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A high-performance liquid chromatography method coupled to tandem mass spectrometry was validated in order to study the pharmacokinetics of cefotaxime in shrimp hepatopancreases and plasma, as well as its withdrawal time related to a maximum residue limit (MRL) in shrimp muscle. Pharmacokinetics parameters were investigated through oral medication at a single dose of 25 mg/kg shrimp body weight and subsequent hepatopancreas and plasma cefotaxime concentration measurements at 0.5, 1, 2, 4, 8, 12 and 24 h after shrimp were fed with medication. The maximum concentration of cefotaxime was observed after one hour in the hepatopancreas (Cmax, 19.45 ± 2.10 mg/kg) and 4 h in plasma (0.184 ± 0.061 mg/L). Based on a minimum inhibitory concentration (MIC) of cefotaxime of 4.13 mg/L against Vibrio parahaemolyticus (known to cause acute hepatopancreatic necrosis disease (AHPND) in white leg shrimp), it was observed that the time during which the hepatopancreas cefotaxime concentration was above the MIC was 23 h. An every 24 h cefotaxime treatment could thus be effective in fighting against this bacterium in shrimp. The withdrawal time of cefotaxime was determined after shrimp were fed with medicated feed once a day and twice a day for three consecutive days. Shrimp muscle was collected on day 1 and day 3 during medication and 1, 3, 7, 14 and 21 days after medication was stopped. Considering an MRL of 50 μg/kg, the withdrawal times were 8.5 degree-days (corresponding to 6.9 h at 29.5 °C) after shrimp were fed with medicated feed once a day for 3 days and 95.5 degree-days (77.7 h at 29.5 °C) after shrimp were fed with medicated feed twice a day for 3 days. Moreover, histological analysis revealed that feeding shrimp with cefotaxime at the given dose in once- or twice-a-day treatments did not negatively impact the shrimp hepatopancreas. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the susceptibility of whiteleg shrimp (Litopenaeus vannamei) to Vibrio parahaemolyticus, a causative agent of acute hepatopancreatic necrosis disease at different salinities. Experimental shrimp were stocked at 40 individuals/tank containing 40 L of 15 ppt seawater. Salinities in the experimental tanks were adjusted to 10, 20, 25, 30, and 35 ppt, and remaining tanks (15 ppt) used as controls. The water temperature was maintained at 28°C. Three days after acclimatization to different salinities, shrimp were challenged with V. parahaemolyticus. Ten days after challenge, shrimp growing in 35 ppt salinity showed higher cumulative mortality than shrimp growing in 10 ppt. No significant difference occurred among the groups exposed to 15, 20, 25, and 30 ppt salinity. The median lethal time of challenged shrimp was 25.31 ± 4.06 hours at 35 ppt and significantly shorter than at 10 ppt (161.19 ± 4.60 hours) and at 15 ppt (91.30 ± 4.25 hours). The results suggest that whiteleg shrimp juveniles are more susceptible to V. parahaemolyticus when reared at 35 ppt salinity than at lower salinities. [ABSTRACT FROM AUTHOR]

Whiteleg shrimp (Litopenaeus vannamei) is a widely cultivated commodity in Indonesia. The high demand of white leg shrimp requires increased production. High stocking density in intensive cultivation and excessive amounts of feed are obstacles in white leg shrimp productiom. It will cause the shrimp to become stressed and susceptible to pathogen infection, one of them is ectoparasite. This research was conducted from August to September 2023 with the aim of determining the intensity and infestation degree of ectoparasite on white leg shrimp that cultivated in intensive ponds. The samples of white leg shrimp in this study were 50 individuals by purposive random sampling method. Observations were carried out by native method in the Cultivation and Anatomy Laboratory, Faculty of Fisheries and Marine, Airlangga University. The results showed that white leg shrimp cultivated in intensive ponds were infested by Zoothamnium sp. with intensity 184 individuals/tail, Vorticella sp. with intensity 268 individuals/tail and Epistylis sp. with intensity 235 individuals/tail. Each ectoparasite has a very severe infestation degree, but the most severe infestation was carried out by Vorticella sp. [ABSTRACT FROM AUTHOR]

Introduction: Aquaculture aims to provide stable environmental conditions for fish to be able to grow and protect it from stress and diseases. To guarantee a sustainable yield of fish species, well-balanced diets should be considered. For this purpose, diets supplemented with feed additives have won the interest of researchers who are concerned with the aquaculture field, the most important of which is chitosan, a cationic biopolymer, derived from the alkaline deacetylation of chitin; a natural polymer found in the exoskeletons of insects, crustaceans and fungal cell walls. Therefore, the purpose of this study was to examine the effects of using dietary chitosan in some immune indices and antioxidant defence system in Vannamei shrimp, Litopenaeus vannamei. Materials and Methods: For this purpose, 180 pieces of Vannamei shrimp with an average weight of about 4 g were prepared and kept for 2 weeks to adapt to the test conditions. We prepared 4 groups, each with three repetitions, including the basal diet of zero (control), 1 g (treatment 1 = T1), 2 g (T2) and 4 g (T3) chitosan per kilogram of feed in a completely randomized design for 8 weeks. At the end of the trial, samples were randomly taken from the rearing tanks and hemolymph indices including serum biochemical, immune and antioxidant indices were measured. Results and Discussion: According to the results, immune indices such as lysozyme and immunoglobulin increased significantly compared to the control group (p<0.05). So that in case of lysozyme, the highest amount was recorded in T2 (by adding 2 g/kg chitosan), while in immunoglobulin, the highest amount was observed in T1. Serum antioxidant activity such as superoxide dismutase (in T1 and T2) and catalase (in T1, T2 and T3) increased significantly compared to the control group (p<0.05). Also, the results of the serum biochemical analyses exhibited that only ALP enzyme recorded a significant difference (p<0.05), so that the highest value was observed in T3. According to the results, there was no significant difference (p>0.05) in ALT and AST enzymes among treatments. So that the highest amounts of these two enzymes were observed in T2 and the control group, respectively. Conclusion: The results of this study indicate the positive effects of chitosan on immune indices in Vannamei shrimp. Therefore, it is possible to recommend using chitosan as a natural and immune stimulant for culture of L. vannamei. [ABSTRACT FROM AUTHOR]

Simple Summary: Discovering alternatives to fish meal is crucial for maintaining the stability and rapid development of aquaculture. Rapeseed meal stands out as a promising substitute due to its low price, renewability, high protein content, and high yield. However, there are still several challenges associated with the use of rapeseed meal in aquatic feeds, one of which is anorexia. Rapeseed meal-induced anorexia has been reported in numerous fish studies, but its impact on crustacean feeding remains unelucidated. This study investigated whether rapeseed meal could cause anorexia in Litopenaeus vannamei, which is a crustacean that can accept a large amount of plant protein and is the largest cultured crustacean in the world. Considering the key role of neuropeptides in anorexia, transcriptome analysis was performed to identify six neuropeptides directly involved in rapeseed meal-induced anorexia. This study confirmed that rapeseed meal causes anorexia in L. vannamei, and the finding can be used to improve the application of rapeseed meal in shrimp feed. In addition, the neuropeptide response to rapeseed meal-induced anorexia in shrimp was explored, providing a theoretical basis for reducing rapeseed meal-induced anorexia via the endocrine pathway. Litopenaeus vannamei, with high plant protein acceptance and high global aquaculture production, is a potential species for rapeseed meal application. However, rapeseed meal has been associated with anorexia in fish, and whether the same occurs in L. vannamei remains unknown. This study demonstrated the effects of rapeseed meal on the feeding and anorexigenic endocrine of L. vannamei based on feeding behavior and transcriptomics. Soybean meal was replaced with fermented rapeseed meal (50%), and a significant increase in remaining diet and dietary discard was observed with a significant reduction in dietary visits. Transcriptome analysis revealed that the pathways involved in rapeseed meal-induced anorexia mainly included signal transduction, the digestive system, the sensory system, the endocrine system, phototransduction–fly, the thyroid hormone signaling pathway and pancreatic secretion. Moreover, this study further analyzed and identified seven neuropeptides involved in rapeseed meal-induced anorexia, and it explored the complex expression regulation strategies of these neuropeptides. In summary, this study confirmed through feeding behavior that rapeseed meal causes anorexia in L. vannamei, and it identified seven neuropeptides that were closely related to the anorexia process. [ABSTRACT FROM AUTHOR]

