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This study assessed the performance of domesticated tiger shrimp Penaeus monodon postlarvae and mud crab Scylla paramamosain co‐cultured in 90 extensive rice‐shrimp ponds in the Mekong River Delta of Vietnam from 2022 to Sep 2023. Limited supplementary feeding was applied for only 20% of the studied ponds. Results show that ponds stocked with domesticated postlarvae produced significantly larger shrimps at harvest and had better postlarvae usage efficiency (P < 0.05) compared with those stocked with older postlarvae produced by wild‐caught broodstock. Furthermore, a combination of stocking domesticated postlarvae and using organic fertilizer for pond preparation and during the crop was found to significantly improve productivity by 28% and final harvest size by 67% (P < 0.05). Larger shrimps fetched 54% higher farm‐gate prices, thus significantly increasing gross revenue for farmers. Co‐culture of mud crab in rice‐shrimp ponds at low densities (0.2–0.7 pcs/m2) was popular and profitable. Productivity was 116–187 kg/ha/crop with a profit margin up to 92.8%. Income from mud crab was very similar to that from shrimp. The results of this study suggest that domesticated postlarvae of P. monodon should be used for stocking extensive systems, preferably in combination of using organic fertilizer to enhance natural foods. Further improvement of income and profit can be achieved if more attention is paid on crablet quality and quality improvement. [ABSTRACT FROM AUTHOR]

To further explore the impact of nutrient fortification on the ovarian secondary development of redclaw crayfish, four groups were set up: group ①, no feeding; group ②, formulated feeding; groups ③ and ④, formulated feed + nutrient bait. Results showed (1) the proportions of egg‐bearing shrimp in groups ③ and ④. 2) The weight growth rate of group ① was the lowest, the maturation coefficient of unripe shrimp in group ④ was the highest, and the egg‐holding rates in groups ③ and ④ were significantly higher than those of group ①. The hatching and survival rates of yellow eggs in group ④ were significantly higher than those in group ②. The hatching and survival rates of red eggs in groups ③ and ④ were significantly higher than those in group ①. (3) The weight gain rate of juveniles in group ④ was significantly higher than those of group ①. (4) Genes and proteins related to ovarian development were screened. In summary, group ④ had a higher proportion of egg‐holding shrimp, faster ovarian development, and a higher maturity coefficient. The hatching and survival rates of eggs, and the survival and weight gain rates of the offspring were also high. [ABSTRACT FROM AUTHOR]

Synthetic astaxanthin is an effective nutritional strategy for improving shrimp body color and promoting growth. However, the optimal amount of astaxanthin in feed also varies with the synthetic technology and purity. In the present study, five diets containing different doses of synthetic astaxanthin (0% (CON), 0.02% (AX0.02), 0.04% (AX0.04), 0.08% (AX0.08), and 0.16% (AX0.16)) were administered to Penaeus monodon (initial body weight: 0.3 ± 0.03 g) for 8 weeks. With an increase in astaxanthin content in feed, weight gain and specific growth rate increased initially and subsequently decreased, with the highest value appearing at AX0.08. Dietary astaxanthin supplementation obviously improved the carapace and muscle color by enhancing astaxanthin pigmentation. Meanwhile, the fatty acid profile was altered by dietary astaxanthin, as evidenced by a decline in palmitic acid proportion, along with an increase in n-3 polyunsaturated fatty acids (n-3 PUFA) contents in muscle. In addition, dietary astaxanthin supplementation regulated prawn's antioxidant capacity. In the hemolymph, the activities of glutamic pyruvic transaminase (GPT) showed a significantly decrease trend with linear effect. The activities of glutamic oxaloacetic transaminase (GOT) and the contents of malondialdehyde (MDA) were first downregulated and then upregulated with significantly quadratic pattern. In the hepatopancreas, the activities of superoxide dismutase (SOD) and the contents of MDA were significantly downregulated with the increase of dietary astaxanthin levels. Reduced glutathione (GSH) contents and catalase (CAT) activities were also significantly decreased in group AX0.08. Correspondingly, astaxanthin decreased GSH and MDA contents under transportation stress. Moreover, the mRNA expression of immune genes (traf6, relish, and myd88) were inhibited by dietary astaxanthin supplementation. Based on the results of polynomial contrasts analysis and Duncan's test, dietary synthetic astaxanthin is a suitable feed additive to improve the growth, body color, antioxidant capacity, and nonspecific immunity of P. monodon. According to the second-order polynomial regression analysis based on the weight gain, the optimal supplementation level of dietary astaxanthin was 90 mg kg−1 in P. monodon. [ABSTRACT FROM AUTHOR]

