Litopenaeus Vannamei Research Articles

Dietary Supplementation with Hydrolyzable Tannin Improves Nonspecific Immune Responses, Intestinal Morphology, and Disease Resistance against Vibrio alginolyticus in Whiteleg Shrimp

This research aimed to evaluate the impact of hydrolyzable tannin on immune responses, intestinal morphology, and resistance to Vibrio alginolyticus in whiteleg shrimp (Penaeus vannamei). In preliminary in vitro experiments, shrimp hemocytes were exposed to different concentrations of hydrolyzable tannin. The findings indicated that hydrolyzable tannin exhibited nontoxic characteristics and could stimulate respiratory burst activity. For the subsequent in vivo trial, shrimp (11.83 ± 0.98 g) were subjected to a 28-day oral administration of diets containing diverse hydrolyzable tannin concentrations (0, 1, 2, 4, and 8 g/kg denoted as control, T1, T2, T4, and T8, respectively). Immune parameters, antimicrobial peptide genes, and intestinal morphology were measured. Significant enhancements were observed in total hemocyte count (THC), phagocytic activity, respiratory burst activity, and phenoloxidase activity (PO) across all treatment groups compared to the control group, particularly in T2 and T4 groups (p<0.05). The gene expressions of Penaeidin-2, Penaeidin-3, Penaeidin-4, crustin, and lysozyme were markedly higher in the treatment groups, especially in T2 (p<0.05). Additionally, hydrolyzable tannin contributed to increased intestinal wall thickness after the 28-day feeding trial (p <0.05). In a separate challenge experiment, shrimps (11.36 ± 0.66 g) were exposed to V. alginolyticus after 7 days of culture. Notably, T2 and T4 exhibited enhanced resistance, resulting in survival rates of 66.67% and 69.70%, respectively. To conclude, administering 4 g of hydrolyzable tannin per kilogram of feed proved effective in enhancing nonspecific immune responses, improving intestinal morphology, and augmenting resistance to V. alginolyticus in whiteleg shrimp.

Yarrowia lipolytica as a promising protein source for Pacific white shrimp (Litopenaeus vannamei) diet: impact on growth performance, metabolism, antioxidant capacity, and apparent digestibility

Exploring alternatives to fishmeal (FM) in aquaculture nutrition remains a hot topic in this area. Yarrowia lipolytica (YL), a promising single-cell protein source, has yet to be evaluated for its use on the Pacific white shrimp (Litopenaeus vannamei) diet. This investigation assessed the effects of YL on growth performance, metabolism, antioxidant capacity, and nutrient digestibility in shrimp. Seven diets with equal protein and lipid contents were prepared, incorporating gradient YL (dry matter basis): 0% (control), 1.50%, 3.00%, 4.50%, 6.00%, 9.00%, and 12.00%. During a 56-day feeding trial involving shrimp, with an initial average weight of 0.32 ± 0.02 g, each kind of diet was randomly assigned to six tanks. It was observed that the growth performance improved initially but then exhibited a declining trend as the dietary inclusion of YL increased. Regression analysis indicated 2.68% as the optimal YL percentage for a specific growth rate (SGR), accounting for 10.54% of the dietary FM content. A higher YL (over 6.00%), which is equivalent to replacing over 23.6% of the FM, led to increased feed intake and conversion ratios, possibly correlating with decreased YL digestibility. However, YL inclusion across the studied range had no detrimental impact on intestinal or hepatopancreatic morphology. Notably, higher YL levels significantly enhanced hepatopancreatic trypsin activity and reduced serum triglyceride and cholesterol levels. The inclusion of YL notably augmented antioxidant defense mechanisms in shrimp, as evidenced by increased total antioxidant capacity and catalase activities, as well as reduced malondialdehyde levels in the hepatopancreas, possibly due to the presence of β-glucan and mannan oligosaccharides in YL. These findings support YL being viable as a protein source in shrimp feeds.