Abstract Vibrio parahaemolyticus is a significant causal agent of acute hepatopancreatic necrosis disease (AHPND), with huge production losses of white leg shrimp, Litopenaeus vannamei, cultivated globally, including aquaculture farms in the Mekong Delta of Vietnam. Controlling this disease is critical because of the worldwide expansion of antimicrobial‐resistant V. parahaemolyticus isolates. The purpose of this study was to determine the frequency of multi‐antibiotic resistance (MAR) in V. parahaemolyticus isolated from AHPND white leg shrimp extensively cultivated in Bac Lieu Province (Mekong Delta). Based on biochemical tests and toxR‐PCR positive detections, 34 V. parahaemolyticus isolates were identified. Antibiotic susceptibility examination revealed that most of the isolates were phenotypically multidrug resistant, including resistance to ceftazidime (100%) and amoxicillin (97.06%), followed by colistin (74%) and erythromycin (65%). These isolates were highly sensitive to doxycycline (94%), followed by florfenicol (74%) and flumequine (71%). There were 27 distinct MAR phenotypes detected among 34 isolates, with 14.71% of the isolates exhibiting the antibiotic profile AMO‐CEF‐CEP‐COL‐ERY, followed by 11.76% for each of the profiles AMO‐CEP‐TET‐COL and AMO–CEP–COL. In particular, 25 isolates (75%) were resistant to at least 5 (of the 12) antibiotics tested. A hierarchical clustering analysis of antibiotic‐resistant V. parahaemolyticus isolates indicated cross‐transmission across farms and its ability to survive in aquatic environments for extended periods (over 3 months). Our findings support the hypothesis that the variety of MARPs in V. parahaemolyticus is the result of human activities. Environmentally friendly therapy strategies should be used for the prophylaxis and treatment of V. parahaemolyticus infection.

A high-performance liquid chromatography method coupled to tandem mass spectrometry was validated in order to study the pharmacokinetics of cefotaxime in shrimp hepatopancreases and plasma, as well as its withdrawal time related to a maximum residue limit (MRL) in shrimp muscle. Pharmacokinetics parameters were investigated through oral medication at a single dose of 25 mg/kg shrimp body weight and subsequent hepatopancreas and plasma cefotaxime concentration measurements at 0.5, 1, 2, 4, 8, 12 and 24 h after shrimp were fed with medication. The maximum concentration of cefotaxime was observed after one hour in the hepatopancreas (Cmax, 19.45 ± 2.10 mg/kg) and 4 h in plasma (0.184 ± 0.061 mg/L). Based on a minimum inhibitory concentration (MIC) of cefotaxime of 4.13 mg/L against Vibrio parahaemolyticus (known to cause acute hepatopancreatic necrosis disease (AHPND) in white leg shrimp), it was observed that the time during which the hepatopancreas cefotaxime concentration was above the MIC was 23 h. An every 24 h cefotaxime treatment could thus be effective in fighting against this bacterium in shrimp. The withdrawal time of cefotaxime was determined after shrimp were fed with medicated feed once a day and twice a day for three consecutive days. Shrimp muscle was collected on day 1 and day 3 during medication and 1, 3, 7, 14 and 21 days after medication was stopped. Considering an MRL of 50 μg/kg, the withdrawal times were 8.5 degree-days (corresponding to 6.9 h at 29.5 °C) after shrimp were fed with medicated feed once a day for 3 days and 95.5 degree-days (77.7 h at 29.5 °C) after shrimp were fed with medicated feed twice a day for 3 days. Moreover, histological analysis revealed that feeding shrimp with cefotaxime at the given dose in once- or twice-a-day treatments did not negatively impact the shrimp hepatopancreas.

Vibrio parahaemolyticus is a significant causal agent of acute hepatopancreatic necrosis disease (AHPND), with huge production losses of white leg shrimp, Litopenaeus vannamei, cultivated globally, including aquaculture farms in the Mekong Delta of Vietnam. Controlling this disease is critical because of the worldwide expansion of antimicrobial‐resistant V. parahaemolyticus isolates. The purpose of this study was to determine the frequency of multi‐antibiotic resistance (MAR) in V. parahaemolyticus isolated from AHPND white leg shrimp extensively cultivated in Bac Lieu Province (Mekong Delta). Based on biochemical tests and toxR‐PCR positive detections, 34 V. parahaemolyticus isolates were identified. Antibiotic susceptibility examination revealed that most of the isolates were phenotypically multidrug resistant, including resistance to ceftazidime (100%) and amoxicillin (97.06%), followed by colistin (74%) and erythromycin (65%). These isolates were highly sensitive to doxycycline (94%), followed by florfenicol (74%) and flumequine (71%). There were 27 distinct MAR phenotypes detected among 34 isolates, with 14.71% of the isolates exhibiting the antibiotic profile AMO‐CEF‐CEP‐COL‐ERY, followed by 11.76% for each of the profiles AMO‐CEP‐TET‐COL and AMO–CEP–COL. In particular, 25 isolates (75%) were resistant to at least 5 (of the 12) antibiotics tested. A hierarchical clustering analysis of antibiotic‐resistant V. parahaemolyticus isolates indicated cross‐transmission across farms and its ability to survive in aquatic environments for extended periods (over 3 months). Our findings support the hypothesis that the variety of MARPs in V. parahaemolyticus is the result of human activities. Environmentally friendly therapy strategies should be used for the prophylaxis and treatment of V. parahaemolyticus infection. [ABSTRACT FROM AUTHOR]

Changes in protein quality during ice storage affects the muscle structure, the textural quality, functional properties and the eating quality. Dynamic viscoelastic behaviour and gelling properties ofmeat proteinsin relation to histological changes in white leg shrimp muscles were assessed for 14 days in ice storage. Reduction in Ca2+ ATPase activity of fresh myofibrillar protein (MFP), fading of myosin banding pattern and increased gapping in myofibrils were clearly observed with progress of storage. The quality indices of the shrimp muscle were well correlated with histological and functional properties as a function of ice storage. Solubility of fresh MFP was 86.76% which decreased to 77.06% on the 14th day of storage period. Emulsion capacity found to increase during storage period. Gel strength of white leg shrimp meat was low (81 ± 14 g cm) and further, reduced nearly 60% compared to fresh sample at the end of storage. The considerable reductions (from 535.77 kPa to 246.56 kPa) in storage modulus values were evident of diminishing elasticity and gelling ability of the meat due to ice storage.Therefore, this study usherd that the histological deterioration in myofibrils may be used as an indication of diminishing biochemical quality and gelling behaviour of the proteins.