Macrobrachium rosenbergii holds significant importance in aquaculture within tropical and subtropical regions globally. An infection called infectious precocity virus disease (IPVD), caused by infectious precocity virus (IPV), has emerged in M. rosenbergii in China and causes significant economic losses. The diseased M. rosenbergii presents with the characteristics of sexual precocity and slow growth. Elaborating the route of transmission and host range of IPV is necessary to prevent the disease. Transmission of IPV to healthy M. rosenbergii can occur through the ingestion of IPV-infected tissue, immersion of viral filtrate, cohabitation with infected M. rosenbergii, or water-borne transmission in contaminated environment. Results showed that fertilized eggs and different growth and development stages (larvae Ⅰ–Ⅵ, postlarvae, juveniles, and adult prawns) from infected M. rosenbergii were negative for IPV, indicating that vertical transmissions did not occur. The results of artificial infection experiments showed that M. nipponense tested positive for the presence of IPV, but not in fishes Carassius auratus, Pangasius bocourti, Micropterus salmoides, and Oreochromis mossambicus, and crabs Scylla paramamosain and Eriocheir sinensis. IPV could cause slow growth in M. nipponense and mainly infected the second pereiopod, brain, eyes, and gills of M. nipponense. M. nipponense was found to be a new freshwater crustacean host for IPV. From December 2019 to March 2022, 260 M. nipponense samples in four regions were collected, including 230 M. nipponense IPV-positive samples according to nested PCR and 40 M. nipponense IPV-negative samples according to nested PCR. These findings could aid in preventing and managing IPV infections in crustaceans. [ABSTRACT FROM AUTHOR]

Nowadays, bacterial diseases caused by Vibrio spp. pose a significant obstacle to aquaculture growth, affecting socioeconomic development. The presence of pathogenic Vibrio spp. are gaining attention due to widespread mortality in fish and shellfish worldwide. This study investigates the distribution of virulence genes and their pathogenicity by experimentally infecting a healthy group of cultured shrimp, specifically Penaeus monodon. A total of 225 Vibrio spp. isolated from 210 cultured shrimp from various geographical regions in Peninsular Malaysia were examined, resulting in 13 Vibrio spp. being identified and characterized. According to virulence gene assessment, only eight of the 11 virulence genes were detected in the isolates, including chiA (89%), flaC (74%), tlh (72%), toxR (70%), luxR (40%), pirA (11%), pirB (11%), and hlyA (0.4%). Other virulence genes, such as tdh, trh, and ctxA, were not found in any of the isolates (0%). Then, three Vibrio isolates, including V. parahaemolyticus S12-3, V. campbellii S10-4, and V. rotiferianus S24-4, were selected for pathogenicity test based on highest number of virulence genes in each species. These species were subjected to immersion challenge test against postlarvae (PL) P. monodon approximately PL-20 with three different concentrations of 1 × 106, 1 × 107, and 1 × 108 CFU/mL. The V. parahaemolyticus S12-3 was determined to have lethal concentration 50 (LC50) 1 × 105 CFU/mL after 168 hr of exposure. The immersion challenge test resulted in a pale hepatopancreas and empty guts in P. monodon. Histopathological examination showed sloughing of epithelial cells in the hepatopancreatic tubule, hemocytic infiltration, massive vacuolation, and loss of hepatopancreatic tubule structure. Overall, the study demonstrated the virulence and pathogenicity of V. parahaemolyticus S12-3 toward P. monodon, which could be associated with its virulence properties. Furthermore, the current findings will be useful in developing microbiological risk assessments for shrimp farming and aquaculture management. [ABSTRACT FROM AUTHOR]

Chlorella pyrenoidosa is a widely used microalgae in the aquaculture process of Litopenaeus vannamei. In order to evaluate the effects of supplementing C. pyrenoidosa on water quality, shrimp growth performance, and biofilm bacterial community structure in L. vannamei aquaculture systems, C. pyrenoidosa suspension was supplemented in the precultured biofilm (PB) and water exchange (WE) culture systems. The results showed that supplementation with C. pyrenoidosa significantly increased the turbidity and the concentrations of total ammonia nitrogen (TAN) and nitrite nitrogen (NO 2 − ─N) in the PBC system (the PB system supplemented with C. pyrenoidosa), but had no significant effect on those in the WEC system (the WE system supplemented with C. pyrenoidosa). However, the TAN concentration of all systems remained at a low level (<0.1 mg/L) throughout the experiment. Additionally, supplementation with C. pyrenoidosa decreased the final concentrations of total phosphorus in the PBC and WEC systems by 15.74% and 23.33%, respectively. With the supplementation of C. pyrenoidosa, the final weight, final biomass, and average daily growth rate of L. vannamei increased, while the feed conversion ratio decreased. 16srRNA high-throughput sequencing results showed that the supplementation of C. pyrenoidosa to the PBC system resulted in a decrease in the relative abundances of Proteobacteria and Bacteroidetes and an increase in the relative abundance of Acidobacteria. Compared to those in the initial biofilm sample, the relative abundances of nitrifying bacteria, Nitrosococcus, Nitrosomonas, Nitrococcus, and Nitrospira, in PBCF (biofilm in the PB systems with C. pyrenoidosa) and PBOF (biofilm in the PB systems without C. pyrenoidosa) decreased from 10.18% to 3.05% and 0.75%, respectively. In conclusion, C. pyrenoidosa, as a supplement to the aquaculture systems, has practical application prospects. [ABSTRACT FROM AUTHOR]