A Distributed Deep Learning Network Based on Data Enhancement for Few-Shot Raman Spectral Classification of Litopenaeus vannamei Pathogens

Litopenaeus vannamei is a common species in aquaculture and has a high economic value. However, Litopenaeus vannamei are often invaded by pathogenic bacteria and die during the breeding process, so it is of great significance to study the identification of shrimp pathogenic bacteria. The wide application of Raman spectroscopy in identifying directions of inquiry provides a new means for this. However, the traditional Raman spectroscopy classification task requires a large amount of data to ensure the accuracy of its classification. Therefore, the question of how to obtain higher classification accuracy through the means of a small amount of Raman spectrum data is a difficult point in the research. This paper proposes a distributed deep learning network based on data enhancement for few-shot Raman spectral classification of Litopenaeus vannamei pathogens. The network consists of RSEM, RSDM, and DLCM modules. The RSEM module uses an improved generative adversarial network combined with transfer learning to generate a large amount of spectral data. The RSDM module uses improved U-NET to denoise the generated data. In addition, we designed a distributed learning classification model (DLCM) which significantly speeds up model training, improves the efficiency of the algorithm, and solves the network degradation problem that often occurs during deep learning model training. The average classification accuracy of our proposed network on four shrimp pathogenic bacteria reaches 98.9%, which is higher than several models commonly used in Raman spectroscopy classification tasks. The method proposed in this article only needs the Raman spectra of a small number of microorganisms to complete the efficient and rapid identification of shrimp pathogenic bacteria, and this method certainly has the potential to solve the problem of the spectral classification of other microorganisms.

Synergistic effects of combined probiotics Bacillus pumilis D5 and Leuconostoc mesenteroide B4 on immune enhancement and disease resistance in Litopenaeus vannamei

This study investigated the effects of two distinct probiotics, Leuconostoc mesenteroides B4 (B4) and Bacillus pumilus D5 (D5), along with their combination, on the diet of white shrimp (Litopenaeus vannamei) during an eight-week feeding trial. The diets tested included B4 + dextran at 107 CFU/g feed (the B4 group), D5 alone at 107 CFU/g feed (the D5 group), and a combination of B4 + dextran and D5 at 5 × 106 CFU/g feed each (the B4+dextran + D5 group). Relative to the control group, those administered probiotics exhibited moderate enhancements in growth. By the eighth week, the weight gain for the B4, D5, and B4+D5 groups was 696.50 ± 78.15%, 718.53 ± 130.73%, and 693.05 ± 93.79%, respectively, outperforming the control group's 691.66 ± 31.10% gain. The feed conversion ratio was most efficient in the B4 group (2.16 ± 0.06), closely followed by B4+D5 (2.21 ± 0.03) and D5 (2.22 ± 0.06), with the control group having the highest ratio (2.27 ± 0.03). While phenoloxidase activity was somewhat elevated in the B4 and D5 groups, no significant differences were noted in respiratory burst activity or total hemocyte count across all groups. Challenge tests at weeks 4 and 8 showed that the B4 + D5 combination offered superior protection against AHPND-causing Vibrio parahaemolyticus. The 4-week cumulative survival rate was highest in shrimp treated with B4 + dextran + D5 (56.25%), followed by B4 + dextran (31.25%), control (18.75%), and lowest in D5 (12.5%). By week 8, the B4 + dextran + D5 (43.75%) and B4 + dextran (37.5%) groups significantly outperformed the control group (6.25%, p < 0.05), with no significant difference observed between the D5 group (37.5%) and the control group at day 56. Analysis of the shrimp's foregut microbiota revealed an increase in unique OTUs in the B4 and B4 + D5 groups. Compared to the control, Proteobacteria abundance was reduced in all probiotic groups. Potential pathogens like Vibrio, Bacteroides, Neisseria, Botrytis, Clostridioides, and Deltaentomopoxvirus were detected in the control but were reduced or absent in probiotic groups. Beneficial microbes such as Methanobrevibacter and Dictyostelium in the B4+D5 group, and Sugiyamaella in the B4 group, showed significant increases.Probiotics also led to higher transcript levels of nitric oxide synthase in the hemocytes, and lysozyme and transglutaminase in the midgut, along with lysozyme and α2-macroglobulin in the foregut. Notably, the combined B4 + D5 probiotics synergistically enhanced the expression of superoxide dismutase and prophenoloxidase in the foregut, indicating an improved immune response. In summary, this study demonstrates that the probiotics evaluated, especially when used in combination, significantly boost the expression of specific immune-related genes, enhance the bacterial diversity and richness of the intestine, and thus prevent the colonization and proliferation of Vibrio spp. in L. vannamei.