Litopenaeus vannamei, with high plant protein acceptance and high global aquaculture production, is a potential species for rapeseed meal application. However, rapeseed meal has been associated with anorexia in fish, and whether the same occurs in L. vannamei remains unknown. This study demonstrated the effects of rapeseed meal on the feeding and anorexigenic endocrine of L. vannamei based on feeding behavior and transcriptomics. Soybean meal was replaced with fermented rapeseed meal (50%), and a significant increase in remaining diet and dietary discard was observed with a significant reduction in dietary visits. Transcriptome analysis revealed that the pathways involved in rapeseed meal-induced anorexia mainly included signal transduction, the digestive system, the sensory system, the endocrine system, phototransduction–fly, the thyroid hormone signaling pathway and pancreatic secretion. Moreover, this study further analyzed and identified seven neuropeptides involved in rapeseed meal-induced anorexia, and it explored the complex expression regulation strategies of these neuropeptides. In summary, this study confirmed through feeding behavior that rapeseed meal causes anorexia in L. vannamei, and it identified seven neuropeptides that were closely related to the anorexia process.

The Mekong Delta produces about 70 % of Vietnam's national aquaculture output, and water quality management is a key factor in maintaining high levels of production and profitability. Effective water management strategies depend on understanding the spatial and temporal variations in water quality along major waterways. Therefore, this study aimed to assess the spatial and temporal fluctuation of water quality in the waterways of five provinces with intensive aquaculture operations in the Mekong Delta. The study sites included two inland provinces (An Giang and Can Tho) where striped catfish, Pangasianodon hypophthalmus (Sauvage, 1878), is farmed, and three coastal provinces (Soc Trang, Bac Lieu, and Ca Mau) where white leg shrimp, Litopenaeus vannamei (Boone, 1931), and black tiger shrimp Penaeus monodon Fabricius, 1798, are cultured. At each sampling site, physicochemical parameters were monitored for 12 months on the main rivers which supply water to aquaculture systems. Water quality data were analysed and compared based on the coefficient of variation (CV), Pearson correlation coefficients to identify relationships among variables and principal component analysis (PCA) to identify 2-3 key parameters having the most significant influence on spatial and temporal variation in water quality in each province. BOD, COD, PO43-, S2-, NO2- and NO3- were highly variable (CV 40-120 %). Significant interrelationships ranged from -0.5 to 0.5 between many water quality parameters. Overall, water in most provinces was considered polluted. However, the water quality parameters, except for S2- and NO2-, were within acceptable levels specified by National Technical Regulation on Surface Water Quality for Protection of Aquatic Life. [ABSTRACT FROM AUTHOR]

Changes in protein quality during ice storage affects the muscle structure, the textural quality, functional properties and the eating quality. Dynamic viscoelastic behaviour and gelling properties of meat proteinsin relation to histological changes in white leg shrimp muscles were assessed for 14 days in ice storage. Reduction in Ca2+ ATPase activity of fresh myofibrillar protein (MFP), fading of myosin banding pattern and increased gapping in myofibrils were clearly observed with progress of storage. The quality indices of the shrimp muscle were well correlated with histological and functional properties as a function of ice storage. Solubility of fresh MFP was 86.76% which decreased to 77.06% on the 14th day of storage period. Emulsion capacity found to increase during storage period. Gel strength of white leg shrimp meat was low (81 ± 14 g cm) and further, reduced nearly 60% compared to fresh sample at the end of storage. The considerable reductions (from 535.77 kPa to 246.56 kPa) in storage modulus values were evident of diminishing elasticity and gelling ability of the meat due to ice storage. Therefore, this study usherd that the histological deterioration in myofibrils may be used as an indication of diminishing biochemical quality and gelling behaviour of the proteins. [ABSTRACT FROM AUTHOR]

Simple Summary: The aquaculture industry is facing several challenges, including water quality, stocking density and disease outbreaks due to bacterial pathogens. Pathogens and challenging conditions in aquaculture are common problems that cause mortality, reduce growth performance and consequently lead to high economic losses. To prevent those losses, antibiotics are often used for treatment or prophylaxis. With the increasing concern for antibiotic resistance and the demand to reduce the application of antibiotics, alternative solutions are needed. Incorporating probiotics in the diet can be one of the solutions to support feed efficiency as well as the resilience of the animals to pathogen pressure. The results of two experiments demonstrate that probiotic feed additives are promising strategies to improve shrimp production and provide increased protection against bacterial infection, independent of the diet formulation. Probiotic feed additives can support the gut health of shrimp and thereby improve performance, production efficiency and disease resistance. Two experiments in white leg shrimp aimed to investigate the effects of a multi-species probiotic feed supplement (AquaStar®, 3 g/kg feed, Biomin GmbH, Getzersdorf, Austria) in feed formulations with different marine meal levels (32% and 15%) on growth performance and resistance against Vibrio parahaemolyticus. Juvenile shrimp were stocked in a recirculating aquaculture tank system at a density of 20 shrimp/46.8 L and were fed diets with and without the probiotic supplementation for 8 weeks. Afterwards, a bath immersion with V. parahaemolyticus was performed and mortality was observed over a period of 14 days. Independent of the diet formulation, probiotic supplementation significantly improved the survival rate of the shrimp and the specific growth rate while decreasing feed consumption and feed conversion ratio when compared to the control (p ≤ 0.042). After the Vibrio immersion challenge, mortality was significantly decreased by 13.33% with probiotic supplementation in the high marine meal diet experiment (p = 0.042) and numerically decreased by 11.67% in the low marine meal diet experiment (p = 0.133). Overall, the results suggest that the beneficial effects of the probiotic can occur independently of the diet formulation. [ABSTRACT FROM AUTHOR]

Viral diseases have seriously restricted the healthy development of aquaculture, and decapod iridescent virus 1 (DIV1) has led to heavy losses in the global shrimp aquaculture industry. Due to the lack of effective treatment, early detection and regular monitoring are the most effective ways to avoid infection with DIV1. In this study, a novel real-time quantitative recombinase polymerase amplification (qRPA) assay and its instrument-free visualization improvement were described for the rapid detection of DIV1. Optimum primer pairs, suitable reaction temperatures, and probe concentrations of a DIV1-qRPA assay were screened to determine optimal reaction conditions. Then, its ability to detect DIV1 was evaluated and compared with real-time quantitative polymerase chain reactions (qPCRs). The sensitivity tests demonstrated that the limit of detection (LOD) of the DIV1-qRPA assay was 1.0 copies μL−1. Additionally, the presentation of the detection results was improved with SYBR Green I, and the LOD of the DIV1-RPA-SYBR Green I assay was 1.0 × 103 copies μL−1. Both the DIV1-qRPA and DIV1-RPA-SYBR Green I assays could be performed at 42 °C within 20 min and without cross-reactivity with the following: white spot syndrome virus (WSSV), Vibrio parahaemolyticus associated with acute hepatopancreatic necrosis disease (VpAHPND), Enterocytozoon hepatopenaei (EHP), and infectious hypodermal and hematopoietic necrosis virus (IHHNV). In conclusion, this approach yields rapid, straightforward, and simple DIV1 diagnoses, making it potentially valuable as a reliable tool for the detection and prevention of DIV1, especially where there is a paucity of laboratory equipment. [ABSTRACT FROM AUTHOR]

