Search Results (149)

Medium-chain fatty acid triglycerides (MCTs) possess antibacterial, antiviral, nutritional, and other biological activities and have demonstrated significant application potential in humans and terrestrial animals. In recent years, with the development of the green aquaculture industry, MCTs have been gradually applied to aquaculture animals, which can enhance growth performance, improve flesh quality, regulate lipid metabolism, boost immune activity, and modulate the intestinal flora, thereby improving the production efficiency of aquaculture. This paper elaborates in detail on the biological activities of MCTs and their applications in aquatic animals, providing a theoretical and practical basis for the application of MCTs in aquaculture. Full article

The ecological rice–eel co-culture system is not only beneficial for enhancing productivity and sustainability in agriculture but also plays a crucial role in promoting environmental health. In the present study, based on the long-term positioning trial of the rice–eel co-culture system that began in 2016 and was sampled in 2023, the effects of reduced nitrogen fertilizer application on soil physico-chemical properties and the bacterial community were investigated. Treatments included a conventional regular fertilization treatment (RT), rice–eel co-culture system regular fertilization (IT), and nitrogen-reduction 10%, 30%, and 50% fertilization treatments (IT90, IT70, and IT50). Our research demonstrated the following: (1) Compared to RT, IT significantly increased soil water-stable macroaggregates (R0.25), mean weight diameter (MWD), geometric mean diameter (GMD), and available phosphorus content, with the increases of 15.66%, 25.49%, 36.00%, and 18.42%, respectively. Among the nitrogen-reduction fertilization treatments, IT90 showed the most significant effect. Compared to IT, IT90 significantly increased R0.25, MWD, GMD, and available nitrogen content, with increases of 4.4%, 7.81%, 8.82%, and 28.89%, respectively. (2) Compared to RT, at the phylum level, the diversity of Chloroflexi was significantly increased under IT and IT50, and the diversity of Gemmatimonadota was significantly increased under IT90, IT70, and IT50. The diversity of Acidobacteriota was significantly higher in IT90 and IT70 compared to IT. It was shown that the rice–eel co-culture system and nitrogen fertilizer reduction could effectively improve the degradation capacity of organic matter and promote soil nitrogen cycling. In addition, redundancy analysis (RDA) identified total phosphorus, total nitrogen, and available nitrogen (p = 0.007) as the three most important environmental factors driving changes in the bacterial community. (3) The functional prediction analysis of soil microbiota showed that, compared to RT, the diversity of pathways related to biosynthesis (carbohydrate biosynthesis and cell structure biosynthesis) and metabolism (L-glutamate and L-glutamine biosynthesis) was significantly higher under IT70, IT90, IT, and IT50 (in descending order). However, the diversity of pathways associated with degradation/utilization/assimilation (secondary metabolite degradation and amine and polyamine degradation) was significantly lower under all the rice–eel co-culture treatments. In conclusion, the rice–eel co-culture system improved soil physicochemical properties and the soil microbial environment compared with conventional planting, and the best soil improvement was achieved with 10% less N fertilizer application. Full article

A 56-day trial was conducted to assess the effects of rice straw (RS) and bamboo flour (BF) on growth performance, water quality, gill histology, and the bacterial community of water and the intestine of mandarin fish (Siniperca chuatsi) in biofloc technology systems. The results showed that mandarin fish in the RS and BF groups had comparable survival rates of 100.00 ± 0.00 and 93.33 ± 3.85%; feed conversion ratios of 1.13 ± 0.02 and 1.40 ± 0.15; and weight gain rates of 112.21 ± 1.56 and 100.92 ± 6.45%, respectively. From days 11 to 56 of the farming period, the BF group was more effective than the RS group in removing total ammonia nitrogen (TAN) and NO₂⁻-N, maintaining TAN levels below 0.24 ± 0.05 mg/L. During the early stage of the experiment, the TAN level in the RS group was higher; however, with the supplementation of a carbon source, it gradually decreased and eventually stabilized at 0.13 ± 0.03 mg/L later in the farming period. The secondary gill lamella in the RS group was curved and showed hyperplasia, and the basal gill lamellae showed an increase in the volume of interlamellar cell mass in the BF group. Genes related to denitrification (narG, napA, nirS, nirK, and nosZ) and anammox showed higher expression levels in the BF group than in the RS group, although the differences were not statistically significant (p > 0.05). The results of 16S rRNA sequencing research showed that both treatment groups’ intestinal and water bacterial communities had comparable levels of richness and diversity. Pseudomonas mosselii was the dominant bacterial species in the water. In the BF group, the dominant intestinal species were Bacillus halodurans and Caldalkalibacillus thermarum, while in the RS group, the dominant species was Plesiomonas shigelloides. In conclusion, rice straw and bamboo flour are applicable in BFT systems for mandarin fish culture, with good growth performance and water quality. The BF group showed higher nitrogen removal efficiency and denitrification gene expression than the RS group. Full article