Toll-like receptor expression in Pacific white shrimp (Litopenaeus vannamei) reveals differential responses after fungal (Fusarium solani) infection

Toll-like receptor expression in Pacific white shrimp (Litopenaeus vannamei) reveals differential responses after fungal (Fusarium solani) infection

Shelf-life extension of Pacific white shrimp (Litopenaeus vannamei) using sodium alginate/chitosan incorporated with cell-free supernatant of Streptococcus thermophilus FUA 329 during cold storage.

Seafood is highly perishable and has a short shelf-life. This study investigated the effect of chitosan and alginate (CH-SA) coating combined with the cell-free supernatant of Streptococcus thermophilus FUA329 (CFS) as a preservative on the quailty of white shrimp (Litopenaeus vannamei) refrigerated at 4° for 0, 3, 6, 9, 12, 15 days. Freshly shrimps were randomly divided into four groups: the CFS group (400 mL); the CH-SA group (1% chitosan/1% alginate); the CFS-CH-SA group (1% chitosan/1% alginate with 400 mL CFS) are treatment groups, and the control group (400 mL sterile water). The CFS-CH-SA coating effectively suppressed microbial growth total viable count and chemical accumulation (pH, total volatile basic nitrogen, thiobarbituric acid reactive substance) compared with the control. Additionally, the CFS-CH-SA coating improved the texture and sensory characteristics of shrimp during storage. The coated shrimp exhibited significantly reduced water loss (p<0.05). The combination of CH-SA coating with CFS treatment can extend the shelf life of shrimp. PRACTICAL APPLICATION: Recently, edible films have received more consideration as a promising method to enhance the shelf life of seafood. The presence of Lactic acid bacteria metabolites in edible films reduces spoilage and improves consumer health. Our findings encourage the application of edible coating incorporated with cell-free supernatant of Streptococcus thermophilus FUA 329 to design multifubctional foods and preserve the qualities of shrimp.

Improved genome assembly of the whiteleg shrimp Penaeus (Litopenaeus) vannamei using long- and short-read sequences from public databases.

The Pacific whiteleg shrimp Penaeus (Litopenaeus) vannamei is a highly relevant species for the world's aquaculture development, for which an incomplete genome is available in public databases. In this work, PacBio long-reads from 14 publicly available genomic libraries (131.2 Gb) were mined to improve the reference genome assembly. The libraries were assembled, polished using Illumina short-reads, and scaffolded with P. vannamei, Feneropenaeus chinensis, and Penaeus monodon genomes. The reference-guided assembly, organized into 44 pseudo-chromosomes and 15,682 scaffolds, showed an improvement from previous reference genomes with a genome size of 2.055 Gb, N50 of 40.14 Mb, L50 of 21, and the longest scaffold of 65.79 Mb. Most orthologous genes (92.6%) of the Arthropoda_odb10 database were detected as "complete," and BRAKER predicted 21,816 gene models; from these, we detected 1,814 single-copy orthologues conserved across the genomic references for Marsupenaeus japonicus, F. chinensis, and P. monodon. Transcriptomic-assembly data aligned in more than 99% to the new reference-guided assembly. The collinearity analysis of the assembled pseudo-chromosomes against the P. vannamei and P. monodon reference genomes showed high conservation in different sets of pseudo-chromosomes. In addition, more than 21,000 publicly available genetic marker sequences were mapped to single-site positions. This new assembly represents a step forward to previously reported P. vannamei assemblies. It will be helpful as a reference genome for future studies on the evolutionary history of the species, the genetic architecture of physiological and sex-determination traits, and the analysis of the changes in genetic diversity and composition of cultivated stocks.