Currently, count size is applied globally as a grading standard to sell head-less shell-on farmed shrimp. Although count size does not indicate directly the quality of shrimp, the price of shrimp generally increases proportionally with the increase of shrimp size. The importance of the size of white leg shrimp has been previously reported, where a strong correlation was found between size and metabolome data. In this study, we aimed to improve the predictive power of the orthogonal projection to latent structure (OPLS) model by expanding the metabolite coverage using liquid chromatography mass-spectrometry (LC/MS) and gas chromatography-mass spectrometry (GC/MS) analysis. The training set consisted of 11 different-sized white leg shrimps from Indonesia and was validated in a step-wise manner by introducing an independent dataset consisting of commercial shrimp from the Japanese market. The first validation set consisted of commercial white leg shrimp, resulting in standard deviation error estimation and prediction values of 1.648 and 2.617, respectively. IMP and AMP, which are metabolites responsible for the umami taste in crustaceans, showed the highest variable importance in projection (VIP) scores and positively correlated with the increase in shrimp size. The second validation was carried out to evaluate the applicability of the size–metabolome relationship to other commercial penaeid shrimp species. The commercial black tiger shrimps with count sizes of 31/40, 21/25, 16/20, and 13/15 failed to predict the size of shrimp, suggesting that the importance of size in relation to the metabolome profile was rather species-specific. [ABSTRACT FROM AUTHOR]

The current study was carried out to assess the effects of using Bacillus subtilis-fermented rice bran (FRB) on water quality parameters, water microbial counts, growth performance, body composition, antioxidants/oxidants, and immunity biomarkers of white leg shrimp (Litopenaeus vannamei) reared at different salinities. Shrimp juveniles (0.51 ± 0.11 g) were distributed in triplicates into 27 1-m3 fiberglass tanks (1,000 animals/m3/each) and subjected to bifactorial treatments (three feeding types using FRB with three different salinity levels). After acclimation to different salinities (5, 15, and 35 g/L), under each salinity level shrimps received a 40% protein-commercial diet (100 CD) only, 50% commercial diet plus FRB (50 CD+FRB), or FRB only for 12 weeks. A half of each tank's water in the 100 CD groups was replaced daily with new water containing the same salinity level; no water exchange was done in the other two groups. Total ammonia-nitrogen, pH, and nitrite values of water in 50 CD+FRB and FRB tanks were significantly lower than those in 100 CD tanks (P < 0.05). The total bacterial and Bacillus sp. counts in the water of the 50 CD+FRB and FRB tanks were significantly higher; Vibrio sp. counts were significantly lower than the 100 CD treatment especially at 35 g/L salinity. The growth and yield of shrimp were significantly higher in tanks that received FRB only at a salinity of 35 g/L with zero water exchange. Interestingly, significant increases in crude protein, total lipids, and ash contents in the flesh of shrimp that received FRB only at 35 g/L salinity were observed. Furthermore, feeding type and/or water salinity significantly modulated antioxidants/oxidants (malondialdehyde [MDA], superoxide dismutase [SOD], and catalase [CAT]) and immune biomarkers (lysozyme [LYZ] and phenol oxidase [PO]). It is noted that antioxidants/oxidants significantly decreased as salinity levels increased, especially in tanks that received FRB only. Immune biomarkers were significantly higher in animals reared in FRB-based tanks than those that received artificial feeding. Their activities also significantly increased as salinity levels increased. Overall, the application of FRB in shrimp culture at 35 g/L salinity with zero water exchange could sustain considerably better growth and yield of white leg shrimp by saving feed supplementation and subsequently reducing the feeding cost. [ABSTRACT FROM AUTHOR]

Abstract Plant‐derived products have been suggested to partially replace fishmeal in aquafeed; however, often at decreased growth performance, inflammatory responses, and increased susceptibility to diseases. This study assessed the effects of the commercial phytogenic feed additive Digestarom PEP MGE on the growth, nutritional performance, and immune response of L. vannamei. Juvenile shrimp (N = 540) were stocked in 36 tanks (V = 100 L) for 63 days and fed one of the four experimental diets: (i) standard formulation (control, 24% fishmeal), (ii) low fishmeal diet (5%), (iii) low fishmeal diet plus 0.2 g/kg Digestarom PEP MGE, and (iv) low fishmeal diet plus 0.4 g/kg Digestarom PEP MGE. The results obtained after 63 days of feed supplementation suggest that the blend of essential oils tested compensated for the negative performance and health consequences of the low fishmeal diet. Particularly, the survival, FCR, total hemocyte count, and respiratory burst of the shrimp fed a low fishmeal diet supplemented with this phytogenic improved up to the levels recorded for shrimp fed a high fishmeal diet. Overall, results suggest that Digestarom PEP MGE can be incorporated into shrimp low fishmeal diets to compensate for the negative performance and immunological effects of partially replacing fishmeal with plant‐based protein.

As recurrent disease outbreaks impart economic adversity across the global shrimp farming sector in general, and in Asia in particular, clarifying determinants of outbreak susceptibility carries significance for sustainability in economic growth and social and environmental prospects. This study employs logistic regression to assess the probability of disease occurrence in intensive white leg shrimp (WLS) (Litopenaeus vannamei) aquaculture under the impact of explanatory factors grouped in (1) farmers' perceptions of climatic events, (2) adaptation measures (3) farmer biodata, (4) farm site characteristics, (5) biosecurity measures, and (6) culture method. The analysis was performed using a survey of 267 Vietnamese small-scale intensive shrimp farms in the Mekong region. Significant contributors to lowering the chance of shrimp disease occurrence include (1) regularly carrying out feed conversion ratio calculations, (2) increasing participation in training programs and extension services, (3) implementing adaptive measures related to changes in feeding schedules, and (4) increasing stocking density. The main risk factors increasing the chance of shrimp disease are the duration of the crop and more years in operation. This quantitative evidence contributes to identifying important focal points for policymakers and intensive shrimp farmers in monitoring and managing the shrimp industry under the potential impacts of climate change. • Shrimp farm survey identified factors influencing disease outbreaks. • Training, awareness of weather events, and adaptation affect disease risk. • Changing feeding practices and FCR monitoring reduce disease & pollution. [ABSTRACT FROM AUTHOR]

Probiotic feed additives can support the gut health of shrimp and thereby improve performance, production efficiency and disease resistance. Two experiments in white leg shrimp aimed to investigate the effects of a multi-species probiotic feed supplement (AquaStar®, 3 g/kg feed, Biomin GmbH, Getzersdorf, Austria) in feed formulations with different marine meal levels (32% and 15%) on growth performance and resistance against Vibrio parahaemolyticus. Juvenile shrimp were stocked in a recirculating aquaculture tank system at a density of 20 shrimp/46.8 L and were fed diets with and without the probiotic supplementation for 8 weeks. Afterwards, a bath immersion with V. parahaemolyticus was performed and mortality was observed over a period of 14 days. Independent of the diet formulation, probiotic supplementation significantly improved the survival rate of the shrimp and the specific growth rate while decreasing feed consumption and feed conversion ratio when compared to the control (p ≤ 0.042). After the Vibrio immersion challenge, mortality was significantly decreased by 13.33% with probiotic supplementation in the high marine meal diet experiment (p = 0.042) and numerically decreased by 11.67% in the low marine meal diet experiment (p = 0.133). Overall, the results suggest that the beneficial effects of the probiotic can occur independently of the diet formulation.