As consumer demand for quality fish products continues to rise, quality has become a key factor in market competition. Ecological aquaculture research is exploring various farming methods to balance high-quality demand with environmental protection. This study compared three aquaculture models—cage culture (CG), recirculating aquaculture (RAG), and rice–fish co-culture (RG)—by analyzing muscle quality (AOAC, GC-MS), intestinal microbiota (16S rRNA), and liver metabolism (LC-MS) to assess their effects on M. albus. In terms of muscle quality, the RG group showed increased levels of EPA and DHA, reduced muscle moisture and crude lipid content, and enhanced crude protein accumulation. The crude protein content was significantly higher in the RAG group than in the CG group (p < 0.05). The RG group also had the highest levels of total, essential, and umami amino acids, followed by the RAG and CG groups. In terms of intestinal microbiota, the RG group had the highest microbial diversity and stability, with increased abundance of Firmicutes and Bacteroidetes and decreased levels of Proteobacteria. Compared to the CG, the RAG group also showed increased microbial diversity and a reduction in pathogenic genera. Liver metabolomics analysis demonstrated that the RG group had significant advantages over the CG group in amino acid, lipid, and energy metabolism. The RAG group exhibited upregulation of glycerophospholipid metabolism and a decrease in oxidative stress marker levels. Overall, the RG group enhanced muscle quality and optimized intestinal and liver metabolism in M. albus. Full article

Integrated agriculture–aquaculture (IAA), represented by integrated rice–fish farming, offers a sustainable production method that addresses global food issues and ensures food security. Partitioned recirculating renovation based on traditional integrated rice–fish farming is an effective way to facilitate the convenient harvesting of aquatic products and avoid difficulties associated with mechanical operations. To elucidate the impact of partitioned recirculating renovation on the bacterial communities within paddy field ecosystems, we investigated the soil environmental conditions and soil bacterial communities within integrated rice–fish farming, comparing those with and without partitioned recirculating renovations. The findings indicated a significant reduction in the bacterial community richness within paddy soil in the ditch (fish farming area), along with noticeable changes in the relative proportions of the predominant bacterial phyla in both the ditch and the rice cultivation area following the implementation of partitioned recirculating renovation. In both the ditch and the rice cultivation area, partitioned recirculating renovation diminished the edges and nodes in the co-occurrence networks for soil bacterial communities and considerably lowered the robustness index, negatively impacting the stability of bacterial communities in paddy soil. Simultaneously, the partitioned recirculating renovation substantially influenced the bacterial community assembly process, enhancing the relative contributions of stochastic processes such as dispersal limitation, drift, and homogenizing dispersal. In addition, partitioned recirculating renovation significantly altered the soil environmental conditions in both the ditch and the rice cultivation area, with environmental factors being markedly correlated with the soil bacterial community, especially the total nitrogen (TN) and total phosphorus (TP), which emerged as the primary environmental drivers influencing the soil bacterial community. Overall, these results elucidated the ecological impacts of partitioned recirculating renovation on the paddy soil from a microbiomic perspective, providing a microbial basis for optimizing partitioned rice–fish systems. Full article

Grass carp (Ctenopharyngodon idella), a globally important aquaculture species, exhibits protein-dependent growth plasticity, requiring genetic improvement for sustainable production. This study integrates genome-wide association analysis (GWAS) and genomic selection (GS) to unravel the genetic architecture of four growth traits, body weight, body length, body height, and body depth, in grass carp fed with diets of varying protein levels (20%, 25%, 30%, and 35%). Using a 21K liquid SNP array, we identified 62,736 high-quality SNPs across 24 chromosomes, with 90 SNPs significantly associated with growth traits. Notably, three SNPs (SLG14_24417024, SLG14_24417039, SLG24_30276273) exhibited pleiotropic effects on multiple traits. Functional annotation of 276 candidate genes near significant SNPs revealed enrichment in keratinocyte development, septin cytoskeleton organization, and heat acclimation pathways. Genomic prediction achieved accuracies up to 0.79 for body weight traits using 1533 optimal markers. This study provides the first comprehensive SNP resource for grass carp growth traits with different dietary treatments, bridging GWAS and genomic prediction to accelerate marker-assisted selection. Our findings not only advance genetic breeding strategies but also inform protein diet optimization, minimizing economic and environmental costs in aquaculture. Full article

