Search Results (238)

This research investigates the effects of incorporating cyanobacterium Oscillatoria limnetica (OL) powder into aquafeeds on the growth rates, activity of digestive enzymes, antioxidant status, and innate immune responses of white-leg shrimp, Litopenaeus vannamei. The shrimps’ resistance against possible infection with Vibrio harveyi was also examined. For 12 weeks, shrimps (1.26 ± 0.088 g) were nourished on experimental diets with 0.0, 0.75, 1.5, 2.25, and 3.0 g OL/kg feed, represented as OL0, OL0.75, OL1.5, OL2.25, and OL3.0, respectively. At the end of the feeding trial, shrimps were challenged by V. harveyi, and their mortality was further observed for further ten days. The shrimps fed on OL-enriched diets, particularly OL3.0, showed significantly greater growth, digestive enzyme activities, and innate immunity performance than those fed on the control diet (OL0). Compared to the control group, enzymatic antioxidant parameters (CAT and SOD) were significantly (p < 0.05) higher; meanwhile, MDA levels showed marked declines in shrimps fed on OL-containing diets (particularly OL3.0). The relative mRNA expression of antioxidant-related genes (cMn-SOD, CAT, and GPx) and immune-related genes (HMC, Alpha2M, ProPO, and Pen3a) was upregulated in the OL-fed animals compared to the control group. The intestinal morphometry was markedly enhanced in the animals fed on OL-enriched diets, especially with respect to the OL3.0 diet. After the bacterial challenge assay against V. harveyi for ten days, shrimps fed on the control diet had 83.3% mortality; meanwhile, the mortality rate was lower in shrimp groups fed on OL diets, particularly OL3.0 (46.7%). This study demonstrates that L. vannamei benefits from dietary inclusion of O. limnetica (3.0 g/kg feed) through accelerating its growth due to better digestion of diets. Additionally, the OL meal acts as a functional ingredient that fortifies the shrimp against possible V. harveyi infection by enhancing their biological defense system. Full article

This study evaluated locally available dry feed formulations (FFs) as practical alternatives to fresh Chlorella sp. for culturing the freshwater fairy shrimp Streptocephalus sirindhornae. Seven dietary treatments were evaluated, including fresh Chlorella sp. at 1 × 10⁶ cells mL⁻¹ (FF1; control) and six mixed dry diets (FF2–FF7) formulated from spirulina powder, commercial shrimp feed, fish meal, and rice bran. Fairy shrimp were cultured for 20 days in a completely randomized design with three replicates per treatment at a stocking density of 30 individuals L⁻¹. Growth performance (body length and wet body weight) and survival were assessed across three developmental stages (1–5, 6–10, and 11–20 days post-hatch). Across all developmental stages, FF2 (50% spirulina powder + 50% commercial shrimp feed) consistently supported culture performance comparable to that of the control treatment. During the early developmental stage (1–5 days post-hatch), shrimp fed FF2 exhibited growth and survival rates comparable to those of the control group and significantly higher (p < 0.05) than those observed in several other dry diet treatments. During the late developmental stage (11–20 days post-hatch), survival of shrimp fed FF2 (62.45 ± 5.28 percent) did not differ significantly from that of the control group (61.85 ± 4.25 percent) but was significantly higher (p < 0.05) than survival in the other dry diet treatments. In addition, shrimp biomass produced with FF2 showed greater protein, lipid, carotenoid, and amino acid contents than shrimp fed fresh Chlorella sp. Protein, lipid, and amino acid contents were determined using standard AOAC methods, and carotenoid content was analyzed by HPLC. These findings suggest that FF2 may serve as a practical algae-independent diet for maintaining growth and survival of S. sirindhornae under controlled hatchery conditions. Full article

Efficient feed management is essential in aquaculture, especially for bottom-feeding species such as shrimp that require feed delivery at the tank bottom. Most commercial automated feeders are designed for surface-feeding fish and are unsuitable for benthic organisms, leading to feed waste and uneven distribution. This study developed and evaluated an automatic bottom feeder capable of dispensing sinking pellets directly to the substrate. The system integrated a 3D-printed auger for precise feed metering and a closed-type centrifugal impeller positioned at the water surface to achieve radial dispersion of feed. An Arduino Uno microcontroller operated the impeller speed (285.98–586.85 rpm), feed mass (95.23–285.68 g), and dispersion time (2–8 s). A Box–Behnken response surface methodology was used to analyze the influence of these parameters on the mean radius spread of feed, supported by image-based uniformity assessment using OpenCV. Results identified impeller speed as the most significant factor (p = 0.010), with optimal dispersion observed at moderate speeds and longer spread durations. The system demonstrated reliable mechanical performance and precise control, providing a novel, programmable solution for uniform feed delivery in shrimp aquaculture and a promising foundation for scalable, automated bottom-feeding technologies. Full article