The polysaccharide-fucoidan plays a fundamental role in shrimp aquaculture by being used as a natural immunostimulant and dietary supplementation. In this study, Cystoseira trinodis fucoidan (FCT) was extracted, its structure was determined using FT-IR analysis, and its effect of fucoidan on growth performance and WSSV resistance in Litopenaeus vannamei was evaluated. Four experimental diets, including the control (without FCT), 0.1, 0.2, and 0.4% FCT, were formulated and fed to shrimps for 60 days. Next, they were exposed to WSSV, and their mortality rate was noted daily up to 20 days. The results of the growth experiment demonstrated a significant increase in the final weight, WG, and SGR, and a lower FCR in treatments than in control. During the challenge trial, 100% mortality was recorded in control within ten days. However, FCT-treated shrimps indicated a mortality increase from 43.33 to 75.00% during 20 days of infection. The immunological and biochemical parameters and the expression of immune-related genes in individuals fed the FCT-incorporated diet considerably (p < 0.01) improved over control before the challenge (0 days) and after the challenge on days 5, 10, 15, and 20. It was concluded that L. vannamei fed on diets supplemented with all concentrations of FCT (especially 0.4%) had improved the growth, immunological and biochemical parameters, and the expression of immune-related genes, as well as enhancing the resistance against WSSV. • This is the first study to reveal the impact of fucoidan extracted from brown seaweed, Cystoseira trinodis on the immunological and biochemical parameters and the expression of immune-related genes in Litopenaeus vannamei. • High levels of fucoidan in feed can significantly improve the growth performance, immunological and biochemical responses and immune-related gene expression in white leg shrimp. • Application of this dietary supplementation evidently enhanced disease resistance against WSSV in treated shrimps [ABSTRACT FROM AUTHOR]

Viral diseases have seriously restricted the healthy development of aquaculture, and decapod iridescent virus 1 (DIV1) has led to heavy losses in the global shrimp aquaculture industry. Due to the lack of effective treatment, early detection and regular monitoring are the most effective ways to avoid infection with DIV1. In this study, a novel real-time quantitative recombinase polymerase amplification (qRPA) assay and its instrument-free visualization improvement were described for the rapid detection of DIV1. Optimum primer pairs, suitable reaction temperatures, and probe concentrations of a DIV1-qRPA assay were screened to determine optimal reaction conditions. Then, its ability to detect DIV1 was evaluated and compared with real-time quantitative polymerase chain reactions (qPCRs). The sensitivity tests demonstrated that the limit of detection (LOD) of the DIV1-qRPA assay was 1.0 copies μL−1. Additionally, the presentation of the detection results was improved with SYBR Green I, and the LOD of the DIV1-RPA-SYBR Green I assay was 1.0 × 103 copies μL−1. Both the DIV1-qRPA and DIV1-RPA-SYBR Green I assays could be performed at 42 °C within 20 min and without cross-reactivity with the following: white spot syndrome virus (WSSV), Vibrio parahaemolyticus associated with acute hepatopancreatic necrosis disease (VpAHPND), Enterocytozoon hepatopenaei (EHP), and infectious hypodermal and hematopoietic necrosis virus (IHHNV). In conclusion, this approach yields rapid, straightforward, and simple DIV1 diagnoses, making it potentially valuable as a reliable tool for the detection and prevention of DIV1, especially where there is a paucity of laboratory equipment.

The study was conducted to determine the antibacterial activity of three herbal extracts: guava (Psidium guajava), leafflower (Phyllanthus urinaria L), beach daisy (Wedelia biflora (L.) DC ) against Vibrio spp. isolated from white feces syndrome infected shrimp in some provinces in the Mekong Delta. The antibacterial activity of the three herbal extracts was evaluated by the well diffusion method, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). The results indicated that there were 102 isolates in total of 378 shrimp samples which were clarified into 7 groups. Among these group, Vibrio alginolyticus group were the most abundant species with the percentage of 50 %, followed by Vibrio cholerae group with the percentage of 17.7%. The herbal extracts of P. guajava and P. urinaria L showed a broad - spectrum antibacterial activity against ten isolates which were selected for MIC and MBC test. The extract of P. urinaria L had the strongest antibacterial activity against V. harveyi CM3HPA2 and V. alginolyticus CM3IB2 (MIC of 0.2 mg/ml, MBC of 0.39 mg/ml). The obtained results indicated that the herbal extract of P. urinaria L will be a good candidate for reducing opportunistic pathogens Vibrio spp. abundant in gastrointestinal tract of shrimp.

Plant‐derived products have been suggested to partially replace fishmeal in aquafeed; however, often at decreased growth performance, inflammatory responses, and increased susceptibility to diseases. This study assessed the effects of the commercial phytogenic feed additive Digestarom PEP MGE on the growth, nutritional performance, and immune response of L. vannamei. Juvenile shrimp (N = 540) were stocked in 36 tanks (V = 100 L) for 63 days and fed one of the four experimental diets: (i) standard formulation (control, 24% fishmeal), (ii) low fishmeal diet (5%), (iii) low fishmeal diet plus 0.2 g/kg Digestarom PEP MGE, and (iv) low fishmeal diet plus 0.4 g/kg Digestarom PEP MGE. The results obtained after 63 days of feed supplementation suggest that the blend of essential oils tested compensated for the negative performance and health consequences of the low fishmeal diet. Particularly, the survival, FCR, total hemocyte count, and respiratory burst of the shrimp fed a low fishmeal diet supplemented with this phytogenic improved up to the levels recorded for shrimp fed a high fishmeal diet. Overall, results suggest that Digestarom PEP MGE can be incorporated into shrimp low fishmeal diets to compensate for the negative performance and immunological effects of partially replacing fishmeal with plant‐based protein. [ABSTRACT FROM AUTHOR]

cute Hepatopancreatic Necrosis Syndrome -AHPNSof cultured shrimp was first detected in China in 2009 and caused huge damage to shrimp farming in many countries including Vietnam. This study investigates the ability to inhibit Vibrio parahaemolyticuswhich causes hepatopancreatic necrosis of some Bacillusstrains. V. parahaemolyticusNT7 of this research was isolated from a white leg shrimp sample with hepatopancreatic necrosis in Ninh Thuan province and identified by biochemical methods. By the cross-steak and well-diffusion methods, the selected strain Bacillus polyfermenticusF27 showsthe largest diameter of 18.50 mm resistance to V.parahaemolyticus NT7.B. polyfermenticus F27strain caninhibitV. parahaemolyticus NT7. Besides, B. polyfermenticusF27 inhibits V. parahaemolyticusNT7 with co-cultured experiment and does not cause hemolysis. It is also safe for white leg shrimp seed with a 100% survival rate of the experimental treatments. The result of LD50 examination when infecting V.parahaemolyticus NT7 to white leg shrimp seed is 105CFU/ml. Through the host protectioncapability assessment of B. polyfermenticusF27, we found that itcanprotect white leg shrimp seed from V. parahaemolyticus.The findings show that strains of B. polyfermenticusF27 have the potential to produce probiotics for controland preventionof EMS/AHPNS of shrimps.

Nutrition and the use of valuable nutrients is one of the most important issues in the aquaculture industry. In this study, the algal species I. galbana and P. lutheri alone and in combination with C. mulleri were incorporated in the diet of white leg shrimp larvae (L.vannamei) and the survival and growth rate of shrimp were investigated. This research was carried out in Persian Gulf & Oman sea Ecological research institute in July 2016. The experiment was carried out from nauplii 6 stages to PL10 and the shrimp were fed six times a day over 16 days. Six treatments including single species of I. galbana, P. lutheri, and in combination with C.mulleri (as control) were in 3 replicates. At the end of the feeding period, the results of the experiment indicated that C treatment had the highest survival (72%) and the lowest survival was observed in B treatment (47%). There were significant differences among treatments (P≥ 0/05). The maximum (8.02mm) and the minimum (7.23mm) length were observed in F and B treatments, respectively. However, there was no significant difference among treatments (P≤ 0/05). The highest survival rate in salinities 45 and 53 was observed at 98% in E treatment and 95% in F treatment. No significant differences were observed in survival among treatments. Thus C.mulleri is an essential main species for feeding white leg shrimp larval stage and I.galbana can also be supplemented for increasing nutritional value that could be suitable to improve quality and growth factor of shrimp larvae.

