Survival Rate Of Shrimp Research Articles

EVALUATION OF ENTEROCYTOZOON HEPATOPENAEI (EHP) IN FARMED PENAEUS VANNAMEI IN TAIWAN

Enterocytozoon hepatopenaei (EHP) was first described in Thailand in 2009 and has since been identified as a significant threat to the shrimp aquaculture industry. Recently, intracellular microsporidia were identified as a causative agent of hepatopancreatic microsporidiosis (HPM). To date, HPM has been listed as an emerging threat to shrimp farming industries because of reduced shrimp growth and survival rates which are considered to be a wasting disease. This study investigated the outbreaks of HPM in farmed Penaeus vannamei in Taiwan. Sixty-five shrimp samples were collected from Taiwan. The proportion of HPM-positive cases was 48% (31/65). Additionally, the gross signs in infected shrimp were stunted growth, sloughed hepatopancreas (HP), and lethargy. The smear impression on the HP also revealed the existence of large EHP spores. Nested-PCR findings identified that 9 cases were confirmed to be positive for the EhSWP1 gene in the first step and 22 cases tested positive for the second step. Phylogenetic analysis of EHP from Taiwan showed 100% similarity to EHP from Thailand, India, and the United States. Histopathological analysis of the HP revealed haemocyte infiltration and the presence of EHP spores in the hepatopancreatic tubule epithelial cells. These results demonstrated that EHP is the main cause in shrimp farms in Taiwan.

In Vivo Anti-Vibrio Evaluation of Sponge-Associated Bacteria on the Survival Rate of Litopenaeus vannamei Infected with Pathogenic Vibrio Species.

Sponge-associated bacteria are considered a rich source of bioactive compounds particularly to reduce the risk of Vibrio harveyi and Vibrio parahaemolyticus infection. The present study aimed to analyse the effectiveness of 19 isolates to control Vibrio infection in vivo. All 19 isolates displayed a non-pathogenic characteristic on shrimps (cell density of 106 cells/mL) as analysed using the pathogenicity test. The mortality caused by both Vibrio spp. on 50% of the shrimp population (LC50 value) had a cell density of 105 cells/mL as determined using the proportion interval method. On the basis of the challenge test, all isolates improved the survival rate of infected shrimps in diverse effectivities up to 89%, which was nearly 30% higher than the infected control. Two isolates coded as D6.9, and P5.20 reduced shrimp mortality after infection with Vibrio spp. 16S rRNA-based identification showed these isolates were closely similar to different genera of Bacillus and Staphylococcus. The extract derived from the most prospective isolate, D6.9, was dominated by 1-hydroxy-6-(3-isopropenyl-cycloprop-1-enyl)-6-methyl-heptan-2-one, hexadecanoic acid, 4-epicyclomusalenone [(24S)-24-methyl-28-norcycloart-25-en-3-one], and 2,4-dimethyl acetoacetanilide. This observation suggested these isolates characterised by in vivo anti-Vibrio activity need to be further developed as biocontrol candidates.

Toxicological effects of polystyrene nanoplastics on marine organisms

Nanoplastic (NP) is an emerging contaminant in recent years, and it has been detected in water and even in polar ice. Further verification of the toxic potential of NPs in marine organisms is needed so that the ecological threat can be minimized. This study investigated the effects of 0.1, 0.2, 0.5, and 1.0μg (g shrimp)−1 of polystyrene nanoplastics (PS-NPs) on immune and oxidative response in Litopenaeus vannamei (L. vannamei) and the survival rate was recorded everyday. After 7 days, the immune and antioxidant parameters were analyzed, and histopathology and accumulation of PS-NPs were observed. The results indicated that the survival rate of shrimp receiving > 0.5μg (g shrimp)−1 PS-NPs was remarkably decreased than that of the control. The immune response results indicated that phagocytic activity (PA) receiving different concentrations of PS-NPs was remarkably decreased than the control. Respiratory burst activity (RB) receiving different concentrations of PS-NPs was remarkably increased than the control. However, superoxide dismutase activity (SOD) receiving > 0.2μg (g shrimp)−1 of PS-NPs was remarkably decreased than the control. The oxidative response results indicated that SOD activity receiving different concentrations of PS-NPs was remarkably decreased than that of the control. The catalase (CAT) activity, SOD mRNA expression, and malondialdehyde (MDA) content receiving different concentrations PS-NPs was remarkably increased than that of the control. In addition, CAT mRNA expression receiving > 0.2μg (g shrimp)−1 of PS-NPs was remarkably increased than the control. The histopathology shows that different concentrations of PS-NPs cause muscle, hepatopancreas, midgut gland, and gill damage. These results indicate that PS-NPs cause toxicity to L. vannamei by immune disruption, increased oxidative stress, and histopathology damage.