Strengthening of VANNAME (Litopenaeus vannamei) seeds that are preserved in cement seeds through the application of FITOIMUN®

The purpose of this study was to evaluate the addition of FITOIMUN® made of acid shrimp extract (Solanum ferox) and key interviews (Boesenbergia pandurata) on survival, absolute weight growth, daily growth rate, feed conversion rate, and water quality parameters of the vandame shrimpsined in cement tanks. This study uses a complete random design (RAL) with 3 treatments and 3 repetitions. The doses of FITOIMUN® used in the treatment are 0 mL/kg (P0), 20 mL/kg (P1), and 24 mL (P2). The shell used is 20±0,5 g and is kept in a cement tank of 4.5 x 5.5 x 95 m2. The shrimp are treated with a feeding rate method with a frequency of four times a day. The results of the study show survival at P0, P1, and P2 doses of 100%. Absolute weight growth at P0 (7.41 g), P1 (7.69 g), and P2 (6.85 g). The daily growth rate is P0 (26.47%), P1 (27.48%), and P2 (24.46%), while feed conversion rates are P0 (1,16), P1, (1,14), and P2, respectively. (1,18). The water quality in this study averaged 26.92°C, pH 7.39, DO 6.33 ppm, and salinity 19.55 ppt. In conclusion, the survival rate with the administration of FITOIMUN® to shrimps in all treatments reached 100%; the application of Fitoimun® did not affect absolute weight growth, daily growth rate, or feed conversion rate but had the best value at P1 (20 mL/kg feed); and the water quality parameters in all treatments were still at the appropriate criteria for the life of the vaname shrimp.

Bactericidal efficacy of plasma-activated water against Vibrio parahaemolyticus on Litopenaeus vannamei.

In this study, the antimicrobial mechanism of plasma-activated water (PAW) against Vibrio parahaemolyticus and the effectiveness of PAW in artificially contaminated Litopenaeus vannamei were investigated. The results demonstrated a significant reduction (p < 0.05) in viable counts of V. parahaemolyticus with increasing plasma discharge time (5, 10, 20, and 30 min) and PAW immersion time (3, 5, 10, 20, and 30 s). Specifically, the count of V. parahaemolyticus decreased by 2.1, 2.7, 3.3, and 4.4 log CFU/mL after exposed to PAW 5, PAW 10, PAW 20, and PAW 30 for 30 s, respectively. Significant cell surface wrinkling, accompanied by notable nucleic acid and protein leakage were observed after treatment with PAW. The permeability of the inner and outer cell membranes was significantly increased (p < 0.05), along with an increase in electrical conductivity (p < 0.05). The reactive oxygen species (ROS) within V. parahaemolyticus cells were significantly increased (p < 0.05), while superoxide dismutase (SOD) activity, and the relative expression of the ompW, emrD, and luxS genes were significantly decreased (p < 0.05). A reduction number of 1.3, 1.8, 2.1, and 2.2 log CFU/g of V. parahaemolyticus in artificially contaminated L. vannamei was obtained with PAW for 5 min. The study elucidated that PAW could destroy cell membranes, leading to cell death. The findings would strengthen strategies for V. parahaemolyticus control and provide a potential application of PAW for preserving aquatic products.

Effect of dietary phytase and protease supplementation on the growth performance and apparent nutrient digestibility in juvenile Pacific white shrimp (Litopenaeus vannamei) fed fish meal–free and phosphorus limiting diets

Effect of dietary phytase and protease supplementation on the growth performance and apparent nutrient digestibility in juvenile Pacific white shrimp (Litopenaeus vannamei) fed fish meal–free and phosphorus limiting diets

The Preservation Behavior and Modification Effect of Roselle Anthocyanin–Based Film on Penaeus Vannamei: Biochemical Property Evaluation and Flavor Composition Characterization

The Preservation Behavior and Modification Effect of Roselle Anthocyanin–Based Film on Penaeus Vannamei: Biochemical Property Evaluation and Flavor Composition Characterization

LKB1 regulates autophagy through AMPK/TOR signaling pathway to alleviate the damage caused by Vibrio alginolyticus infection