This study examined the effects of different levels of dietary - Biotronic Top 3 on growth, feeding, and body biochemical composition of white leg shrimp, Litopenaeus vannamei reared at the Choebdeh Shrimp Culture Complex, Abadan for a period of 64 days. Shrimp with an initial average weight of 4.28+0.05g were stocked randomly in fifteen 300l polyethylene tanks at a density of 25 shrimp/tanks. Triplicate groups of shrimp were hand-fed to satiation four times a day using the experimental diet containing 0 (treatment 1, control), 0.5 (treatment 2), 1 (treatment 3), and 2 (treatment 4) grams per kilogram of Biotronic Top 3. Biometry was done at the beginning and the end of the experiment. After 64 days, shrimp receiving diets supplemented with Biotronic Top3 showed significantly better growth performance than those fed the control diet(P<0.05). The highest and the lowest weight gain, specific growth rate, and survival rate were recorded in treatments 4 and 1, respectively. Feed conversion ratio, protein efficiency ratio, and feed efficiency were significantly different between the treatments (P<0.05). The highest FCR and the lowest PER were recorded in treatment 1 and the lowest FCR and the highest PER were recorded in treatment 4. Feed efficiency showed a trend similar to that of PER. Morphometric indices (total length, carapace length, orbit length), condition factor and body biochemical parameters were significantly different between the treatments (P<0.05). The protein content was the highest in shrimp fed the diet containing Biotronic Top3. The highest and lowest lipid contents were recorded in treatments 4 and 1, respectively. Based on our results and under the rearing conditions used in this study, the inclusion of Biotronic Top 3 at the rate of 2g/kg diet is recommended for feeding white leg shrimp, Litopenaeus vannamei. [ABSTRACT FROM AUTHOR]

The conversion from black tiger shrimp farming and crop farming to white leg shrimp production is widespread in Vietnam’s Mekong Delta provinces. However, this conversion trend also contains many risks related to the technical aspects of the production process. The study mainly aims to estimate the technical efficiency of white leg shrimp farming. It also compares the technical efficiency of white leg shrimp farming between the traditional group that historically has cultivated white leg shrimp and the group that recently converted from black tiger shrimp and crops to white leg shrimp, in order to evaluate the efficiency and adaptability of shrimp farming. Primary data were collected by directly interviewing 99 farmers in traditional areas and 101 farmers in recently converted areas in the study sites and analyzed by using the stochastic frontier method. The calculated technical efficiency was around 72.9 percent, suggesting that farmers could increase their output level by about 27.1%, given constant inputs. There was no difference in the technical efficiency of the two groups, indicating that the converted farms have sufficient adaptability when switching to white leg shrimp farming. The output loss in farmers’ production is still very high, with an average loss of 1973 kg/hectare.

White leg shrimp (Litopenaeus vannamei) farming effluent contains pollutants that include high levels of organic matter (OM) nutrients and growth-promoting substances. This study investigated the effects of varied concentrations of white leg shrimp (Litopenaeus vannamei) farm wastewater 0, 50, 75 and 100%, on the survival rate (SR) of three finfish species: tilapia (Oreochromis niloticus), grey mullet (Mugil cephalus) and rabbit fish (Siganus guttatus) as part of screening their potential in removing organic matter from the effluent of white leg shrimp farming. The different initial levels of shrimp wastewater from 50% to 100% had no significant effect on the survival rate of tilapia and mullet; but the survival rate of S. guttatus significantly decreased with increasing shrimp wastewater (P

Processing technology is important for the export amd import of shrimp and should be selected with regard to the needs of the market and be accepted by GRASS. Therefore, this project was carried out to achievie a proper technology, to maintain chemical, bacterial and sensory qualities and also the safety of shrimp in terms of food hygiene, to increase the shelf life and to detect the proper concentration of 4-hexylresorcinol for processing white leg shrimp. This research evaluated the hypothesis of 4-hexylresorcinol being able to preserve frozen cultured white leg shrimp. The treatments included shrimp immersed in 4-hexylresorcinol (at concentrations of 0.15 % and 0.05 % for 10 minutes) and antioxidant-less shrimp. No Pseudomonas, Vibrio parahaemolyticus, Escherichia coli or Hydrogen disulfide-producing bacteria were observed in either experimental or control samples. Unlike the control samples, Coliform bacteria were not observed in the experimental samples. TVB-N, Trimethylamine, Thiobarbituric acid, Free fatty acids, Peroxide value, moisture, total bacterial counts and Staphylococci counts of experimental and control samples showed significant difference during the storage period (P0.05). The sensory quality and the shelf life of experimental samples showed significant difference compared to control samples (P0.05). based on the Iranian National Standards, the test samples had a good quality during the period of six months in frozen storage ( -18 oC) but the control samples lost their sensory quality in lower than one month.

This study was aimed at comparatively analyzing the sterols, tocopherols and fatty acids from edible flesh and processing waste obtained from three shrimp species, utilizing rapid liquid chromatography (LC)-atmospheric-pressure chemical ionization (APCI)-tandem mass spectrometry (MS/MS) and gas chromatography-mass spectrometry (GC-MS). Results revealed the presence of significantly (p < 0.05) high proportions of health-beneficial omega-3 (n3) polyunsaturated fatty acids (PUFAs) in Argentine red shrimp (34.3% in waste and 38.2% in the flesh), compared to black tiger shrimp (16.5–24.2%) and whiteleg shrimp (13.2–22.6%). Among sterols, cholesterol was found most dominant, accounting in the range 349.4 (white shrimp flesh) to 559.3 µg/g fresh weight (FW) (black shrimp waste). Surprisingly, waste was found to contain a substantially higher amount of α-tocopherol, for instance, 21.7 µg/g FW in edible flesh and 35.3 µg/g FW in the waste of black tiger shrimp. The correlation analysis indicated that shrimp with low total contents of lipids might have higher proportions of health-beneficial long-chain (LC)-n3-PUFAs eicosapentaenoic (EPA) and docosahexaenoic acid (DHA). The fat quality indices, including the high ratios of hypocholesterolemic (h)/hypercholesterolemic (H) fatty acids, and lowest values of the atherogenic index (AI) and thrombogenic index (TI) indicated the health-beneficial potential associated with fat intake from red shrimp. Overall, a significant amount of health-beneficial compounds in edible flesh of studied shrimp confers its extraordinary nutritional benefits. Moreover, considering the richness of processing waste with these compounds, their valorization can be prompted.

This study was conducted from May to August, 2015 in 5 communes including An Thanh Nam, An Thanh Ba, An Thanh Nhi, An Thanh Dong and Dai An. There were 150 households were interviewed directly through questionnaires constituting of technical and financial aspects of farming system and 5 capitals of their likelihood strategy. The results showed that white leg (WLS) is the more popular cultured species compared to tiger shrimp (TS) accounting for 80% of the total number of interviewed farmers (120 households). In particularly, the total water surface area spent for white leg shrimp culture was 0.63±0.56 ha/household and for tiger shrimp was 0.62±0.41 ha/household with the average pond areas were 0.33±0.17 and 0.35±0.14 ha respectively. The average of shrimp stocking density for WLS was 83 individual/m2 and 31 individual/m2for TS (P