THE APPLICATION OF YEAST AND LACTIC ACID BACTERIA IMPROVE GROWTH AND INTESTINAL STRUCTURE OF TIGER SHRIMP LARVAE Penaeus monodon Fab.

This study aims to investigate the effect of the different concentration of RABAL (yeast and lactic acid bacteria) probiotics on the survival, feed conversion, growth and intestinal cells changes of tiger shrimp Penaeus monodon Fab. larvae. This study used a Completely Randomized Design (CRD) method with 4 treatments and 4 replications. Tiger shrimp with average size of 0.02 g was randomly stocked in each container containing RABAL with concentration of 0 ppm (A/control), 75 ppm (B), 150 ppm (C), and 225 ppm (D) with frequency once a day for 30 days. Data were analysed using one way ANOVA. The result showed that the application of RABAL with different doses into the shrimp culture media significantly influences (P0.05) the growth and food conversion ratio of tiger shrimp feed but did not significantly affect (P 0.05) on the survival rate. The value of water quality parameters in this study were still at normal levels for tiger shrimp rearing. As conclusion, the application of probiotics RABAL with different concentrations have positive effect on the absolute weight, absolute length, specific growth rate, feed conversion ratio and intestinal villi surface area of tiger shrimp larvae, without adverse effect on the survival rate of tiger shrimp seed.

Corn fermented protein in production diets for pacific white legged shrimp Litopenaeus vannamei: Improved growth performance, health status and resistance to infection

Two separate trials were conducted to evaluate the use of a novel Corn Fermented Protein (CFP) on growth performance and feed utilization of Pacific white legged shrimp Litopenaeus vannamei in out-door pond conditions as well an independent pathogen challenge (Vibrio harveyi) test under controlled conditions following an internal feeding trial with varying inclusions of CFP. In out-door ponds, the 12% inclusion level of CFP to completely replace the use of corn gluten meal (CGM) was shown to support shrimp growth in the pond that was historically heavily infected with pathogen, including white spot syndrome virus (WSSV) and acute hepatopancreatic necrosis disease (AHPND). In an indoor growth trial parallel with the pond challenge study, CFP at the level of 6%, 12% and 18% at the expense of fish meal (FM), soybean meal (SBM) and CGM were also able to improve growth and several related parameters such as final body weight, percentage weight gain and thermal growth coefficient (TGC). The feed conversion ratios (FCR) for shrimp fed with CFP were also lower compared to the shrimp fed without CFP. Numerically, despite no statistical difference, survivability, and total haemocyte count were also elevated for shrimp receiving CFP. The challenge test results showed that the mean cumulative survival rate of shrimp injected with V. harveyi at the dose of 5 × 104 CFU shrimp−1 were higher in the group of shrimp fed CFP compared to the control treatment. Values for mean phagocytosis activity were superior for fermented corn-fed shrimp. Meanwhile, haemocyte profiles remained uniform across treatments and phagocytic index was significantly reduced at 18% inclusion level of CFP. Phenoloxidase activity post-challenge with V. harveyi was elevated in shrimp fed CFP at all levels. These findings suggest that 6 – 12% inclusion of CFP can be utilized as a novel ingredient for shrimp feed. Advocating for functional ingredients with characteristics that can support health and welfare of intensively farmed shrimp will be of strategic importance in the future for sustainable production of shrimp under intensive conditions.

