To investigate the effects of a slightly acidic electrolyzed water (SAEW) treatment on the quality of fresh-cut apples during storage, this research used a Box–Behnken design to determine the optimal SAEW treatment conditions. Then, the fresh-cut apple was treated under the optimal condition and subjected to a 13-d storage experiment at 4 °C. For fresh-cut apple treated under the optimal SAEW treatment conditions, the total number of surface colonies was reduced by 2.82 logarithms compared to the control group and the sensory score was 8.73. For the treated fresh-cut apple during storage, the quality of the treated group was significantly greater than the non-treatment group. Thus, the SAEW treatment not only effectively controlled the number of microbes on fresh-cut apple, but also slowed quality deterioration during storage.

Temperature is a critical factor influencing fish health and aquaculture success. This study investigates the physiological, histological, and microbiota responses of juvenile Schizothorax grahami to chronic thermal stress across six temperature treatments. We found that exposure to temperatures exceeding 27 °C resulted in complete mortality in juvenile S. grahami, with the upper thermal tolerance range between 24 °C and 27 °C. Chronic thermal stress caused a significant decline in serum glucose (Glu), triglycerides (TG), and total cholesterol (TC) at 24 °C, indicating rapid energy depletion, while reduced serum enzyme activity of catalase (CAT) and total superoxide dismutase (T-SOD) at 24 °C group further reflected a decrease in antioxidant capacity. Histological examination revealed adaptive intestinal villus hypertrophy with increased length and muscularis thickness at temperature under 24 °C. Furthermore, the relative abundance of Cetobacterium and Fusobacteriota suggested either adaptive responses or stress-related dysbiosis that may contribute to weakened host immune function. Overall, our findings highlight the vulnerability of juvenile S. grahami to rising temperatures, with moderate thermal stress inducing adaptive responses, while higher temperatures impair metabolism, gut integrity, microbial health, and may even lead to lethality. These results underscore the need for effective conservation strategies to protect this critically endangered species in the face of climate change.

This study investigated whether these contrasting environments are associated with the development of coherent, organism-wide phenotypic–physiological syndromes reflecting a fundamental life-history trade-off. A controlled 60-day trial was conducted comparing crayfish from a high-input pond system (fed to satiation) and a low-input rice paddy system (primarily natural diet). Pond crayfish were fed a commercial formulated feed twice daily to satiation (approximately 3% of biomass per day). Rice paddy crayfish primarily consumed natural food webs and received a once-daily supplement of 30% of the pond feed amount (approximately 0.9% of biomass per day). Results revealed two distinct syndromes. Pond-cultured crayfish exhibited a growth-oriented syndrome: they were 33% heavier with a compact, volumetrically enhanced body shape, coupled with elevated lipid-anabolic enzyme activities (lipase and ACC), higher hemolymph protein and cholesterol concentrations, but also significantly increased levels of a stress-related endocrine factor (cortisol-like immunoreactivity) and oxidative damage (MDA). Conversely, rice paddy-cultured crayfish displayed a stress-resistance-oriented syndrome: a streamlined, deeper-abdomen morphology, fortified antioxidant (SOD, CAT, and GST) and immune (lysozyme and phenoloxidase) capacities, enhanced carbohydrate digestion (amylase), and lower systemic stress. Transcriptomic analysis showed that the hepatopancreas of paddy-cultured crayfish was enriched in pathways related to lipid metabolism, detoxification, and endocrine regulation, notably with upregulation of the SULT1E1 gene. Our findings demonstrate that the distinct environmental and nutritional conditions of each aquaculture system are linked to specific multi-level adaptation syndromes, presenting a clear trade-off between rapid biomass production and systemic stress resistance (within the 60-day trial period), providing a mechanistic basis for optimizing sustainable practices: integrated systems enhance stock robustness, while intensive systems require strategies to mitigate physiological load.

This study evaluated the effects of feeding juvenile southern catfish (Silurus meridionalis) with one of six isonitrogenous and isoenergetic diets where fish meal (FM) was replaced by black soldier fly larval meal (BSFLM) at 0%, 10%, 20%, 30%, 40%, and 50% levels on growth, muscle quality, antioxidant capacity, immune response, and gut microbiota of juvenile southern catfish (Silurus meridionalis). A total of 1620 fish (9.20 ± 0.15 g) were fed one of six experimental diets for 8 weeks. Results demonstrated that a 50% replacement (H50 group) significantly improved weight gain rate, specific growth rate, and protein efficiency ratio (p < 0.001). Antioxidant capacity (T-AOC) was enhanced in groups H30 and H50, while immune markers lysozyme (LZM) and alkaline phosphatase (AKP) showed mixed responses. Muscle texture properties such as chewiness and adhesiveness were significantly altered across treatments. Gut villi remained structurally intact in all groups, and liver histology appeared normal. No significant differences were found in muscle amino acid or fatty acid profiles. Gut microbiota analysis revealed shifts in microbial composition, with increased abundance of Clostridia and Escherichia and functional enrichment in metabolic pathways at higher substitution levels. Interspecies network analysis indicated potential cooperation among beneficial microbes through metabolite exchange. It is concluded that 50% BSFLM substitution optimizes growth performance, muscle quality, and antioxidant capacity, while modulating gut microbiota, indicating its promise as a sustainable FM alternative and functional ingredient in aquafeeds.

The red swamp crayfish is cultivated in intensive ponds and integrated rice–crayfish systems, which drive distinct growth-oriented versus stress-resistance syndromes, yet their metabolic underpinnings are unclear. We applied untargeted LC-MS metabolomics to hepatopancreas from both systems. Among 2681 metabolites, 566 were differentially abundant. Pond-cultured crayfish exhibited a lipid-centric anabolic metabolome (enriched ceramides, lysophosphatidylcholines, and free fatty acids) that supports rapid growth but incurs oxidative stress. Conversely, rice-paddy crayfish showed enhanced purine metabolism, aminoacyl-tRNA biosynthesis, and D-amino acid metabolism, reflecting energy mobilization and protein turnover under limited resources. Targeted assays confirmed significantly higher GSH/GSSG ratios (11.29 vs. 5.07) and lower MDA (3.07 vs. 5.00 nmol/mL) in rice-paddy crayfish, validating transcriptomic upregulation of glutathione biosynthesis. Integration with transcriptomic and phenotypic data revealed coherent trait–metabolite modules. Our findings suggest a trade-off between biomass production and systemic stress resistance, mediated by differential activation of purine and glutathione pathways, consistent with a growth–defense trade-off framework. This provides a mechanistic framework for sustainable aquaculture: integrated systems enhance robustness, whereas ponds require strategies to mitigate physiological load.