Antimicrobials are important to treat diseases in aquaculture and the objective of this study was to evaluate the quality of antimicrobial products commonly used in white leg shrimp ( Litopenaeus vannamei ) aquaculture in Northern Vietnam. A total of 25 antimicrobial products were obtained from 20 chemical shops including 12 products declared to contain a single antimicrobial, nine products with a mixture of two different antimicrobials and four products containing a mixture of three different antimicrobials. Ultra High Performance Liquid Chromatography coupled to Mass Spectrometry was used to analyse the concentration of the declared antimicrobials. Results revealed that only 1/12 products with a single antimicrobial contained an active substance within ± 10% (accepted level of variation) of the concentration declared on the product label. More than half of the products contained antimicrobial concentrations within < 1.0% to 90% of the declared concentration. The majority of the products provided inadequate or incorrect information on specific diseases to be treated, instructions on how to prepare medicated feed, withdrawal time, as well as instructions about personal protection measures. The documented poor quality of antimicrobial products and inadequate labelling has negative impacts on effective disease treatment; contribute to development of antimicrobial resistance, and the use of such products is associated with food safety and occupational health hazards. There is an urgent need to strengthen diagnostic services, legislation and control of antimicrobial products in shrimp aquaculture and educate farmers on prudent antimicrobial use practices. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate bio-chemical composition, functional, and rheological properties of croaker fish (Johnius dussumieri), Indian squid (Loligo duvaucelii), and white leg shrimp (Litopenaeus vannamei) in fresh condition. The n-3 fatty acids were slightly higher in croaker fish (14.91 %) compared to that in Indian squid (13.59 %) and white leg shrimp (13.02 %). The solubility and viscosity of croaker fish proteins were significantly (p < 0.05) lower as compared to shrimp and squid proteins, while the emulsion capacity was higher for squid proteins. The histological study of squid muscles revealed a unique and strong arrangement of myofibrils. Dynamic viscoelastic behaviour of fresh meat of croaker fish and white leg shrimp revealed that transition from sol to gel took place between 48°C to 65°C and 39.93°C to 64.30°C, respectively, while in case of Indian squid, gel formation (increase in G') progressed mainly in two steps: the first step at low temperature range of 5-28.41°C and the second step over 45°C. Along with this, gel breakdown occurred in the range of 28-45°C. Our study suggested that the temperature range for sol to gel transformation differs from species to species considerably and hence, a specific temperature range may be determined to have maximum gelling ability for every fish species used as raw material for gel-based formulations. [ABSTRACT FROM AUTHOR]

[Display omitted] • This study provides an optimized protocol for a challenge by immersion with WSSV-NS in Penaeus vannamei post-larvae (PL). • The PL become susceptible to WSSV-NS at ≥50 mg body weight. • The well-defined challenge protocol will allow the development of virus control strategies for administration at early life stages. • This is the first report on variable WSSV susceptibility of three different weight ranges of P. vannamei within the post-larval life stage. White Spot Syndrome Virus (WSSV) continues to cause considerable loss to shrimp farmers globally with frequent outbreaks even in specific pathogen free Peneaus vannamei. Our studies showed that the bodyweight (BW) of PL has a bearing on their susceptibility to the virus. To test this hypothesis, PL of the same age group and family were grouped according to BW (10–20, 30–40, and 50–60 mg) and challenged through immersion route with two viral doses (106 and 107 virus copies/L of water). It was observed that the PL became susceptible to WSSV at ≥50 mg BW. In the 50–60 mg PL group, the higher challenge dose shows a sharp mortality curve with 100% mortality at 10 days post immersion, while the lower dose shows a steady increase in cumulative mortality that reaches 100% on the 13th day post immersion. The study also brings out that an in vivo viral load of approximately 3.5 to 4.5 × 107 WSSV copies/100 ng shrimp DNA results in mortality. This is the first report on the relationship between BW and WSSV susceptibility in shrimp PL. Also reported here is a quantitative assessment of WSSV infection in P. vannamei PL and an optimized challenge protocol. [ABSTRACT FROM AUTHOR]

This study aims to determine suitable photoperiod for growth of white leg shrimp in supper-intensive tank culture system applying biofloc technology. The experiment was randomly designed indoor with different photoperiod treatments, including (i) 24 hours Dark; (ii) 6 hours Light: 18 hours Dark; (iii) 12 hours Light: 12 hours Dark; (iv) 18 hours Light: 6 hours Dark and (v) 24 hours Light. The lighting treatments, it was set with a 55w compact fluorescent (light intensity ~ 6000 lux). Shrimp with initial weight at 0.84g and 4.45cm of body length were cultured at density of 150 inds/m3 in Biofloc system (C:N=15:1), with 300L of water volume, 15‰ of salinity. Results showed that after 90 days of culture, water quality were in suitable range for shrimp growth. Body weight (BW) of shrimp among treatments were from 18.28 to 22.96 g. In which, BW of shrimp in completely dark condition was the lowest and significantly different compared to the others (p3), not significantly different compared to 18 hours Light (2,23kg/m3 ) but significantly different compared to the others. Besides, shrimp in the treatments with Light showed stronger color compared to shrimp in completetly dark condition.

White leg shrimp ('Litopenaeus vannamei) farming effluent contains pollutants that include high levels of organic matter (OM) nutrients and growth-promoting substances. This study investigated the effects of varied concentrations of white leg shrimp ("Litopenaeus vannamei,) farm wastewater 0, 50, 75 and 100%, on the survival rate (SR) of three finfish species: tilapia ('Oreochromis niloticusj, grey mullet ("Mugil cephalus,) and rabbit fish (Siganus guttatusj as part of screening their potential in removing organic matter from the effluent of white leg shrimp farming. The different initial levels of shrimp wastewater from 50% to 100% had no significant effect on the survival rate of tilapia and mullet; but the survival rate of 5. guttatus significantly decreased with increasing shrimp wastewater (P<0.05). The results showed that the removal of BOD, COD and TSS occurred in the range of 66-83,68-81 and 30-54%; respectively and the removal efficiency of OM by mullet was higher than Tilapia in all treatments. The study also indicated that the reduction highest removal of BOD, COD and TSS was achieved being 83.1%, 80.7and 53,7% respectively, at the medium stocking density (25 fish/m2) of mullet. [ABSTRACT FROM AUTHOR]

Replacing live food with artificial diets in aquatic larviculture, especially in shrimp larvae not only is caused convenience feeding, but also in economical view is very important. With this object, in this survey, a density of 100.L-1 white leg shrimp larvae in 9 nutritional treatments each with three replicates were cultured in 20L tanks each one was held with 10L of 30% salty water using one air stone. The larvae were fed 4 times.day-1 with different diets, including live foods (Cheatoceros gracilis and Artemia nauplii), artificial diets (handmade and imported) and different combinations. The results showed that the growth rate and survival percentage in larvae fed with combination feed treatments, were more desirable than those fed with food and feed treatments and feeding with homemade and imported feeds alone, raised high mortality in shrimp larvae during the experiment. Also, it was denoted that even if the zoea larvae has been fed with live food, feeding with 100% artificial diets for the resting larviculture period won't be possible because of decreasing significantly in growth rate, total length and survival percent of shrimp larvae, compare to the other treatments. In addition, replacing partly of live food with artificial diet without adverse affects on growth and survival rates of white leg shrimp larvae will be possible and the observation supported that the handmade feed with given formulation, had more suitable results comparing to the imported one for mixing with live food economically. Therefore, we recommend that a mixture the formulated diet and algae plus Artemia nauplii is used for culturing white shrimp larvae.