WSSV exploits AMPK to activate mTORC2 signaling for proliferation by enhancing aerobic glycolysis

AMPK plays significant roles in the modulation of metabolic reprogramming and viral infection. However, the detailed mechanism by which AMPK affects viral infection is unclear. The present study aims to determine how AMPK influences white spot syndrome virus (WSSV) infection in shrimp (Marsupenaeus japonicus). Here, we find that AMPK expression and phosphorylation are significantly upregulated in WSSV-infected shrimp. WSSV replication decreases remarkably after knockdown of Ampkα and the shrimp survival rate of AMPK-inhibitor injection shrimp increases significantly, suggesting that AMPK is beneficial for WSSV proliferation. Mechanistically, WSSV infection increases intracellular Ca2+ level, and activates CaMKK, which result in AMPK phosphorylation and partial nuclear translocation. AMPK directly activates mTORC2-AKT signaling pathway to phosphorylate key enzymes of glycolysis in the cytosol and promotes expression of Hif1α to mediate transcription of key glycolytic enzyme genes, both of which lead to increased glycolysis to provide energy for WSSV proliferation. Our findings reveal a novel mechanism by which WSSV exploits the host CaMKK-AMPK-mTORC2 pathway for its proliferation, and suggest that AMPK might be a target for WSSV control in shrimp aquaculture.

Identification and characterization of a novel SoxB2 gene in Litopenaeus vannamei and its potential roles in response to ammonia-N stress and post-exposure recovery

Increased concentrations of ammonia-N can cause seriously physiological harm to crustaceans, especially farmed shrimp (Litopenaeus vannamei). Ammonia-N is generally removed by water change, and will gradually accumulate for unconsumed feed. However, the underlying adaptation mechanism of shrimp under such environmental conditions is still not fully understood. A novel Sox gene expressed differentially in previous comparative transcriptome studies was characterized in this study, designated as LvSoxB2–1. The LvSoxB2–1 encodes a protein of 420 amino acids, sharing the highest identity with the Chinese mitten crab (Eriocheir sinensis) Sox14b. The expression level of LvSoxB2–1 was higher in fertilized egg and cleavage stage of early embryonic development and declined in the blastula stage, which showed no significant difference compared with the subsequent stage. During larval development, LvSoxB2–1 increased significantly in nauplius stage III and zoea stage I and then restored to the initial level. LvSoxB2–1 was highly expressed in the gills, followed by eyestalks and brain ganglion. Results of subcellular localization have shown that LvSoxB2–1 is a nuclear-localized protein. In the ammonia-N stress and post-exposure recovery experiments, LvSoxB2–1 mRNA significantly increased in the gills, hepatopancreas, and hemocytes. The total hemocyte counts (THC) of shrimp was decreased through LvSoxB2–1 RNA interference (RNAi). Moreover, the inhibition of LvSoxB2–1 significantly exacerbated the hepatopancreas pathology and reduced the survival rates of shrimp exposed to ammonia-N. Dual-luciferase reporter assay confirmed the activation of the Wnt/β-catenin pathway by LvSoxB2–1. Under ammonia-N stress and recovery after exposure, LvSoxB2–1 silencing could decrease the expression of Wnt/β-catenin signaling molecules (β-catenin and Pangolin) and Rh protein in L. vannamei, with the higher malonyldialdehyde (MDA) and protein carbonylation (PCO) levels and hemolymph ammonia-N and urea contents. These results suggested that LvSoxB2–1 played positive roles in oxidative stress responses and ammonia-N excretion through the Wnt/β-catenin pathway.

Investigation of the effects of cup plant (Silphium perfoliatum L.) on the growth, immunity, gut microbiota and disease resistance of Penaeus vannamei

To investigate the effects of adding different concentrations of cup plant (Silphium perfoliatum L.) to the feed on the growth performance, hepatopancreas and intestinal microstructure, gene expression, enzyme activity, as well as intestinal microorganisms and resistance to Vibrio parahaemolyticus E1 and White spot syndrome virus (WSSV) infection of the shrimp, cup plant was added to the basal feed at 1%, 3%, 5% and 7% respectively, and fed the shrimp for 6 weeks. It was found that the addition of different concentrations of cup plant could significantly improve the specific growth rate and survival rate of shrimp, reduce the feed conversion rate, and improve the resistance to V. parahaemolyticus E1 and WSSV in shrimp, with the best effect of 5% addition. The tissue sections observations showed that the addition of cup plant significantly improved the hepatopancreas and intestinal tissues of shrimp, especially in alleviating the tissue damage caused by V. parahaemolyticus E1 and WSSV infection, but too high an addition (7%) could also cause side effects on the shrimp intestinal tract. Meantime, the addition of cup plant can also increase the activity of immunodigestive-related enzymes in the hepatopancreas and intestinal tissues of shrimp, and can significantly induce the up-regulation of immune-related genes expression, and it is positively correlated with the amount of addition in a certain range. In addition, it was found that the addition of cup plant has a significant regulating effect on the intestinal flora of shrimp, which can significantly promote the growth of beneficial bacteria such as Haloferula sp., Algoriphagus sp. and Coccinimonas sp., and inhibit pathogenic bacteria Vibrio sp., such as the number of Vibrionaceae_Vibrio and Pseudoalteromonadaceae_Vibrio in the experimental group were significantly reduced, and the lowest level in the 5% addition group. In summary, the study shows that cup plant can promote the growth of shrimp, improve the resistance of shrimp to disease, and is a potential green environmental feed additive that can replace antibiotics.