LKB1 (liver kinase B1) is a key upstream kinase of AMPK and plays an important role in various cellular activities. While the function and mechanism of LKB1 have been widely reported in the study of tumor, there are few reports on its role in bacterial infectious diseases, especially in shrimp. In the present study, molecular characterization revealed that LvLKB1 has an open reading frame (ORF) of 1266 bp encoding 421 amino acids with a molecular weight of about 48 KDa, including the kinase region, N-terminal regulatory domain and C-terminal regulatory domain. LvLKB1 in hepatopancreas and hemocytes was significantly upregulated after infection with Vibrio alginolyticus (V. alginolyticus). After silencing LvLKB1 gene in Litopenaeus vannamei (L. vannamei) and artificially infecting V. alginolyticus, the survival rate of L. vannamei was significantly decreased. Subsequently, it was found that the expression of inflammatory factors in hepatopancreas and hemocytes of shrimp was up-regulated, and the expression of lipid oxidation factors was decreased after silencing LKB1, leading to the phenomenon of lipid accumulation in hepatopancreas. In order to explore the mechanism, autophagy levels of shrimp were detected after silencing LKB1, which showed that autophagy levels in hepatopancreas and hemocytes were significantly reduced. Further studies conclusively showed that silencing LvLKB1 inhibited AMPK phosphorylation induced by V. alginolyticus infection, thereby activating TOR pathway and inhibiting autophagy in shrimp. These results indicate that LvLKB1 regulates autophagy through AMPK/TOR signaling pathway to alleviate the damage caused by V. alginolyticus infection.

Acute stress response in gill of Pacific white shrimp Litopenaeus vannamei to high alkalinity

As a multifunctional organ, the gill plays a key role in the regulation of homeostasis. Excessive alkalinity in water can seriously threaten the survival of aquatic animals, however, the studies on the mechanism of alkalinity stress and adaption of crustacea are still limited. In this study, we aimed to investigate the mechanisms of acute alkalinity stress in the gill of Pacific white shrimp Litopenaeus vannamei by integrating physiological, histological, transcriptome, and metabolome analyses, which is an important aquaculture species of crustaceans. The physiological parameters related to homeostasis regulation, oxidative stress, material metabolism, and ammonia detoxification were significantly changed under acute alkalinity stress. There were a considerable number of genes and metabolites that were significantly changed in expression and level, which related to glycolysis/gluconeogenesis, fatty acid metabolism, amino acid metabolism, antioxidation, ammonia metabolism, and glycerophospholipid metabolism, In addition, the local structure of the gill was damaged and accompanied by cell apoptosis. The above results indicate that acute alkalinity stress can lead to damage to the gill structure, and affect its ion transport function, and the genes related to ion transport protein were upregulated. The antioxidant capacity in the gill was strengthened under acute alkalinity stress, at the same time, acute alkalinity stress would induce apoptosis in the gill. The glycogen catabolism in gill was significantly enhanced under acute alkalinity stress, while the lipid anabolism was inhibited, and the mechanism of the ornithine-urea cycle has been further mobilized to alleviate the inhibition of ammonia excretion and the accumulation of metabolic ammonia in the internal environment. In addition, the glycerophospholipid metabolism in the gill was disturbed under acute alkalinity stress. The current study will provide important clues for understanding the alkalinity stress mechanism of crustaceans, and provide an important theoretical basis for the optimization of shrimp aquaculture in saline-alkaline waters.

Optimal open nucleus breeding system for long-term genetic gain in the Pacific white shrimp using genomic selection

The open nucleus breeding system (ONBS) has been widely employed in livestock breeding and has demonstrated a desirable genetic gain compared to the traditional closed nucleus breeding system (CNBS). However, no related study and application for ONBS exist on aquatic animal breeding. The present investigation simulates the family-based ONBS with different proportions of introduced multiplier individuals used as parents of the nucleus population (NP) and CNBS schemes for the harvest body weight of the Pacific white shrimp (Litopenaeus vannamei). The multiplier population (MP) comprised progenies from eight families with high estimated breeding value (EBV) or genomic EBV (GEBV) of NP of the previous generation. ONBS was assigned three proportions (10%, 30%, and 50%) of the introduced MP individuals. The short-term selection (G0 to G10) and long-term selection (G0 to G20) were performed for CNBS and ONBS schemes using pedigree-based best linear unbiased prediction (PBLUP) with the A relationship matrix from the pedigree or single-step genomic BLUP (ssGBLUP) with the H relationship matrix integrating SNP markers and pedigree. The genetic gain of body weight and inbreeding coefficient of NP for eight breeding schemes with CNBS_PBLUP (CP), CNBS_ssGLUP (CS), ONBS_PBLUP (OP10, OP30, OP50), and ONBS_ssGBLUP (OS10, OS30, OS50) with three proportions of the introduced MP individuals were calculated. Compared to CP, genetic gains for the three OP schemes increased by 7.68 to 11.27% after short-term selection, and by 2.51 to 5.79% after long-term selection. In comparison to CS, genetic gains for the three OS schemes increased by 8.21 to 8.96% after short-term selection, and from 4.46 to 5.87% after long-term selection. The ONBS schemes achieved higher genetic gains than the corresponding CNBS schemes whether using genomic or pedigree information. The advantage of ONBS over CNBS is reduced after long-term selection. Genetic gains for the three OS schemes increased by 9.77 to 14.06% after long-term selection compared with the corresponding OP schemes. Furthermore, no significant difference (P > 0.05) in genetic gain was revealed among the ONBS schemes after either pedigree-based or genomic selection. Inbreeding coefficients for the three OP schemes increased from 59.45 to 70.98% compared with CP, whereas inbreeding coefficients for the three OS schemes increased from 24.72 to 32.22% compared with CS. Besides, after long-term selection, inbreeding coefficients for the three OS schemes decreased from 13.13 to 14.79% compared with the corresponding OP schemes. In a nutshell, ONBS using introduced MP individuals has great promise in the selective breeding program of L. vannamei. Genomic information has more potential to improve selection response and control inbreeding level than pedigree information when applying ONBS.