China leads global carp aquaculture (farming of species within the family Cyprinidae), producing 20 million tons annually in a sector shaped by favorable policies, infrastructure, and innovation. Carp farming in China is rooted in millennia of traditional practices and transformative post-1978 economic reforms. This review synthesizes the historical trajectory, technological advancements, policy frameworks, and sustainability challenges shaping China’s carp aquaculture sector. Historically, carp polyculture systems, developed during the Tang Dynasty (618–907 CE), laid the foundation for resource-efficient practices. Modern intensification, driven by state-led policies, genetic innovations, and feed-based systems, enabled unprecedented growth. However, rapid expansion has exacerbated environmental trade-offs, including nutrient pollution, habitat loss, and antibiotic resistance, while socioeconomic disparities, aging labor forces, and market volatility threaten sectoral resilience. Policy shifts since the 2000s prioritize ecological sustainability, exemplified by effluent regulations, wetland restoration, and green technologies. Despite progress, challenges persist in reconciling economic viability with environmental safeguards. Key success factors include long-term policy support, smallholder capacity building, vertically integrated supply chains, product differentiation, and adaptive management. With balanced policies emphasizing economic, social, and environmental sustainability, carp aquaculture can enhance domestic food and nutrition security. China’s experience showcases the potential of aquaculture to bolster food security but highlights the urgent need to harmonize productivity with ecological and social equity to ensure long-term resilience. Lessons from China’s model offer actionable insights for global aquaculture systems navigating similar sustainability imperatives. Full article

Gibel carp (Carassius auratus gibelio) were hypoxia stressed for 12 h after an 8-week FPR nutrient-enriched feeding experiment, which was to evaluate the role of FPR in hypoxic stress in gibel carp (Carassius auratus gibelio). The dissolved oxygen was reduced to a range of 0.6 ± 0.2 mg/L. Results showed that FPR supplementation could maintain the osmotic pressure equilibrium by improving the ion concentrations of plasma including Na⁺, Ca⁺ and K⁺, and Na⁺/K⁺-ATPase activity of liver. FPR supplementation could effectively enhance the antioxidant capacity by improving the levels of GPX, SOD, CAT, and GSH, and reduce the level of MDA. FPR supplementation could improve the core gene expressions of Nrf2 signalling pathway including nrf2, sod, ho-1, gpx, and cat. The high levels of FPR supplementation (0.04%) might had a negative effect on immunity. FPR supplementation could improve the expression levels of HIF-1 signalling pathway-related genes to adapt to hypoxia condition including hif-1α, epo, angpt1, vegf, et1, and tfr-1. These results also were supported by higher SR and number of gill mitochondria in FPR supplementation. In general, the appropriate FPR supplementation was 0.01% based on the results of this study and economic cost, which could heighten hypoxic adaptation and SR. Full article

This study aimed to evaluate the impact of Eucommia ulmoides extract (EE) supplementation on the expression of genes related to glucose metabolism and antioxidant capacity of M. salmoides in response to different starch levels. In order to evaluate the effect of EE on fish metabolism and especially to enhance the metabolism of M. salmoides towards glucose metabolism, especially in high and low starch formulations, we designed six experimental feed groups: PC (high-starch control), NC (low-starch control), and four groups supplemented with EE on the basis of PC, with EE concentrations of 0.05%, 0.10%, 0.15%, and 0.20%, respectively. Each feed was administered to fish with an average weight of 36.98 ± 0.08 g, which were cultured for seven weeks, and the water temperature was 31–33 °C. The results demonstrated that increasing the EE concentration in the feed significantly influenced fish growth without affecting the body composition. Regarding the antioxidant activity, the highest CAT (catalase) enzyme activity in the intestine was recorded in the 0.15% EE group. Additionally, the mRNA expression of the antioxidant gene keap1 (kelch-like ECH-associated protein1) increased with higher EE supplementation, and sod (superoxide dismutase) mRNA expression was significantly elevated in the 0.10% EE group compared to that in the PC group. A plasma biochemical analysis revealed a significant increase in the ALP (alkaline phosphatase) activity in the 0.05% EE group relative to the PC group, while the TG (triglycerides) levels progressively decreased as the EE levels increased. Furthermore, the GLU (glucose) levels were significantly reduced in both the EE-supplemented and NC groups compared to those in the PC group. Among the genes associated with glucose metabolism, both gk (glucokinase) and pepck (phosphoenol pyruvate carboxykinase) exhibited a pattern of initially decreasing, followed by an increase, as the EE levels rose, with the pepck (phosphoenol pyruvate carboxykinase) expression being lowest in the 0.10% EE group. In conclusion, appropriate EE supplementation in the diet may promote growth performance, enhance antioxidant capacity, and support the expression of genes related to glucose metabolism of M.salmoides in response to different starch levels. Full article