Lactobacillus plantarum isolated from kefir enhances immune responses and survival of white shrimp (Penaeus vannamei) challenged with Vibrio alginolyticus

Lactobacillus plantarum is known for its probiotics benefit to host, although the effects vary among strains. This study conducted a feeding experiment of three Lactobacillus strains, MRS8, MRS18 and MRS20, which were isolated from kefir and incorporated into the diets of shrimp to evaluate the effects of non-specific immunity, immune-related gene expression, and disease resistance of white shrimp (Penaeus vannamei) against Vibrio alginolyticus. To prepare the experimental feed groups, the basic feed was mixed with different concentrations of L. plantarum strains MRS8, MRS18, and MRS 20, which were incorporated at 0 CFU (control), 1 × 106 CFU (groups 8–6, 18–6, and 20–6), and 1 × 109 CFU (groups 8–9, 18–9, and 20–9) per gram of diet for an in vivo assay. During the rearing period for 28 days of feeding each group, immune responses, namely the total hemocyte count (THC), phagocytic rate (PR), phenoloxidase activity, and respiratory burst were examined on days 0, 1, 4, 7, 14, and 28. The results showed that groups 20–6, 18–9 and 20–9 improved THC, and groups 18–9 and 20–9 improved phenoloxidase activity and respiratory burst as well. The expression of immunity-related genes was also examined. Group 8–9 increased the expression of LGBP, penaeidin 2 (PEN2) and CP, group 18–9 increased the expression of proPO1, ALF, Lysozyme, penaeidin 3 (PEN3) and SOD, and group 20–9 increased the expression of LGBP, ALF, crustin, PEN2, PEN3, penaeidin 4 (PEN4) and CP (p < 0.05). Groups 18–6, 18–9, 2–6, and 20–9 were further used in the challenge test. After feeding for 7 days and 14 days, Vibrio alginolyticus was injected into white shrimp and observed the shrimp survival for 168 h. The results showed that compared to the control, all groups improved the survival rate. Especially, feeding group 18–9 for 14 days improved the survival rate of white shrimp (p < 0.05). After the challenge test for 14 days, the midgut DNA of survival white shrimps was extracted to analyze the colonization of L. plantarum. Among the groups, (6.61 ± 3.58) × 105 CFU/pre shrimp of L. plantarum in feeding group 18–9 and (5.86 ± 2.27) × 105 CFU/pre shrimp in group 20–9 were evaluated by qPCR. Taken together, group 18-9 had the best effects on the non-specific immunity, the immune-related gene expression, and the disease resistance, which might be due to the benefit of the probiotic colonization.

An effective biological treatment method for marine aquaculture wastewater: Combined treatment of immobilized degradation bacteria modified by chitosan-based aerogel and macroalgae (Caulerpa lentillifera)