Overcoming fishmeal dependence is crucial for the sustainable development of Penaeus vannamei aquaculture, yet the molecular mechanisms underlying the efficient utilization of plant-based diets remain poorly understood. In this study, residual feed intake (RFI) was used as an indicator to investigate these mechanisms. Transcriptome sequencing of the intestine, hepatopancreas, and muscle was performed on shrimp fed a plant-based diet, followed by weighted gene co-expression network analysis (WGCNA) and validation in an independent population. Phenotypic analysis revealed extensive variation in growth performance and RFI among individuals fed the plant-based diet. WGCNA identified four tissue-specific modules significantly associated with RFI, from which 20 hub genes were screened. Independent validation confirmed that seven genes were significantly differentially expressed between high- and low-feed-efficiency groups (q < 0.1): five in the intestine (LOC113811628, LOC113811631, LOC113824170, LOC113817752, LOC113811632) and two in the hepatopancreas (LOC113809216, LOC113820990). These genes are involved in mitochondrial function, energy metabolism, intracellular pH homeostasis, and nucleic acid metabolism, suggesting potential coordination between the intestine and hepatopancreas in response to plant-based diets. Collectively, these findings provide insights into the genetic basis of shrimp adaptation to plant-based diets and offer candidate molecular targets that may inform selective breeding efforts aimed at improving feed efficiency in P. vannamei. Full article

Our previous studies found that lipid emulsifiers can promote the absorption and deposition of liposoluble pigments in shrimp. The present study aimed to further investigate the effects of liposoluble pigments lutein (LUT) and lycopene (LYC), and their combination with lysophospholipids (LPL), on the growth performance, body coloration, and lipid composition of Pacific white shrimp Penaeusvannamei. Five diets were formulated: a control diet (Control), Control + 0.02% lutein (LUT), Control + 0.02% lycopene (LYC), LUT + 0.1% LPL (LUT + LPL), and LYC + 0.1% LPL (LYC + LPL). The feeding trial lasted for 8 weeks. There were no significant differences in shrimp growth and body composition among all groups. Both LUT and LYC increased the redness (a*) and yellowness (b*) of cooked shrimp. LPL synergistically enhanced the pigmentation-improving effects of LUT but weakened those of LYC. Additionally, LYC decreased the redness and yellowness of raw shrimp. Both LUT and LYC reduced the contents of saturated fatty acids and EPA while increasing the DHA content; LPL further enhanced this modulatory effect. In conclusion, LPL acts synergistically with LUT to improve the body coloration and modify the fatty acid composition of Pacific white shrimp, but its effect with LYC is limited. Full article

The present study investigated how dietary inclusion of solubilized mannan oligosaccharide (MOS) influences growth performance, digestive health, stress resilience, and production profitability in Pacific white shrimp (Penaeus vannamei) reared under intensive synbiotic conditions. Juveniles averaging 3.00 ± 0.04 g were stocked at 100 shrimp m⁻² and fed experimental diets containing 0 (control), 1.0, 2.0, or 4.0 g kg⁻¹ MOS for 60 days. Shrimp receiving 1.0 g kg⁻¹ MOS showed higher growth rate, improved feed conversion, and greater final body weight than the control (p < 0.05), indicating enhanced feed utilization efficiency and better overall performance. Gut morphology improved in MOS-fed treatments, with increased mucosal fold height and enterocyte height, suggesting increased nutrient absorption and improved gut functionality. Gut presumptive total count remained relatively stable among treatments, although Bacillus counts tended to increase with solubilized MOS supplementation. Under ammonia and nitrite stress, supplemented groups showed higher survival and reduced gill damage, indicating improved physiological tolerance and health status. Economic analysis demonstrated that 1.0 and 2.0 g kg⁻¹ MOS achieved the best cost–benefit ratios under intensive conditions. Overall, moderate MOS supplementation enhanced growth, gut morphology, stress resistance, and economic efficiency. Polynomial regression analysis, based on the four dietary inclusion levels evaluated, suggested that approximately 1.5 g kg⁻¹ MOS may represent an estimated optimal inclusion level. Full article