The algae Ulva lactuca and Gracilaria parvispora are abundant in the Gulf of California, rich in nutrients, and may be used as a source of protein in balanced diets for shrimp. This study tests whether their meal, as a partial inclusion in diets for juvenile Litopenaeus vannamei, is feasible. Percentages of inclusion were 5, 10, and 15 %. Results showed that final weight, weight gain, and specific growth rate varied significantly among diets ( P < 0.05). There were significant differences in growth among the trials of amount of inclusion of meal when using U. lactuca ( P < 0.05), and no significant differences among the trials when using G. parvispora ( P > 0.05). In general, better results were obtained when using G. parvispora compared with U. lactuca. When compared to the control diet (without inclusion), diets that included 10 and 15 % U. lactuca meal yielded a significantly lower growth ( P < 0.05), but no significant differences were detected when using U. lactuca 5 % meal ( P > 0.05), suggesting the feasibility of inclusion to this limited percentage. No significant differences were detected between the control and the three treatments with G. parvispora, suggesting the possibility of using higher percentages of inclusion. We conclude that both seaweeds may be used as a component in preparing feed for juvenile L. vannamei. [ABSTRACT FROM AUTHOR]

Bidens alba and Plectranthus amboinicus are common medicinal plants. This study investigated the effects of a diet containing B. alba extract (BAE) and P. amboinicus extract (PAE) on the immune responses, growth, and their resistance to Vibrio alginolyticus in white leg shrimp (Penaeus vannamei). An in vitro experiment revealed that the BAE and PAE are nontoxic to white leg shrimp haemocytes, and the extracts increased phagocytic activity, superoxide anion (O 2 −) production, and phenoloxidase (PO) activity. In in vivo trials, shrimp were fed diets containing 10, 20, or 40 g of BAE (B1, B2 and B4) or PAE (P1, P2 and P4 group) per kg of regular feed for 28 days, and immune parameters were measured. All BAE and PAE groups exhibited enhanced nonspecific immune responses including increased total haemocyte count, phagocytic activity, O 2 − production rate, and PO activity. Shrimp fed the BAE or PAE diet for 7 days exhibited increased expression of Lysozyme (Lyz) , Penaeidin 2 (Pen2) , Penaeidin 3 (Pen3) , and Penaeidin 4 (Pen4). After a V. alginolyticus challenge, the treated shrimp exhibited higher survival rates than exhibited by those fed the control diet. The growth performance results of 56 feeding trials revealed that shrimp fed BAE or PAE at 20 g/kg (B2 or P2 group) gained significantly more weight and has a significantly higher specific growth rate than did those on the control diet. Thus, these results suggest that administration of 20 g of BAE or PAE per kilogram of feed can enhance immunity, growth, and resistance to V. alginolyticus in white leg shrimp. • BAE and PAE extract enhance shrimp immune responses. • AMP genes are detected as upregulated in the hemocytes of shrimp fed BAE and PAE. • Dietary BAE and PAE protected white shrimp against V. alginolyticus infection. • BAR and PAE supplementation in diets improved growth performance of shrimp. [ABSTRACT FROM AUTHOR]

The article discusses research on the antibiogram and heavy metal resistance pattern of vibrio alginolyticus in relation to its isolation from farmed white leg shrimp. The research was conducted with the use of 14 antibiotics which includes oxolinic acid, ampicillin, and fosfomycin. It notes the possible presence of fertilizers which consists of heavy metal residues as a factor for bacteria formulation of metal resistance genes in shrimps.

The conversion from black tiger shrimp farming and crop farming to white leg shrimp production is widespread in Vietnam's Mekong Delta provinces. However, this conversion trend also contains many risks related to the technical aspects of the production process. The study mainly aims to estimate the technical efficiency of white leg shrimp farming. It also compares the technical efficiency of white leg shrimp farming between the traditional group that historically has cultivated white leg shrimp and the group that recently converted from black tiger shrimp and crops to white leg shrimp, in order to evaluate the efficiency and adaptability of shrimp farming. Primary data were collected by directly interviewing 99 farmers in traditional areas and 101 farmers in recently converted areas in the study sites and analyzed by using the stochastic frontier method. The calculated technical efficiency was around 72.9 percent, suggesting that farmers could increase their output level by about 27.1%, given constant inputs. There was no difference in the technical efficiency of the two groups, indicating that the converted farms have sufficient adaptability when switching to white leg shrimp farming. The output loss in farmers' production is still very high, with an average loss of 1973 kg/hectare. [ABSTRACT FROM AUTHOR]

Although Litopenaeus vannamei is the most produced and researched shrimp species worldwide, there are no published studies evaluating the use of the microbial biomass, Novacq™, in L. vannamei feeds. This study investigated the effects of supplementing Novacq™ at 100 g kg−1 in practical and commercial feeds in postlarvae 12 (PL 12) and juvenile white leg shrimp. Three experiments were carried out. In Experiment 1, PL12 were fed for 21 days with a Control, Novacq™ or Commercial feed. The Novacq feed was equal in PL12 performance to the Commercial diet and superior to the Control (final individual weight = 0.169, 0.167 and 0.087 g; percentage weight gain = 8014, 7956 and 4091% for Novacq™, Commercial and Control feeds, respectively). No statistical differences in survival, coefficient of variation and daily feed offered were observed across dietary treatments. In Experiments 2 and 3 the performance of juvenile shrimp fed practical and Commercial feeds supplemented with Novacq™ for 42 days, respectively. In Experiment 2, Novacq™ feed outperformed the Control feed by improving survival (89 vs. 51%), final individual weight (7.4 vs. 3.5 g), weight gain (7.1 vs. 3.2 g), and percentage weight gain (1997 vs. 898%). In Experiment 3 supplementing Novacq™ into the Commercial feed improved performance (final individual weight = 6.4 vs. 5.5 g, weight gain = 6.0 vs. 5.1 g, and percentage weight gain = 1712 vs 1443%) and reduced the coefficient of variation (19 vs 53%). Shrimp fed feeds containing Novacq™ also displayed numerically reduced daily feed offered and estimated feed conversion ratio values in comparison to the other dietary treatments. Whole-body composition was similar across dietary treatments. In summary, supplementation of Novacq™ in practical and Commercial feeds improved growth and efficiency of PL12 and juvenile shrimp suggesting its validity as a useful feed additive in the nutrition of white leg shrimp. • Novacq™ addition improved growth and feed efficiency of postlarvae and juvenile shrimp. • Whole-body composition was not altered by Novacq™ supply. • Novacq™ appears to be a useful feed additive in L. vannamei nutrition. [ABSTRACT FROM AUTHOR]

This study was aimed at comparatively analyzing the sterols, tocopherols and fatty acids from edible flesh and processing waste obtained from three shrimp species, utilizing rapid liquid chromatography (LC)-atmospheric-pressure chemical ionization (APCI)-tandem mass spectrometry (MS/MS) and gas chromatography-mass spectrometry (GC-MS). Results revealed the presence of significantly (p < 0.05) high proportions of health-beneficial omega-3 (n3) polyunsaturated fatty acids (PUFAs) in Argentine red shrimp (34.3% in waste and 38.2% in the flesh), compared to black tiger shrimp (16.5–24.2%) and whiteleg shrimp (13.2–22.6%). Among sterols, cholesterol was found most dominant, accounting in the range 349.4 (white shrimp flesh) to 559.3 µg/g fresh weight (FW) (black shrimp waste). Surprisingly, waste was found to contain a substantially higher amount of α-tocopherol, for instance, 21.7 µg/g FW in edible flesh and 35.3 µg/g FW in the waste of black tiger shrimp. The correlation analysis indicated that shrimp with low total contents of lipids might have higher proportions of health-beneficial long-chain (LC)-n3-PUFAs eicosapentaenoic (EPA) and docosahexaenoic acid (DHA). The fat quality indices, including the high ratios of hypocholesterolemic (h)/hypercholesterolemic (H) fatty acids, and lowest values of the atherogenic index (AI) and thrombogenic index (TI) indicated the health-beneficial potential associated with fat intake from red shrimp. Overall, a significant amount of health-beneficial compounds in edible flesh of studied shrimp confers its extraordinary nutritional benefits. Moreover, considering the richness of processing waste with these compounds, their valorization can be prompted. [ABSTRACT FROM AUTHOR]