Studies on socioeconomic, communication media usage, occupational, and sociopsychological attributes of farmers are prerequisite for planning, designing, and successful implementation of sustainable management strategies of a sector which is true for Penaeus vannamei shrimp farming also. The state of Andhra Pradesh in India ranks first in shrimp farming. However, Tamil Nadu state has a lot of potential and is slowly catching with third position, so the baseline profile of shrimp farmers of Tamil Nadu was collected through interviews with 316 shrimp farmers in Nagapattinam, Mayiladuthurai, Thanjavur, and Thiruvallur districts. Most shrimp farmers were men of middle-age, with experience ranging from 1 to 5 years with secondary school to graduate level education. About 89.36% of shrimp farmers had taken loans for the purpose of shrimp farming whereas 78.16% were depending on income from shrimp farming as a repayment source. The benefit–cost ratio of shrimp farming was 2.2 indicating profitability so 79.37% of them were able to save money. However, for 86.53% this was a major expenditure too indicating its vital role in their life. For acquiring information for shrimp farming, 40% relied on friends and 24% relied on fellow farmers. Shrimp farmers were well-versed with the present-era mass-media and through smartphones they acquired information from apps like YouTube. Innovation proneness, scientific orientation, and economic motivation were found to be high in about 30% of farmers. Proper planning is essential for sustainable shrimp farming and sustaining the socioeconomic benefits. The studied attributes play an important role in formulation, designing, and successful implementation of sustainable shrimp farming. [ABSTRACT FROM AUTHOR]

Microbial community inhabiting the intestine of the shrimp (Penaeus monodon) and their surrounding environments (e.g., water and sediment) is considered as a key contributing factor for the sustainable farming of shrimp. Indiscriminate application of antibiotics in aquaculture is a growing concern due to the emergence of antibiotic resistant bacteria (ARB), more specifically the antibiotic resistance genes (ARGs). The present study investigates the microbiome composition and 19 ARGs from four different shrimp farming systems; (i) cluster, (ii) extensive, (iii) semi-intensive, and (iv) improved extensive in the southwest coastal region of Bangladesh. In doing so, the study applied advanced 16S rRNA-based metagenomic sequencing to study the bacterial composition. Moreover, gene specific polymerase chain reaction (PCR) was employed to detect the ARGs in shrimp, water, and sediments of different farming systems. In the current study, bacteria from the phylum Proteobacteria and Firmicutes were predominant among the samples (n = 12) collected from the different farming systems followed by Actinobacteria, Bacteroidetes, and Cyanobacteria. Firmicutes was the predominant phylum in the gut of shrimp cultured in the cluster (relative abundance 53.33%) and semi-intensive (relative abundance 59.2%) culture systems. Results indicated that the bacterial community structure was significantly (p < 0.05) distinct among gut, sediment, and water samples as well as the farming systems. The shared operational taxonomic unit (OTU) in the sediment sample (16,495) was nearly double than the gut (7,931) and water (8,513) bacterial communities. The improved extensive farming system showed 1,289 (11.05%) shared OTUs among gut, sediment, and water followed by semi-intensive (6.87%), cluster (6.27%), and extensive (5.46%) farming system. Among the tested ARGs, sul1, cat, gyrA(C), tetA, tetC, tetX, ere(A), vanR, and dfrA1 were predominant in water and sediment samples. Semi-intensive farming system had the highest prevalence of ARGs (21.05%) while the lowest prevalence was found in extensive (5.26%) farming system. Overall, the study provides a comprehensive scenario of bacterial composition and growing emergence of ARGs in shrimp farming of Bangladesh. Therefore, the production strategy must focus on the alternatives of antibiotic for shaping the shrimp cultivation technique more sustainable. [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii has emerged as a significant hospital pathogen, quickly becoming resistant to commonly prescribed antimicrobials. The present survey was done to evaluate the prevalence, antibiotic resistance pattern, and distribution of antibiotic resistance genes amongst the A. baumannii strains isolated from fish, shrimp, and lobster samples. Four-hundred and fifty seafood samples (100 g each) were collected from Shiraz, Iran. Acinetobacter baumannii was determined using culture and biochemical tests. Pattern of antibiotic resistance and distribution of antibiotic resistance genes were determined using the disk diffusion and polymerase chain reaction, respectively. A. baumannii contamination rate amongst the examined seafood samples was 4.44%, with the higher contamination rate of fish samples (7.85%). A. baumannii isolates harbored the maximum resistance rate against tetracycline (85%), ampicillin (85%), gentamicin (70%), and erythromycin (60%). Resistance rates toward trimethoprim-sulfamethoxazole, ciprofloxacin, ceftazidime, and azithromycin were 55%, 45%, 35%, and 30%, respectively. The minimum rates of resistance were obtained against imipenem (10%) and chloramphenicol (15%). The most commonly detected antibiotic resistance genes were blaCITM (75%), blaSHV (70%), tetA (70%), qnrA (55%), blaVIM (50%), and aac(3)-IV (50%). aadA1, sul1, dfrA1, qnr, blaVIM, blaSIM, blaOXA-51, blaOXA-23, and blaOXA-58 genes were detected in 40%, 30%, 45%, 50%, 35%, 25%, 30%, and 20% of isolates, respectively. The role of seafood samples as a potential reservoirs of antibiotic-resistant A. baumannii strains was determined. However, further investigations are required to identify additional epidemiological features of A. baumannii in seafood samples. [ABSTRACT FROM AUTHOR]