This study investigated the replacement of squid-liver powder (SLP) with different marine protein hydrolysates in diets for Pacific white shrimp (Litopenaeus vannamei) over an eight-week feeding period. A control diet contained 5% SLP, whereas four test diets replaced 1% of the diet (dry-matter basis) with tuna hydrolysate liquid (TH), shrimp hydrolysate powder (SH), fish hydrolysate powder (FH), or salmon silage liquid (SS), with soybean meal adjusted to maintain dietary protein balance. Shrimp fed the TH diet showed higher final body weight (15.76 ± 0.24 g shrimp⁻¹) and specific growth rate (3.18 ± 0.02% day⁻¹) than those fed the other experimental diets (p < 0.05). TH also increased feed intake (20.96 ± 0.49 g shrimp⁻¹) and was associated with higher trypsin activity (3236 ± 226 unit h⁻¹ mg protein⁻¹) and improved protein digestibility. Histological observations indicated greater hepatopancreatic cell density and increased intestinal villus height in the TH group. In addition, survival of shrimp fed TH (90.0 ± 2.8%) was higher than that observed in the FH and SS groups (p < 0.05), and hemolymph from TH-fed shrimp showed stronger inhibitory activity against Vibrio parahaemolyticus. Overall, among the evaluated hydrolysates, 1% tuna hydrolysate (dry-matter basis) produced the most consistent improvements across growth performance, digestive capacity, and selected health-related indicators, supporting its feasibility as a partial substitute for squid liver powder in shrimp diets. Full article

Thamnaconus septentrionalis is an economically important marine aquaculture species in China. However, the acceptance rate of formulated feeds in commercial farming is only 30–40%, substantially lower than the 80–90% achieved with fresh feeds, which severely constrains the intensive development of this industry. The gut microbiota-mediated regulatory mechanisms underlying the effects of different feed types on growth performance remain unclear, limiting the precise development of efficient formulated feeds. This study established four feed types (commercial pellet feed K, custom-formulated feed P, frozen shrimp X, and fresh fish meat Y) through a 60-day feeding trial. Growth performance data, 16S rRNA sequencing, and untargeted metabolomics were analyzed. Random Forest-Partial Least Squares Regression models were employed to identify key microbial-metabolite features. Results indicated that the Y group exhibited the optimal feed conversion ratio (1.14), with intestinal Firmicutes abundance (45.3%) significantly higher than the K group (28.5%). Short-chain fatty acid levels increased by more than 350-fold, enriching short-chain fatty acid-producing bacteria such as Lactobacillus and Faecalibacterium. The P group, formulated with high fishmeal content (40%), achieved performance levels comparable to the Y group across most indicators. Machine learning models identified key microbial-metabolite features predicting growth performance, providing a multi-omics framework for developing efficient formulated feeds for marine carnivorous fish. Full article

This study examined the life characteristics, fecundity, and innate immune response of fairy shrimp (Branchinella thailandensis Sanoamuang, Saengphan and Murugan, 2002) cultivated on Chlorella vulgaris, biofloc, dried powder Spirulina sp., and a formulated feed. These feeds were selected to compare traditional live feed (Chlorella vulgaris), microbial-based feed (biofloc), and alternative dry feed in order to identify a sustainable feeding strategy for fairy shrimp culture. The lifespans of male and female fairy shrimp reared on the biofloc diet were the longest at 44 ± 6.00 and 44.33 ± 4.67 days, respectively. Fairy shrimp reared on the biofloc diet demonstrated significantly enhanced growth, with lengths of 25.66 ± 1.75 mm in males and 27.60 ± 2.08 mm in females. The highest fecundity was also observed in the biofloc treatment, with 25 ± 6.65 broods per female, an average of 229.57 ± 2.08 eggs per brood, and a total of 5726.33 ± 1518.11 eggs per female over their lifespan. Fairy shrimp fed with Chlorella vulgaris, biofloc, and Spirulina sp. showed significantly high levels of superoxide dismutase (SOD) and lysozyme activities compared to those fed on a formulated feed, while malondialdehyde (MDA) levels, a marker of oxidative stress, were lower in these three groups. Results suggested that biofloc was a viable feed option for B. thailandensis, which positively influenced growth, lifespan, and fecundity while enhancing the innate immune function. Full article