Aquaculture has expanded significantly in recent years, and the effluent it produces has had a significant negative impact on the environment. The survival and growth rates of aquaculture products may impact by the eutrophication of the water body if the effluent from aquaculture is not handled. In this study, chitosan-based aerogel was used as a carrier to immobilize the degrading bacteria, and the adsorption capacity of the carrier material for methyl blue was 1.30 mg·g−1. The Caulerpa lentillifera was added to the shrimp tank at the same time as a biofilter, and a composite in-situ treatment system using microbes and macroalgae was built to handle the effluent from the mariculture industry to test the reduction rates of the nutrients from the wastewater. The outcomes demonstrated that the immobilized bacteria used had reduction rates of COD, NH4+ and NO2− in wastewater that were 48.82%, 9.14% and 40.74% greater than those of the free bacteria, respectively. The reduction effect of macroalgae for nutrients in wastewater is also very ideal, in which the reduction rates of TP and TN reach 32.43% and 74.94% respectively. When the immobilized degrading bacteria and macroalgae are combined, the reduction rates of COD, TN and TP in water reach 68.61%, 59.03% and 34.25%. At the same time, the survival rate of shrimp and the biomass of macroalgae have increased to a positive extent, with increases of 12.5% and 140%, respectively. These results demonstrate that the introduction of immobilized degrading bacteria and macroalgae into the shrimp culture system can effectively reduce the accumulation of nutrients in the shrimp culture system and have a positive impact in a variety of ways.

Effects of Bacillus strain added as initial indigenous species into the biofloc system rearing Litopenaeus vannamei juveniles on biofloc preformation, water quality and shrimp growth

The effects of Bacillus strains added as initial indigenous species into the biofloc system rearing Litopenaeus vannamei juveniles on biofloc preformation, water quality and shrimp growth under low salinity conditions were investigated. Three biofloc systems were designed (control, NT9 treatment with the addition of Bacillus subtilis NT9, and YB3 treatment with the addition of B. cereus YB3) for a 7-day biofloc preformation experiment and a 63-day shrimp culture experiment. The results showed that at the end of the biofloc-preformation stage, the biofloc volume in the YB3 treatment (13.6 ± 6.1 mL L−1) and control (7.1 ± 3.6 mL L−1) were 8.0 and 4.2 times that in the NT9 treatment (1.7 ± 0.7 mL L−1), respectively. During the culture experiment, the effects of strain YB3 on dissolved oxygen and total bacterial counts were significant (P < 0.05). The specific growth rates of shrimp in the NT9 treatment (4.25 ± 0.06% d−1) and YB3 treatment (4.03 ± 0.32% d−1) were increased by 22.8% and 16.5%, respectively, compared with that in the control (3.46 ± 0.69% d−1). No shrimp mortality was observed in the NT9 treatment. In the YB3 treatment, the survival rate of shrimp was 66.7 ± 21.1%, which was lower than that in the control (81.5 ± 16.4%, P > 0.05). The highest and lowest productivity were found in the NT9 treatment (3.14 ± 0.10 kg m−3) and YB3 treatment (1.85 ± 0.62 kg m−3), respectively. The addition of different Bacillus strains as initial indigenous species to the biofloc system had different effects. B. cereus YB3 promoted biofloc formation, and B. subtilis NT9 elevated shrimp growth performance.

The transcription factor CEBP homolog of Penaeus vannamei contributes to WSSV replication

The cellular transcription factors are known to play important roles in virus infection. The present study cloned and characterized a transcription factor CCAAT/Enhancer-binding protein homolog from the shrimp Penaeus vannamei (designates as PvCEBP), and explored its potential functions in white spot syndrome virus (WSSV) infection. PvCEBP has an open reading frame (ORF) of 864 bp encoding a putative protein of 287 amino acids, which contained a highly C-terminal conserved bZIP domain. Phylogenetic tree analysis showed that PvCEBP was evolutionarily clustered with invertebrate CEBPs and closely related to the CEBP of Homarus americanus. Quantitative real-time PCR (qPCR) analysis revealed that PvCEBP was expressed in all examined shrimp tissues, with transcript levels increased in shrimp hemocytes and gill upon WSSV challenge. Furthermore, knockdown of PvCEBP mediated by RNA interference significantly decreased the expression of WSSV genes and viral loads, while enhanced the shrimp survival rate under WSSV challenge. In silico prediction and reporter gene assays demonstrated that PvCEBP could activate the promoter activity of the viral immediate-early gene ie1. Collectively, our findings suggest that PvCEBP is annexed by WSSV to promote its propagation by enhancing the expression of viral immediate-early genes.

