups. The analysis of digestive enzyme activity in the hepatopancreas showed a notable increase in trypsin activity in the SAH group compared with the FTF group, while lipase, alpha-amylase, and cellulase activities showed no significant differences. The examination of digestion-related gene expression in the intestine revealed notable upregulation of crtb1, il, espt, pm1, and pm2 genes in the SAH group. Additionally, gut microbiota diversity increased, whereas richness decreased in the SAH group. Apparent digestibility test: Five SAH diets with varying SA (SAH1 [SA8.33 %], SAH2 [SA9.09 %], SAH3 [SA10 %], SAH4 [SA11.01 %], and SAH5 [SA12.5 %]) were tested, with PED serving as the control (CON). The apparent digestibility of dry matter, crude protein, crude lipid, total phosphorus, and total amino acids in SAH3 and SAH5 groups was significantly higher than that in the CON. In conclusion, the SAH diet improved the digestive performance of E. sinensis without adversely affecting growth, leading to notable improvements in digestive enzyme activity and apparent digestibility.

Astragalus and ginseng, esteemed as traditional Chinese herbal medicines, have demonstrated the ability to bolster physical health and enhance the immune function of organisms. In this study, the effects of a dietary astragalus–ginseng mixture on the growth performance, intestinal health, and nonspecific immunity of yellow catfish (Pelteobagrus fulvidraco) were evaluated, by measuring growth performance indices, intestinal villus morphology, enzyme activities, and expression levels of immune-related genes. Yellow catfish (n = 120, initial weight: 5.07 ± 0.18 g) were randomly assigned to four dietary groups: a control group (CT, 0 mg/kg) and three astragalus–ginseng treatment groups (AG1, 500 mg/kg; AG2, 1000 mg/kg; AG3, 2000 mg/kg). Each group had three replicates and was fed for six weeks. The results demonstrate that the treatment significantly enhanced the growth performance, as evidenced by increases in FBW, WG, WGR, SGR, and HSI. These improvements may be related to an increase in intestinal villi length and increased LPS activity, both of which are associated with enhanced digestive function. Meanwhile, the activity of antioxidant enzymes in the liver, including CAT, SOD, and GSH, was increased, whereas the level of MDA was decreased. In the serum, GSH was up-regulated, while SOD activity was decreased. Immune-related enzyme activities, such as ALT and LZM, were up-regulated, while AST showed no significant difference. Moreover, the treatment also promoted the expression of the anti-inflammatory factor IL-10. The pro-inflammatory factors, such as IL-1β, IL-6, and TNF-α, were decreased with the addition of low concentrations but increased with high concentrations. In conclusion, supplementation with an astragalus–ginseng mixture could promote growth performance by increasing digestive enzyme activity and intestinal villi length, and improve disease and stress resistance traits by modulating immune genes and antioxidant enzyme activity. A dosage of 1000 mg/kg was found to be optimal.

Environmental pesticides such as fenvalerate (FEN) and tebuconazole (TEB) frequently co-occur in aquatic ecosystems, yet their combined impacts on gut-liver immune communication remain poorly understood. This study evaluated the chronic toxicity of FEN (0.029 mg/L), TEB (1 mg/L), and their mixture (0.01 mg/L FEN + 0.5 mg/L TEB) in adult Japanese medaka (Oryzias latipes) through an integrative approach encompassing histopathology, biochemical assays, gut microbiota profiling, and hepatic transcriptomics. Co-exposure induced significant (p < 0.05) intestinal pathology characterized by epithelial degeneration, compromised barrier integrity, and suppression of digestive and immune enzyme activities. Corresponding hepatic alterations were also significant (p < 0.05), including vacuolization, inflammatory infiltration, oxidative stress, and activation of apoptosis-related signaling pathways. Gut microbiome analysis revealed pesticide-induced dysbiosis correlated with transcriptomic changes in hepatic lipid metabolism and immune regulation, suggesting that microbial imbalance may contribute to hepatic dysfunction through gut-liver axis communication. Molecular docking further indicated that tebuconazole (TEB) exhibited a stronger binding affinity to apoptotic proteins P53 and Caspase-3 than fenvalerate (FEN), consistent with the observed upregulation of apoptosis-related genes. Collectively, this study highlights the immune-metabolic toxicity of pesticide mixtures and identifies molecular and microbial signatures relevant to environmental risk assessment.

This study was conducted to evaluate the changes in amino acid metabolism and amine deposition in Chinese mitten crab (E. sinensis) fed with a diet containing Trimethylamine N-oxide (TMAO) to promote its growth and flavor. Three diets containing 0% TMAO, 0.01% TMAO, and 0.04% TMAO were designed respectively for E. sinensis (37.50 ± 0.5 g) for 15 weeks. According to the results, two experimental groups with TMAO had significant decrease in feed conversion ratio and feed intake (p < 0.05) while it showed the opposite trend in the enzyme activity of trypsin. With the addition of TMAO, the value of umami in muscle increased significantly (p < 0.05). Compared with the other two groups, the 0.04% TMAO group showed a significant increase in TMAO deposition and the content of methionine in the muscle (p < 0.05). Meanwhile, the deposition of spermidine and spermine significantly decreased in this group (p < 0.05). When feeding crabs with the diet containing 0.01% TMAO, the relative gene expression of S6K1 and eIF4E increased significantly while 4E-BP1 decreased markedly (p < 0.05). The protein expression of mTOR in muscle showed an upward trend in the 0.01% TMAO group. In summary, 0.01% TMAO in the diet could improve the FCR by increasing the enzyme activity of trypsin and improving growth performance by activating the mTOR pathway. 0.04% TMAO could increase the value of umami and the deposition of TMAO in muscle.