Understanding the feeding physiological mechanisms of determined oyster species is fundamental for adaptation and growth stabilization, aiming for gains in aquaculture production. To assess its potential for Integrated Multi-Trophic Aquaculture (IMTA) with shrimp, we analyzed the feeding physiology of the mangrove oyster Crassostrea gasar. In this study, we determined the feeding physiology of the mangrove oyster Crassostrea gasar, a commercially important species in tropical Brazil, under two diets, live microalgae (ISO—Isochrysis galbana) and biofloc (BFT), which were tested at four concentrations (10, 20, 30, and 40 mg L⁻¹), to establish whether this species can effectively utilize BFT as a food source. Results indicated that ISO diet promoted superior filtration, characterized by a higher proportion of feces (F), suggesting a reduced need for intensive particle selection. Both clearance (CR) and filtration (FR) rates peaked at 30 mg L⁻¹ before declining, suggesting a physiological threshold for this diet. In contrast, the BFT diet elicited higher CR and FR values but triggered excessive pseudofeces (PF) production and low net organic selection efficiency (NOSE). This suggests high particle rejection and limited nutritional assimilation. In conclusion, while C. gasar can process BFT, it is metabolically disadvantageous as a sole food source. For an optimal performance, I. galbana concentrations should be maintained at or below 30 mg L⁻¹. Full article

Intensive aquaculture induces severe environmental stress and disease susceptibility in Pacific white shrimp (Litopenaeus vannamei). Cannabidiol (CBD) offers significant potential as a bioactive stress-mitigating additive. This study evaluated the effects of dietary CBD supplementation (0, 10, 20, 40, and 80 mg/kg) on the growth, intestinal microecology, and stress tolerance of juvenile L. vannamei over an 8-week feeding trial, followed by a combined chronic ammonia and acute hypoxia challenge. Moderate CBD supplementation (10–40 mg/kg) significantly promoted growth, minimized feed conversion ratios, and enriched muscle eicosapentaenoic (EPA) and docosahexaenoic acids (DHA). Furthermore, CBD restructured the intestinal microbiota by suppressing opportunistic pathogens and enriching beneficial taxa. Under combined stress, moderate CBD prolonged the median lethal time (LT₅₀) by up-regulating hypoxia-inducible factor 1-alpha (hif-1α) and heat shock protein 70 (hsp70) transcription and boosting systemic antioxidant capacity to neutralize lipid peroxidation. Conversely, the highest dose (80 mg/kg) induced metabolic exhaustion and hepatopancreatic toxicity, evidenced by drastically elevated serum transaminases and diminished stress tolerance. Conclusively, dietary CBD exerts a classic biphasic effect in L. vannamei. Inclusion at 10–40 mg/kg safely promotes the best comprehensive effects on growth, immune homeostasis, and environmental resilience within the concentration range tested in this study, whereas excessive administration provokes severe metabolic burden, highlighting the critical need for strict dosage regulation. Full article

This study investigated the effects of dietary Bacillus cereus, administered alone or in combination with biofloc technology, on the growth performance, immune response, disease resistance, and intestinal microbiota of Litopenaeus vannamei. Shrimp fed diets supplemented with B. cereus, either directly or via biofloc systems, exhibited significantly increased final body weight and specific growth rate, together with a reduced feed conversion ratio compared with the control group. The expression levels of key hepatopancreatic immune-related genes, including lysozyme, prophenoloxidase, superoxide dismutase, Toll, immune deficiency, and Relish, were significantly upregulated in probiotic-associated treatments. Following challenge with Vibrio parahaemolyticus, cumulative mortality was markedly lower in all treatments involving B. cereus or biofloc compared with the control. Although alpha diversity indices were not significantly affected, beta diversity analysis demonstrated that supplementation frequency and delivery mode altered intestinal microbial community structure. The phyla Bacteroidota, Firmicutes, and Proteobacteria predominated across treatments, while members of Marinilabiliaceae and Shewanellaceae were enriched under probiotic-associated conditions, suggesting enhanced nutrient transformation potential. Co-occurrence network analysis further revealed increased microbial network complexity and positive interactions in probiotic and biofloc treatments, indicating improved community stability. These findings demonstrate that the synergistic application of B. cereus and biofloc technology enhances growth performance, immune capacity, and intestinal microbial resilience in intensive shrimp culture, and that supplementation strategy plays a critical role in optimizing probiotic efficacy. Full article