The Application of Microalgae Feeding Regime on Whiteleg Shrimp Culture in Each Stage: A Mini Review

Feed management in shrimp culture aims to improve the quality of shrimp organisms. The application of the feeding regime in shrimp culture has been developed to determine the best formulation of diet in order to maximize growth rate and survival rate of shrimp by increasing feed efficiency and minimizing waste. The application of the feeding regime is closely related to the understanding of the physiological and morphological aspects of shrimp from the larval stage to the adult stage. The success of the application of feed management with the application of the feeding regime will be a solution to the problem of the high costs of feed needed in shrimp culture. The best formulation of diet in shrimp culture in the N6-P3 stage is microalgae, at the M1-PL10 stage is zooplankton, and in the juvenile-adult shrimp stage is artificial feed. Microalgae can significantly increase the survival rate and growth rate of shrimp at the hatchery stage. This article aimed to examine the effect of the application of feeding regime using different diet formulations to produce the highest growth performance of shrimp in shrimp culture based on the morphological and physiological aspects of shrimp.

Brown sugar addition enhanced nutrient removal rates, growth performance, and bacterial community in a rice straw-based biofloc shrimp culture system

A 30-day culture trial was executed to ascertain the effects of brown sugar addition on nutrient removal, feed conversion ratio, growth performance, and microbial community in a rice straw-based biofloc shrimp system. Twelve indoor experimental barrels were supplied with juvenile pacific white shrimp (Litopenaeus vannamei) with a preliminary mean weight of ∼1.08 ± 0.35 g. The experimental groups comprised four biofloc treatments labeled as (Control-CT, SG1, SG2, and SG3), each with three replicates. The SG groups were the treatments with varying amounts of carbon source (brown sugar) addition. Each experimental barrel was stocked with 100 juvenile shrimps. To maintain the carbon: nitrogen ratio, brown sugar was added daily in varying amounts in the SG treatments but not in the control group (CT). The results demonstrated that the ammonium and nitrite‑nitrogen concentrations in the SG3 (0.45 and 0.34 mg/L) and SG2 (0.58 and 0.43 mg/L) groups were significantly (p < 0.05) lower than the Control (1.18 and 0.88 mg/L). Also, the highest nutrient removal rates for ammonium nitrogen (80%) and nitrite nitrogen (83.79%) were observed in the SG3 treatment. In addition, the SG2 group's feed conversion ratio (0.66) was statistically (p < 0.05) lower than the CT group's (0.83). Compared to the control setup (86%), the SG treatments recorded shrimp survival rates of over 90%. Furthermore, our results revealed that the most dominant microbial phyla in all treatments were Proteobacteria (71.60%), Bacteroidetes (26.60%), Actinobacteria (18.53%), Planctomycetes (8.30%), and Verrucomicrobia (2.40%) which played a significant role in nutrient cycling and promoting water quality. Overall, our study highlighted an innovative ecological farming system that recycles agricultural waste, minimizes inorganic nitrogen levels, and serves as an in-situ food source for sustainable shrimp production.

Glucose addition improves the culture performance of Pacific white shrimp by regulating the assembly of Rhodobacteraceae taxa in gut bacterial community

The family Rhodobacteraceae is a major core bacterial group in the gut of Pacific white shrimp (Penaeus vannamei) and its abundance can be stimulated by the carbohydrates (e.g., glucose) addition in biofloc-based culture systems. However, how glucose addition regulates Rhodobacteraceae assembly at a fine taxonomic resolution and its relationship with shrimp culture performance are unclear. Here, using full-length 16S rRNA gene PacBio sequencing, we explored fine-scale assembly mechanism of gut Rhodobacteraceae regulated by glucose addition. Glucose addition significantly enhanced the growth, survival rate, and feed efficiency of shrimps, and induced Rhodobacteraceae assembly consequently to create a more stable gut bacterial community, reflected by enhanced convergence and network stability as compared to those of the control. Five Ruegeria taxa were identified as potential probiotic candidates for improving shrimp culture performance. Meanwhile, the neutral model showed that positive host selection of gut Ruegeria taxa (primarily R. conchae and R. arenilitoris) from both water and gut metacommunities was enhanced by glucose addition, which stimulated deterministic assembly of gut Rhodobacteraceae. Moreover, differences in assembly processes of Rhodobacteraceae taxa at presumed strain-level within the same species (i.e., R. conchae) were observed, suggesting the necessity of revealing aquaculture bacterial assembly at the finer taxonomic resolution. Collectively, structural equation modeling demonstrated glucose addition improved shrimp culture performance largely by regulating the gut Rhodobacteraceae assembly. Our study provides insights into the assembly of gut Rhodobacteraceae stimulated by a basic regulatory measure in biofloc-based culture systems, holding the practical potential in managing a beneficial microbiota for shrimp culture.