Salt type, sugar addition, and system type in intensive RAS for Pacific white shrimp (Litopenaeus vannamei) production

The use of a low-cost, homemade salt mixture in hybrid RAS may reduce operational costs for inland marine aquaculture producers. The addition of sugar in RAS may benefit shrimp growth by making suspended microbes richer in protein, which shrimp can then consume. Increased digestive enzyme activity has been noted in shrimp raised in systems with a substantial abundance of biofloc particles. However, there is still debate over whether clear-water RAS may be superior to particulate-rich systems. This study examined the effects of system type, low-cost salt, and sugar addition on the production, water quality, and digestive enzyme activity of L. vannamei. In the study, two levels of each experimental factor were used. The factors used were system type (clear water-CW vs hybrid-HY), salt type (Least Cost-L vs Commercial-C), and sugar (presence or absence of sugar addition: S vs. N). There was a total of eight treatments: HY-L-S, HY-L-N, HY-C-S, HY-C-N, CW-L-S, CW-L-N, CW-C-S, and CW-C-N, each of which had three randomly assigned, replicate, 1 m3 tanks. All tanks were stocked with 250 shrimp per m3 (3.1 g average weight), extra filtration was used in CW tanks, and sugar (sucrose) was added at a targeted C:N ratio of 14:1 in the sugar tanks. At the end of the experiment, the hepatopancreas was removed from shrimp for digestive enzyme analyses. Results from the experiment showed no significant differences in the average weight, total harvest, FCR, and growth rate between system types and salt types. However, the use of sugar resulted in significantly reduced mean individual weight of shrimp. Nitrate concentration was significantly lower and solids concentrations were higher in the tanks receiving sugar compared to those with no sugar addition. There were no significant differences in amylase activity between treatments, but trypsin activity was higher in the HY systems than the CW systems. The results of this study indicate that this particular low-cost salt mixture had no adverse effects on the water quality, production, or enzyme metrics tested. Biofloc particles seem to have enhanced trypsin activity in the HY system shrimp. Lastly, the addition of sugar had some substantial impacts on solids and nitrate concentrations, as well as negative effects on shrimp growth. Both independently and in combination, the factors examined in this project may have important implications for the management of intensive shrimp aquaculture operations.

Dinotefuran exposure alters biochemical, metabolomic, gut microbiome, and growth responses in decapoda pacific white shrimp Penaeus vannamei

Dinotefuran, a neonicotinoid insecticide, may impact nontarget organisms such as Decapoda P. vannamei shrimp with nervous systems similar to insects. Exposing shrimp to low dinotefuran concentrations (6, 60, and 600 μg/L) for 21 days affected growth, hepatosomatic index, and survival. Biomarkers erythromycin-N-demethylase, alanine aminotransferase, and catalase increased in all exposed groups, while glutathione S-transferase is the opposite; aminopyrin-N-demethylase, malondialdehyde, and aspartate aminotransferase increased at 60 and 600 μg/L. Concentration-dependent effects on gut microbiota altered the abundance of bacterial groups, increased potentially pathogenic and oxidative stress-resistant phenotypes, and decreased biofilm formation. Gram-positive/negative microbiota changed significantly. Metabolite differences between the exposed and control groups were identified using mass spectrometry and KEGG pathway enrichment. N-acetylcystathionine showed potential as a reliable dinotefuran metabolic marker. Weighted correlation network analysis (WGCNA) results indicated high connectivity of cruecdysone in the metabolite network and significant enrichment at 600 μg/L dinotefuran. The WGCNA results revealed a highly significant negative correlation between two key metabolites, caldine and indican, and the gut microbiota within co-expression modules. Overall, the risk of dinotefuran exposure to non-target organisms in aquatic environments still requires further attention.