Pacific white shrimp (Litopenaeus vannamei) is a major aquaculture product worldwide. For consumers, discriminating domestic from imported sources of shrimp meat, and individual domestic sources, can be highly desirable because of the different meat quality and environmental contamination from geographically different origins of shrimp. This study evaluated the potential of stable isotope analysis (δ¹³C, δ¹⁵N, δ²H, δ¹⁸O) with chemometric models to authenticate the origins of Pacific white shrimp sold in China. Shrimp samples from domestic (Guangxi, Fujian, Shandong, Inner Mongolia) and foreign (Ecuador) sources were analyzed, using statistical analyses. The four-isotope model achieved 89.3% cross-validation accuracy in distinguishing domestic and foreign shrimp, with an overall prediction Area Under the Curve (AUC) of 0.901 (95% CI: 0.819–0.983)—significantly outperforming single-isotope models. Differences in δ¹³C and δ¹⁵N reflected feed source variations, while δ²H and δ¹⁸O (Variable Importance in the Projection (VIP) > 1, key discriminatory indicators) mirrored geographic environmental difference. Although δ¹⁵N did not differ significantly among groups, the combination of all four isotopes reduced limitations of individual δ²H/δ¹⁸O use. This approach enhanced the precision, reliability, and applicability of stable isotope analysis for origin authentication by leveraging complementary isotopic data and robust statistical frameworks. These findings demonstrate the proposed model’s potential as a cost-effective, copyright-compliant framework for shrimp origin authentication, with implications for isotopic traceability across food science fields. Full article

Background/Objectives: Low-fishmeal diets are widely adopted to improve sustainability in shrimp aquaculture, yet reduced palatability and metabolic stress frequently suppress feed intake and growth. We evaluated whether a crayfish (Procambarus clarkii) by-product protein hydrolysate (CBPH) could mitigate low-fishmeal-induced performance losses by modulating feeding-related metabolic signaling and gut microbiota features in Pacific white shrimp (Litopenaeus vannamei). Methods: In an 8-week feeding trial, 360 juveniles (initial body weight 0.46 g) were assigned to three diets (four replicates per diet): a commercial control (CON), a low-fishmeal diet (LFM), and LFM supplemented with 2% CBPH (CBPH). Growth, feed utilization, whole-body composition, hemolymph biochemical indices (TP, TG, GLU, AST, ALT), intestinal appetite-related gene expression (5-HTR, CART, CCK1R, D2-like, NPY), and intestinal microbiota profiles (full-length 16S rRNA sequencing, V1–V9, PacBio) were assessed. Results: Compared with the LFM group, CBPH supplementation increased feed intake and improved feed conversion, restoring final body weight and growth rates to levels comparable to CON. CBPH also alleviated low-fishmeal-associated metabolic stress, including reduced AST and ALT activities and lower glucose levels. The LFM diet induced upregulation of anorexigenic genes (5-HTR, CART, D2-like) and downregulation of NPY in the shrimp intestine, whereas CBPH supplementation reversed these transcriptional changes. In addition, microbiota richness indices (ACE and Chao1) were elevated by CBPH relative to LFM, accompanied by compositional shifts at the phylum and genus levels. Conclusions: CBPH effectively alleviated low-fishmeal-induced reductions in feeding and growth, accompanied by coordinated changes in feeding-related gene expression, systemic biochemical markers, and gut microbiota composition, supporting its potential as a functional ingredient to stabilize metabolic responses in low-fishmeal shrimp feeds. Full article

This 90-day trial evaluated the integrated benefits of biofloc technology (BFT) in lined ponds for intensive Penaeus vannamei culture, comparing it with a conventional water-exchange (WE) system. The BFT system maintained favorable water quality with a 68.4% reduction in cumulative water exchange. Concentrations of toxic total ammonia–nitrogen (TAN) and nitrite–nitrogen (NO₂⁻-N) were better controlled, and total suspended solids (TSS) stabilized within a beneficial range (150–200 mg L⁻¹). Microbial analysis indicated that BFT significantly increased total bacterial abundance in both culture water and shrimp hepatopancreas while reducing the total Vibrio-to-bacteria ratio in culture water to below 6%, significantly lower than in the WE system (>18%). Moreover, BFT significantly lowered the loads of specific pathogens, acute hepatopancreatic necrosis disease (AHPND)-causing Vibrio parahaemolyticus, and Enterocytozoon hepatopenaei (EHP) in both culture water and shrimp hepatopancreas. Regarding production performance, BFT significantly enhanced shrimp survival rate (82.4% vs. 71.5%), yield (3460 vs. 2948 kg pond⁻¹), and water productivity (0.85 vs. 0.28 kg m⁻³), while lowering the feed conversion ratio (1.16 vs. 1.33). In conclusion, BFT achieves stable water quality, effective pathogen suppression, and enhanced production efficiency through microbial regulation, offering a viable water-saving, environmentally sound, and disease-resilient strategy for intensive P. vannamei culture. Full article