Integrated rice–fish farming, crucial for sustainable agriculture, relies on the judicious use of pesticide. This study evaluates the toxicity of six common rice-field pesticides on Procypris merus (rice flower carp), a key species in these systems. We conducted acute and chronic toxicity tests, assessing survival, growth, oxidative stress (SOD, CAT, MDA, 8-OHdG), and neurotoxicity (AChE). Results revealed a spectrum of toxicity: abamectin and trifloxystrobin were highly toxic; pretilachlor was moderately so; and glufosinate-ammonium, triflumezopyrim, and thiazole zinc were low. Notably, triflumezopyrim induced significant oxidative stress and DNA damage, while all three low-toxicity pesticides inhibited AChE activity, indicating potential neurotoxicity. Despite these effects, all observed toxicities were reversible within 7–14 days. Considering that the tested concentrations exceeded typical field application rates, glufosinate-ammonium, triflumezopyrim, and thiazole zinc are deemed relatively safe for P. merus at recommended dosages. Our findings provide critical insights for optimizing pesticide selection in rice–fish farming, balancing pest control with ecological safety, thereby informing sustainable agricultural practices. Full article

The Chinese mitten crab, Eriocheir sinensis, is a water-dwelling crustacean that is widely distributed in northern hemisphere water systems. Body size is one of the crucial indicators determining the economic value of E. sinensis. However, research on the genetic basis and regulatory mechanisms of body size in this species is limited, with only a few relevant genes reported. Therefore, it is imperative to investigate the regulatory pathways associated with its growth. This study first utilized transcriptomic profiling and metabolomic sequencing to construct gene expression profiles and metabolite profiles of E. sinensis of different body sizes. Subsequently, through integrated omics analysis, the key genes and regulatory pathways involved in controlling the growth and size of crabs were preliminarily identified. This study found that larger female crabs exhibited significantly enhanced digestive functions, primarily reflected in the upregulation of trypsin-1 expression, suggesting its potentially pivotal role in regulating the growth and development of crabs. Interestingly, a variety of tissue-specific proteins such as APOLPP, RICK A, AGMO, and NEPHRIN, as well as REXO1L1P and ZCCHC24, indirectly influence the growth and development of crabs through their respective functional pathways. In addition, the key KEGG pathways, such as ECM–receptor interaction, cell adhesion, and the PI3K-Akt signaling pathway, were revealed to play central roles in the growth regulation of E. sinensis. These findings expand our understanding of the growth regulation mechanisms in crustaceans and offer potential molecular targets for body-size improvement in aquaculture. Full article

The Asian eel, a medicinal and edible species, lacks systematic research on age-related nutritional and flavor dynamics. To optimize breeding strategies and product differentiation, this study systematically investigated the nutritional composition, flavor profiles, and physical properties of Asian eel muscles across five distinct growth stages (1, 3, 7, 11, and 22 years). Results showed that unsaturated fatty acids increased with age, while ω-3/ω-6 ratios peaked in 1-year-old eels. The levels of hydrolyzed essential amino acids were higher in the 3–11-year-old groups, contrasting with higher free amino acids in 1- and 22-year-old eels. Texture declined in hardness/chewiness but improved in resilience with age, linked to muscle fiber density and diameter. One–three-year-old eels exhibited compact muscle fibers and superior texture, while 7–22-year groups demonstrated functional lipid profiles (high docosahexaenoic acid and γ-aminobutyric acid, low cholesterol). These findings highlight age-specific quality traits: 1–3-year-old eels are suitable for fresh consumption, 3–11-year groups offer bioactive benefits, and 22-year-old eels serve as premium functional ingredients. The study provides a scientific basis for targeted breeding and market segmentation to enhance the value of eel aquaculture. Full article