This study compared and evaluated the effects of nine native macroalgae species on the tropic coast of China on the growth and physiological health performance of white shrimp (Litopenaeus vannamei). Nine hundred juvenile shrimps weighing 1.6 ± 0.02 g were fed with nine different types of macroalgae for 28 days. The experimental groups were as follows: Con (the diet without macroalgae), CRA (Caulerpa racemosa), CLA (Caulerpa lentillifera), CSS (Caulerpa sertularioides), CLM (Chaetomorpha linum), ULA (Ulva lactuca), GBE (Gracilaria bailiniae), ASA (Acanthophora spicifera), SVC (Sargassum ilicifolium var. conduplicatum), and BGE (Betaphycus gelatinae). Results showed that the growth performance of shrimps fed on the macroalgae meals was significantly higher than that of the control group (P < 0.05). The immune defense capacity (total hemocyte count, phagocytosis respiratory bursts, prophenoloxidase system, hemagglutination activity, and antibacterial and bacteriolytic activities) and antioxidant capacity (total antioxidant capacity, superoxide dismutase, catalase, glutathione peroxidase, and malondialdehyde) of L. vannamei fed on macroalgae meals were significantly higher than those of the control group (P < 0.05). Specifically, the shrimps in the ASA group had the significantly higher physiological health level than shrimps in the other macroalgae groups (P < 0.05), and the expression of immune and antioxidation-related genes was also significantly higher in the ASA group (P < 0.05). Principal component analysis (PCA) demonstrated that optimal growth and physiological health efficacy were observed in the ASA group. In summary, this study suggested dietary manipulation using macroalgae to improve the growth performance, immune performance, and antioxidant capacity of L. vannamei, with the optimal macroalgae for the diet being Acanthophora spicifera. [ABSTRACT FROM AUTHOR]

A 56-day feeding trial was performed to determine the effect of replacing fishmeal with 0, 25%, 50%, 75%, and 100% PBM (FM) on growth performance, digestive enzyme, and immunity of juvenile giant river prawn (Macrobrachium rosenbergii). Diets were fed in quadruplicate (50 prawns per replicate) to satiation (3–5% of their body weight). The finial weight, weight gain, and specific growth rate of prawns were significantly reduced P < 0.05 when 100% PBM was substituted for fish meal, whereas the remaining test diets showed no variation compared to the control P > 0.05 . There was no significant difference in survival rates. The moisture, crude protein, and crude fat of the prawn were unchanged P > 0.05 . The SOD activity, MDA content, and AKP activity of hemolymph did not change significantly. However, the ACP activity of all replacement groups decreased significantly P < 0.05 . The amylase enzyme activity in the intestine of prawn fed 25% of PBM increased significantly compared with the control group, while the trypsin and lipase activities were unchanged. This study showed that PBM up to 75% replacement group does not affect growth performance, and all replacement groups have no adverse effect on intestinal digestive enzyme activity and immunity in juvenile M. rosenbergii. Therefore, poultry by-product meal could replace fish meal by up to 75%. [ABSTRACT FROM AUTHOR]