Application of inorganic fertilizer combination with various kinds of organic fertilizer in the nursery phase of white shrimp (Litopenaeus vannamei)

The purpose of this research is to determine the effect of natural feed growth on the growth and survival rate of white shrimp, specifically in relation to the usage of inorganic fertilizers in conjunction with various organic fertilizers. The experimental design consisted of four treatments, each replicated three times. The treatments included a combination of urea, SP-36, and organic fertilizer derived from superintensive shrimp pond waste (Treatment A), a combination of urea, SP-36, and petroganic (Treatment B), a combination of urea, SP-36, and chicken manure (Treatment C), and a control treatment consisting of only urea and SP-36 without any organic fertilizer (Treatment D). Urea was administered at a dosage of 5.2 grams per container, SP-36 at a dosage of 2.6 grams per container, and organic fertilizer at a dosage of 52 grams per container. The factors that were monitored included the composition of plankton, the growth of benthic algae, the growth and survival of white shrimp, and the quality of pond water. The study’s findings revealed no statistically significant difference in the growth of live feed when inorganic and organic fertilizers were combined (P&gt;0.05). However, the survival rate of white shrimp exhibited a significant difference (P&lt;0.05). Using a mixture of inorganic fertilizer (namely urea and sp-36) and organic fertilizer, within the context of a super-intensive shrimp pond, yielded the most favorable outcome regarding white shrimp survival rate, with a recorded percentage of 94.67%.

Suplementasi HYPEROL untuk Peningkatan Pertumbuhan Udang Vaname (Litopenaeus vannamei)

The provision of quality feed is the most important factor determining the success of vannamei shrimp farming. The aim of this study was to evaluate the growth performance, survival rate and water quality of pacific white shrimp Litopenaeus vannamei after dietary administration of combination of calcium, magnesium dan vitamin D3. Shrimp were fed a control diet (without combination of calcium, magnesium dan vitamin D3 supplement) and four levels of combination of calcium, magnesium dan vitamin D3 supplementation i.e 0; 0.25; 0.50; 0.75; 1.00 mL Hyperol Kg-1 of feed. Larvae were reared in tank with a dimension of 40x25x30cm containing 4 L of disinfected seawater at a stocking density of 100 larvae m-2. In conclusion, the present study demonstrated that dietary supplementation of combination of at the concentration up to 10 mL Kg-1 could significantly improve growth and survival rate of Pacific white shrimp

PvML1 suppresses bacterial infection by recognizing LPS and regulating AMP expression in shrimp.

Toll and Toll-like receptors (TLRs) play essential roles in the innate immunity of Drosophila and mammals. Recent studies have revealed the presence of Toll-mediated immune signaling pathways in shrimp. However, the recognition and activation mechanism of Toll signaling pathways in crustaceans remain poorly understood due to the absence of key recognition molecules, such as peptidoglycan recognition proteins. Here, a novel MD2-related lipid-recognition (ML) member named PvML1 was characterized in Penaeus vannamei. We found that PvML1 shared a similar 3D structure with human MD2 that could specifically recognize lipopolysaccharides (LPS) participating in LPS-mediated TLR4 signaling. PvML1 was highly expressed in hemocytes and remarkably upregulated after Vibrio parahemolyticus challenge. Furthermore, the binding and agglutinating assays showed that PvML1 possessed strong binding activities to LPS and its key portion lipid A as well as Vibrio cells, and the binding of PvML1 with bacterial cells led to the agglutination of bacteria, suggesting PvML1 may act as a potential pathogen recognition protein upon interaction with LPS. Besides, coating V. parahemolyticus with recombinant PvML1 promoted bacterial clearance in vivo and increased the survival rate of bacterium-challenged shrimp. This result was further confirmed by RNAi experiments. The knockdown of PvML1 remarkably suppressed the clearance of bacteria in hemolymph and decreased the survival rate of infected shrimp. Meanwhile, the silencing of PvML1 severely impaired the expression of a few antimicrobial peptides (AMPs). These results demonstrated the significant correlation of bacterial clearance mediated by PvML1 with the AMP expression. Interestingly, we found that PvML1 interacted with the extracellular region of PvToll2, which had been previously shown to participate in bacterial clearance by regulating AMP expression. Taken together, the proposed antibacterial model mediated by PvML1 might be described as follows. PvML1 acted as a potential recognition receptor for Gram-negative bacteria by binding to LPS, and then it activated PvToll2-mediated signaling pathway by interacting with PvToll2 to eliminate invading bacteria through producing specific AMPs. This study provided new insights into the recognition and activation mechanism of Toll signaling pathways of invertebrates and the defense functions of ML members.