Flooding in Tempe Lake, Indonesia, poses ongoing socioeconomic challenges, mainly affecting food security, agricultural output, and household livelihoods. The recurrent and unpredictable floods disrupt planting and harvesting periods, resulting in significant food production deficits and posing complex adaptive challenges for residents. This study examines the socioeconomic adaptation strategies employed by rice farmer households to mitigate the adverse effects of flooding. The study analyzed a random sample of 160 people, utilized descriptive–analytical methodologies, and displayed the findings through graphs and matrix tables. Research reveals that fishing and rice farming serve as the primary revenue sources for households in the region. Despite financial challenges, households maintain security due to dependable food sources and proximity to the lake. The study emphasises the importance of efficient rice cultivation management owing to its short growth cycles and vulnerability to flooding. Moreover, freshwater aquaculture presents a sustainable strategy for mitigating flood risks in climate change, mainly when supported by microcredit, training, and improved market access. The findings highlight the necessity of social and structural adjustments in reducing vulnerability and enhancing community resilience, offering substantial recommendations for improving long-term resilience and food security in flood-prone regions. Full article

To investigate the dietary effects of Astragalus polysaccharides (APSs) on the growth performance, lipid metabolism, antioxidant activity, and non-specific immunity of Asian swamp eel (Monopterus albus) during the domestication stage, fish were randomly allocated into quadruplicate groups receiving Tenebrio molitor-based diets supplemented with Astragalus polysaccharides (APSs) at graded concentrations of 0 (CON), 700 (APS1), 1400 (APS2), and 2100 (APS3) mg/kg body weight for 28 days. The results showed that dietary APSs at 700–1400 mg/kg·bw significantly enhanced the weight gain rate (WG) and decreased the feed conversion ratio (FCR) of M. albus (p < 0.05). Concurrently, hematological analysis revealed that hemoglobin levels increased by 19.9% and 23.0% in the 700 and 1400 mg/kg APS groups, respectively (p < 0.05). In terms of lipid metabolism, supplementation with APSs significantly increased the serum high-density lipoprotein (HDL) content in all treatment groups (p < 0.05). Lower serum triglyceride (TG) levels were found in the APS2 group (p < 0.05), and decreased triglyceride (TG), cholesterol (CHO), and low-density lipoprotein (LDL) levels were displayed in the APS3 group (p < 0.05). Among the antioxidant parameters, the supplementation with 700 mg/kg·bw APSs significantly increased the glutathione peroxidase (GSH-Px) and catalase (CAT) activity levels of M. albus (p < 0.05). The APS2 group had a significantly increased total antioxidant capacity (T-AOC) and CAT activity levels (p < 0.05), and the APS3 group had significantly increased CAT activity levels (p < 0.05). In addition, the APS1 and APS3 groups had significantly reduced malondialdehyde (MDA) levels (p < 0.05). In terms of non-specific immunity, the APS1 and APS2 groups showed significantly increased superoxide dismutase (SOD) and lysozyme (LZM) activity levels of M. albus (p < 0.05), and the addition of 700 mg/kg·bw APSs significantly increased the levels of alkaline phosphatase (AKP) activity (p < 0.05). Furthermore, the levels of acid phosphatase (ACP) activity were significantly increased in all experimental groups (p < 0.05). In conclusion, the optimal APS addition for T. molitor as biocarrier bait is 700 mg/kg, corresponding to 352 mg/kg, which elicits improvements in the growth parameters, lipid homeostasis regulation, oxidative stress mitigation, and innate immune potentiation of M. albus during the domestication stage. Full article

Variations in salinity levels in aquaculture significantly influence fish physiology, impacting population dynamics and industry viability. This study aimed to examine the physiological response of the freshwater drum (Aplodinotus grunniens) to differing salinity conditions, assessing its potential for cultivation in brackish water environments. Fish averaging 45 ± 0.1 g were subjected to acute salinity tests across three groups: a control group at 0‰ and experimental groups at 7.5‰ and 15‰ over four days. The initial findings indicated that A. grunniens could tolerate salinity levels up to 15‰ without adverse effects. Key biochemical markers, such as aspartate aminotransferase and alanine aminotransferase, exhibited significant fluctuations but decreased over time. Antioxidant enzyme activity increased relative to the control, while malondialdehyde levels declined, indicating effective oxidative stress management. Additionally, digestive enzymes like amylase and lipase demonstrated adaptability to changing salinity. The expression of heat shock proteins 70 and 90 in the gills and livers varied initially but showed no sustained changes. Overall, the results suggest that A. grunniens possesses notable resilience to salinity variations, indicating its suitability for brackish water aquaculture and highlighting the optimal salinity ranges for promoting growth. Full article