A 12-day experiment was conducted to investigate the effects of Artemia enrichment with two experimental microalgal emulsions (formulated with selected fatty acid contents) on Penaeus vannamei postlarvae. For this purpose, 405,000 postlarvae (stage 1) were obtained from a commercial hatchery in Santa Elena, Ecuador, and distributed into nine fiberglass tanks. Postlarvae were fed for 12 days with three experimental diets (three tanks per treatment): treatment A (Artemia enriched with experimental microalgal emulsion A and dry diet), treatment B (Artemia enriched with experimental microalgal emulsion B and dry diet) and nonenriched Artemia (Artemia without enrichment and dry diet). At the end of the experiment, length (mm), coefficient of variation of population sizes, number of postlarvae in a gram of weight (PL-gram), biochemical composition, fatty acid profile, hepatopancreas perimeter, and histopathological hepatopancreas status of P. vannamei postlarvae (stage 12) were analyzed. To evaluate the status of the hepatopancreas, a categorization range (1–5) was created with different histological parameters such as number of B cells, vesicles around them, healthy tubules, and degradation tissues. Growth traits did not present differences between treatments; total length was 10.17 mm, 10.83 mm, and 10.27 mm for treatment A, treatment B, and nonenriched treatment, respectively, and PL-gram was 141.00, 162.00, and 142.33 for treatment A, treatment B, and nonenriched treatment, respectively. Biochemical composition of postlarvae (lipids, ash, and protein content) did not present differences between the three treatments. Significant differences were observed in the content of three essential fatty acids (DHA, DPA, and ARA) in Penaeus vannamei postlarvae fed with Artemia enriched with experimental emulsions. Thus, DHA content was significantly superior in animals fed with Artemia enriched with treatments A and B (9.80 ± 0.71 % and 9.75 ± 0.44 % , respectively) than in animals fed with unenriched Artemia (5.78 ± 0.68) (P < 0.05). Concerning arachidonic acid (ARA), treatments A and B showed 3.31 ± 0.20 % and 3.19 ± 0.09 %, respectively, higher than postlarvae fed with unenriched Artemia, 2.73 ± 0.04 % (P < 0.05). Regarding DPA content, treatments A and B reported higher values of MA and MB (0.81 ± 0.06 % and 0.86 ± 0.08 %, respectively), than unenriched Artemia (0.43 ± 0.02 %) (P < 0.05). Interestingly, the increase in DHA, DPA, and ARA contents in postlarvae coincided with the increase in hepatopancreas perimeter. In addition, a large number of B cells, a large number of healthy tubules, increased dilatation of the central tube, and a lower percentage of deteriorated tissue were observed in the hepatopancreas when postlarvae were fed with enriched Artemia. [ABSTRACT FROM AUTHOR]

Fried foods and frying oil are subjects that warrant the attention of researchers because of their high consumption. Indeed, frying conditions make these oils very sensitive to lipid oxidation which deteriorates the quality and nutritional properties of the food. In this study, we examined the effect of rosemary extract (ROE), known for its high antioxidant activity, in soybean oil used to fry breaded butterfly shrimp, by measuring the induction period with OXIPRES, total polar material (TPM), peroxide index (PI), and free fatty acids (FFA). This evaluation was performed in comparison with control oils without antioxidants. The results showed a significant difference between the oils according to the analyzed parameters, especially in the final hours of frying. The treatment of the oil with rosemary extract effectively delayed its oxidation, having lower levels in all the oxidation markers that were analyzed. It was also found that rosemary extract is able to reduce oil consumption by fried foods. Therefore, ROE ensures soybean oil a high stability against oxidation and a longer shelf life, making it a good natural alternative to synthetic antioxidants. [ABSTRACT FROM AUTHOR]

To better understand the size differentiation mechanism of adult male prawn Macrobrachium nipponense, transcriptome sequencing was performed from the second pereiopod, hepatopancreas, and muscle of adult male prawn M. nipponense with significant differences in size (large: 1.47 ± 0.12 g; small: 0.28 ± 0.04 g). A total of 46,557 unigenes with an average length of 1,312 bp were obtained. Based on pereiopod of large male (LP) versus pereiopod of small male (SP), muscle of large male (LM) versus muscle of small male (SM), and hepatopancreas of large male (LH) versus hepatopancreas of small male (SH), a total of 805, 473, and 1,037 significantly upregulated DEGs were identified, respectively. The KEGG pathway analysis indicated that pathways such as the PI3K-Akt pathway, the cAMP pathway, the Hippo pathway, and the Ras signaling pathway were enriched in all three comparisons, which may be key size regulators in adult male prawn M. nipponense. Furthermore, as potential candidates for size differentiation in adult male prawns, twenty-eight DEGs involved in these four pathways were screened out, and their expressions were verified by quantitative real-time PCR (qPCR). The results of this study preliminarily elucidate the molecular mechanism of male M. nipponense in size differentiation and provide a theoretical reference for improving the commercial size of cultured male prawn M. nipponense. [ABSTRACT FROM AUTHOR]