Effects of dietary Ginkgo biloba leaf extract on growth performance, immunity and environmental stress tolerance of Penaeus vannamei

Ginkgo biloba leaf extract (GBE) has been extensively used in the treatment of diseases due to its anti-inflammatory, antioxidant, and immunomodulatory effects. In aquaculture, GBE is widely used as a feed additive, which is important to enhance the immunity of aquatic animals. The current study evaluated the effects of adding GBE to the diet of Penaeus vannamei (P. vannamei) under intensive aquaculture. The GBE0 (control group), GBE1, GBE2, and GBE4 groups were fed a commercial feed supplemented with 0.0, 1.0, 2.0, and 4.0 g/kg GBE for 21 days, respectively. The results showed that dietary GBE could alleviate hepatopancreas tissue damage and improve the survival rate of shrimp, and dietary 2 g/kg GBE could significantly increase the total hemocyte count (THC), the hemocyanin content, the antioxidant gene's expression, and the activity of their encoded enzymes in P. vannamei. Furthermore, transcriptome data revealed that immunity-related genes were upregulated in the GBE2 group compared with the GBE0 group after 21 days of culture. Drug metabolism-cytochrome P450, sphingolipid metabolism, linoleic acid metabolism, glycerolipid metabolism, fat digestion and protein digestion and absorption pathways were significantly enriched, according to KEGG results. Surprisingly, all of the above KEGG-enriched pathways were significantly upregulated. These findings demonstrated that supplementing P. vannamei with 2 g/kg GBE improved its environmental adaptability by improving immunity, lipid metabolism, and detoxification. In this study, a comprehensive evaluation of the effects of dietary GBE on the intensive aquaculture of P. vannamei was conducted to provide a reference for the healthy culture of P. vannamei.

Effects of Bacillus pumilus BP-171 and Carbon Sources on the Growth Performance of Shrimp, Water Quality and Bacterial Community in Penaeus vannamei Culture System

A strain of Bacillus pumilus BP-171 with the ability of heterotrophic nitrification-aerobic denitrification was isolated from a shrimp culture pond and showed good denitrification ability under laboratory conditions. In order to investigate the effects of strain BP-171 and its combinations with different carbon sources, i.e., poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) and molasses, on the growth performance of shrimp, water quality and bacterial community in culture system of Penaeus vannamei, this experiment was set up. Four experimental groups were designed, i.e., group B applied with a single B. pumilus BP-171, the BP added with BP-171 and PHBV, the BM added with BP-171 and molasses, and the control DZ without the probiotic and carbon source. The results showed that the specific growth rate, final body weight, gross weight, feed efficiency rate and survival rate of shrimp in the BP and BM groups were better than those in the control (p &lt; 0.05), while the survival rate and gross weight of shrimp in group B were also better than those in the control (p &lt; 0.05). Among them, the best growth performance of shrimp was observed in the group BP. The concentrations of ammonia, nitrite, nitrate and total nitrogen were significantly lower in all treatment groups than in the control (p &lt; 0.05). The lowest concentrations of ammonia and nitrite were found in group B, while those of nitrate and total nitrogen were found in group BP (p &lt; 0.05). The concentrations of dissolved organic carbon and total organic carbon in both BP and BM groups were significantly higher than in group B and the control (p &lt; 0.05). Compared to the control, the abundance and diversity of the bacterial community in water did not change with the addition of probiotics and carbon sources. However, altered structure and predicted function, as well as improved stability of the ecological network of the bacterial community, were observed in water. In view of the above, the addition of B. pumilus BP-171 and PHBV significantly promoted the growth performance of shrimp, effectively improved water quality, and enhanced the stability of the ecological network of bacterial communities in water, which could have great potential for the application in intensive culture of P. vannamei.