Effects of hydroxyproline supplementation in low fish meal diets on collagen synthesis, myofiber development and muscular texture of juvenile Pacific white shrimp (Litopenaeus vannamei)

This experiment aimed to evaluate the impact of dietary hydroxyproline (Hyp) supplementation on the flesh quality of juvenile Pacific white shrimp (Litopenaeus vannamei) fed a low fishmeal diet. Six formulated diets included one high fishmeal (HF; 25% fishmeal content) and five low fishmeal diets (10% fishmeal content) with 0%, 0.2%, 0.4%, 0.6% and 0.8% Hyp (LF0, LF2, LF4, LF6 and LF8, respectively). Each diet was assigned to four replicates and 40 shrimp (0.32 ± 0.00 g) per replicate were fed four times a day for 8 weeks. Dietary Hyp supplementation had little effects on growth performance, but significantly increased the contents of Hyp, prolyl 4-hydroxylases (P4Hs), and collagen (P < 0.05). The meat yield, springiness, hardness, chewiness, and cohesiveness of muscle were the highest in the LF2 group. Cooking loss and freezing loss of muscle were the lowest in the LF2 group (P < 0.05). Dietary supplementation with 0.4% Hyp increased the myofiber density and decreased the myofiber diameter of muscle (P < 0.05). Supplementation of Hyp in the diet up-regulated the mRNA expression of smyhc5, smyhc15, col1a1, col1a2, igf-1f, tgf-β and tor, and down-regulated the mRNA expression of smyhc 1, smyhc 2, smyhc 6a (P < 0.05). Supplementation of Hyp in the diet up-regulated the protein expression of P-4E-BP1, P-AKT, AKT and P-AKT/AKT (P < 0.05). These results suggested that the addition of 0.4% Hyp to low fishmeal diets improved the flesh quality of L. vannamei.

In vitro and in vivo evaluation of the efficacies of commercial probiotics and disinfectant against acute hepatopancreatic necrosis disease and luminescent vibriosis in Litopenaeus vannamei

The bioactivities of two commercially available probiotics and one chemical disinfectant were tested against strains of Vibrio parahaemolyticus (VPAHPND) and V. harveyi. This study aimed to determine shrimp pathogenic Vibrios' in vitro and in vivo sensitivities to commercial probiotics and a chemical disinfectant. The probiotics and disinfectant were tested first in vitro, followed by the in vivo trials. Results showed that upon administration of probiotics either through diet or adding into the tank water, the survivability of shrimp was increased during challenge with VPAHPND and V. harveyi. Also, the disinfectant was tested against the same pathogens and showed positive bactericidal effects at 2500 ppm and 5000 ppm. The present findings suggest that adding probiotics to the rearing water or the shrimp feeds effectively prevents infection by lowering the load of pathogenic bacteria. In comparison, the effectiveness of the disinfectant (PUR) depends on its appropriate concentration and timing of application. It is not only limited to rearing water but is also applicable for decontaminating pond liners, tanks, and other paraphernalia.

Combination of entropy weighting and global stability index provides a potential strategy for monitoring the shelf-life of Litopenaeus vannamei during cold storage

Combination of entropy weighting and global stability index provides a potential strategy for monitoring the shelf-life of <i>Litopenaeus vannamei</i> during cold storage

The Growth and Hemocyte Analysis of the Shrimp (Litopenaeus vannamei) Induced by Different Concentration of Artificial Seawater and Water Extract Of Sea Grapes (Caulerpa lentillifera)

The Growth and Hemocyte Analysis of the Shrimp (Litopenaeus vannamei) Induced by Different Concentration of Artificial Seawater and Water Extract Of Sea Grapes (Caulerpa lentillifera)