Water contamination, temperature imbalance, feed, space, and cost are key issues that traditional fish farming encounters. The aquaculture business still confronts obstacles such as the development of improved monitoring systems, the early detection of outbreaks, enormous mortality, and promoting sustainability, all of which are open problems that need to be solved. The goal of this study is to provide a machine learning (ML)-based aquaculture solution that boosts prawn growth and production in ponds. The study described a proposed framework that collects data using sensors, analyses it using a machine learning framework, and provides results like a preferred list of water quality (QOW) variables that affect prawn development and yield, as well as pond categorization into low, medium, and high prawn-producing ponds. In this study, we use eight distinct machine-learning classifiers to discover the driving elements that influence the development and yield of aquatic food products in ponds in terms of QOW variables, as well as three feature selection approaches to identify the aspects that have the largest impact on the pond's total harvest performance. To validate and obtain satisfying results, the suggested system was installed and tested. The average F score and accuracy when yield is employed as a harvest parameter are determined to be 0.85 and 0.78, respectively. The average merit ratings of temperature, dissolved oxygen, and salinity are significantly higher than those of the other QOW components. The temperature variations are greatest during the second, fourth, and seventh weeks. Temperature, salinity, and dissolved oxygen are the three QOW variables that have the largest influence on overall pond harvest performance, according to the data. Additionally, it has been discovered that a key QOW factor in separating high-yielding ponds from low-yielding ponds is the temperature change following stocking. [ABSTRACT FROM AUTHOR]

Selenoprotein is a feed additive that can overcome oxidative stress in intensive Pacific white shrimp (Litopenaeus vannamei) culture. This study evaluated the effects of selenoprotein supplementation at various doses on Pacific white shrimp's digestibility, growth, and health performance. The experimental design used was a completely randomized design consisting of four feed treatments, namely, control and treatments with selenoprotein supplementation of 2.5, 5, and 7.5 g kg feed-1 with four replications. Shrimps (1.5 g) were reared for 70 days and challenged for 14 days by the bacteria Vibrio parahaemolyticus (107 CFU mL-1). Shrimps used in the digestibility performance evaluation (6.1 g) were reared until sufficient quantities of feces were collected for analysis. Shrimp supplemented with selenoprotein exhibited superior digestibility, growth, and health performance compared to the control (P < 0.05). The use of selenoprotein at a dose of 7.5 g kg of feed-1 (2.72 mg Se kg of feed-1) was considered the most effective for increasing productivity and preventing disease attacks in intensive shrimp culture. [ABSTRACT FROM AUTHOR]

The study aimed to evaluate the influence of various parameters of the blanching and drying condition of small shrimp (Acetes) on some product quality parameters. Some criteria were assessed, such as salt content, astaxanthin content (ATC), and color of small shrimp. The results showed that the blanching time significantly affected the salt content. When increasing the blanching time, the salt content was found to increase from 17.35 ± 2.48 mg/g DW to 39.51 ± 0.45 mg/g DW. The astaxanthin content achieved the highest value (0.026 ± 0.001 mg/g DW) in a 2% salt solution. The study showed that the blanching and drying processes significantly affected the salt content, astaxanthin, and color of the small shrimp, and the optimized temperatures for blanching and drying were 70°C and 60°C, respectively. [ABSTRACT FROM AUTHOR]

Vibrio are known opportunistic pathogens of pond‐cultured fish and shrimp. This study determined the presumptive Vibrio count (PVC) and percentage composition of "beneficial" sucrose‐fermenting vibrios (SFVs) and "pathogenic" non‐SFVs in the water, sediment, gills and intestines of healthy tilapia Oreochromis niloticus collected every 2 weeks from Days 30 to 120 post‐stocking in brackish water earthen ponds. PVCs in water and sediment ranged from 102–104 CFU/ml/CFU/g while in tilapias' gills and intestines, PVCs ranged from 103–106 CFU/g and 102–106 CFU/g, respectively, with SFVs dominating in water, sediment, gills (≥50%), and intestines (≥80%) of tilapia. Because use of tilapia‐conditioned green water (TCGW) for shrimp's grow‐out culture has been reported effective against acute hepatopancreatic necrosis disease outbreaks caused by V. parahaemolyticus, PVC, SFVs/non‐SFVs (%), and V. parahaemolyticus count (VPC) in the recycled TCGW and Litopenaeus vannamei's hepatopancreas were also examined from stocking until 105 days of culture (DOC) in earthen ponds. PVCs ranging from 102–103 CFU/ml and 103–104 CFU/g were noted in water and shrimp's hepatopancreas, respectively. While non‐SFVs population in water varied, a downward trend typified by an abrupt 50% reduction was noted in hepatopancreas at DOC 42, and remained or further dropped until DOC 105. VPCs in water likewise varied (undetectable–102 CFU/ml) while in hepatopancreas, counts dropped to undetectable level from DOC 70 onwards. Current data illustrate that remarkable shift of SFVs' dominance in the water and concomitantly in shrimp's hepatopancreas, plays a pivotal role in regulating non‐SFVs proliferation in shrimp's hepatopancreas via competitive exclusion. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the use of recirculation and settling chamber in synbiotic multi‐trophic culture of Crassostrea sp. with Litopenaeus vannamei. Four treatments were tested: MONO (shrimp monoculture); integrated multi‐trophic aquaculture (IMTA) (shrimp and oysters in the same tank); IMTA‐R (shrimp and oysters in adjacent tanks with recirculation) and IMTA‐RS (shrimp and oysters in adjacent tanks with recirculation using settling chamber). Shrimp post‐larvae (pL10) and oyster juveniles (3.12 cm) were stocked at a density of 3000 pL m−3 and 200 oysters m−2, respectively, for 42 days. The IMTA treatments showed lower values of settleable solids, when compared to monoculture. However, the excessive removal in the IMTA‐RS increased the levels of TAN (1.15 mg L−1) and nitrite‐N (3.47 mg L−1). The weight and yield of shrimp (1.59 g and 4.63 kg m−3) and the weight of oysters (18.05 g) was significantly higher in the IMTA. Regarding the planktonic community analysis, significant difference was observed on abundance in relation to time and among treatments, where the initial samples and IMTA treatments, with lower values, differed from the 21st and 42nd days and MONO respectively. The results indicate the benefits of the integrated multi‐trophic culture application with the two species in the same productive unit for better water quality and greater shrimp growth. [ABSTRACT FROM AUTHOR]

Black tiger shrimp (Penaeus monodon) is a commercially important species. It is reported to have low reproductive maturation rates in captivity. To improve the production of this species via sustainable aquaculture, genetic techniques are required to improve its maturation rates. However, to date, reports on P. monodon reproduction at a transcriptional level are limited. To address this, we conducted transcriptome sequencing of the ovaries and testes of P. monodon using high‐throughput sequencing to identify sex‐related pathways and genes. A total of 75.74 Gb of clean data were generated from nine gonadal tissue libraries. We obtained 62,276 unigenes with a mean length of 1452 bp and N50 of 2423 bp. A total of 11,411 significantly differentially expressed genes (DEGs) were identified between the testis and developed ovaries. Enrichment analysis of the DEGs identified 415 significantly enriched GO terms and 106 enriched KEGG pathways. Genes related to the P. monodon ovaries were enriched in the steroid biosynthesis, mRNA surveillance, nucleocytoplasmic transport, oxidative phosphorylation and DNA replication pathways. Five upregulated and five downregulated ovarian genes were confirmed using RT‐PCR. This investigation has thus identified important sex‐related functional genes, GO terms and pathways in P. monodon. In particular, we identified several important genes and pathways related to gonadal development, such as GnRH/GnRHR‐like, Hsp90, PCNA, cathepsin L, Wnt signalling pathway and ovarian steroidogenesis pathway, which provide important insights into the mechanism analysis and sex regulation of shrimp gonadal development. The results will provide reference data for future research into the reproductive biology of shrimp, which will aid in improved black tiger shrimp breeding in captivity. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate different feeding rate ratios in a biofloc technology‐based aquaponics system employing sea asparagus (Sarcocornia ambigua) and Pacific white shrimp (Litopenaeus vannamei) in an 83‐day experiment. Two treatments were evaluated: 100 and 50 g feed m−2 day−1, which were achieved by doubling the plant production area from 0.4 m2 to 0.8 m2. Shrimps (1.39 g ± 0.06 g) were reared under an initial density of 250 animals m−3 in 800 L polyethylene tanks, while the plants were cultivated using nutrient film technique hydroponic benches which received water from the shrimp unit through a pumping system. The increase in plant production area allowed for a statistically significant increase in the plant final biomass in approximately 74% (p < 0.05), with the end result that plant productivity was not altered (p ≥ 0.05). Shrimp growth performance and the concentrations of nitrogen compounds and orthophosphate did not differ significantly between treatments (p ≥ 0.05). In conclusion, the reduction in the feeding rate ratio from 100 to 50 g m−2 day−1 did not impair plant productivity, which indicates that the efficiency of the system was improved, as a greater plant biomass was produced with the same amount of shrimp feed inputs. [ABSTRACT FROM AUTHOR]

Glass bottom boat (Gbb) is a member of the transforming growth factor β family that plays several physiological roles in arthropods, including in reproduction. Recently, Fenneropenaeus merguiensis's Gbb (FmGbb) was demonstrated to play a stimulatory role in vitellogenesis of the banana shrimp, but potential partners of FmGbb have not been identified. Therefore, this study aimed to identify proteins that interact with FmGbb and characterize their gonad‐regulating function. A yeast two‐hybrid assay revealed three potential candidates: peritrophin (FmPT), polehole‐like protein (FmPhl), and an uncharacterized protein. Expressions of FmPT and FmPhl were found mainly in the ovaries and significantly increased in the developing stages. However, in a GST‐pull down assay, there was no protein–protein interaction between soluble recombinant glutathione‐S transferase‐fused FmPT (GST‐rPT) protein and the recombinant FmGbb protein (His‐TF‐rgbb). The vitellogenesis stimulatory role of FmPT was then investigated both in vitro and in vivo. Ovarian explants treated with GST‐rPT showed no significant change of vitellogenin (Vg) expression, but the injection of GST‐rPT in ovaries and hepatopancreas of previtellogenic shrimp did induc Vg expression, suggesting a vitellogenesis stimulating activity of FmPT. Our findings show that FmPT has a novel role in vitellogenesis stimulation and has the potential to be developed as a gonad‐stimulating bioproduct for use in shrimp aquaculture. [ABSTRACT FROM AUTHOR]

Keywords: lactic acid; Macrobrachium rosenbergii; organic acids; prawns; Vibrio harveyi EN lactic acid Macrobrachium rosenbergii organic acids prawns Vibrio harveyi 6414 6418 5 11/04/22 20221201 NES 221201 INTRODUCTION The applications of organic acids as an alternative to harmful antibiotics in the diets of farmed aquatic animals have been gaining interest (Koh et al., 2016; Ng et al., 2009, 2015; Romano et al., 2015). GLO:7ZE/01dec22:are16094-fig-0001.jpg PHOTO (COLOR): 1 Effects of different dietary lactic acid (LA) concentrations on the total viable bacterial count (TVBC), lactic acid bacteria (LAB) and Vibrio spp. (CFU/g) in the hepatopancreas of Macrobrachium rosenbergii juveniles after 7 weeks. In the present study, results conclusively showed that dietary LA acted as a growth promoter to I M. rosenbergii i juveniles, even at the lowest level tested (0.2% LA) which augments well for the cost effectiveness of using LA in prawn feeds. [Extracted from the article]

To investigate the key genes affecting ovarian development in the ridgetail white prawn, Exopalaemon carinicauda, we cloned the full‐length cDNA of the CDK9 gene and discussed its role in ovarian development. Our results show that the gene has an open reading frame of 1155 bp, encoded 383 amino acids, and it has a conserved cyclin binding motif S_TKc. The open reading frame of CDK9 was expressed as a 43.96 Kda molecular weight protein. The phylogenetic tree analysis showed that the CDK9 gene has the highest homology with the CDK9 genes of Penaeus vannamei and Penaeus japonicus. The results of qRT‐PCR show that the CDK9 gene was also expressed in the eye stalk, stomach, heart, gill, intestine, muscle, ovary, hepatopancreas and ventral cord. The expression level was highest in the ovary, which was significantly different from the other tissues (p < 0.05). In the five stages of ovarian development, the expression level of the CDK9 gene was highest in stage I, which was significantly different from the other stages (p < 0.05). In situ hybridization tests showed strong expression signals in the membrane, cytoplasm and nucleus of oocytes and previtellogenic oocytes. Nevertheless, following the proliferation of oocytes, the expression signals became much stronger in the oocyte membrane and in the whole follicular cells located in the interstitial space. The RNA interference results show that the expression of the CDK9 gene significantly affects the expression of the Vg and VgR genes. Our findings suggest that CDK9 plays an important role in the synthesis and transportation of vitellin. [ABSTRACT FROM AUTHOR]

The giant freshwater prawn, Macrobrachium rosenbergii, is abundantly farmed in East China and Southeast Asia. To date, limited information exists on the relationship between protein and astaxanthin, and the antioxidation and non‐specific immunity functions. This study was conducted to investigate the effects of dietary protein and astaxanthin levels on growth, hepatopancreas antioxidant capacity and non‐specific immune response of prawns. Further, the interaction between protein and astaxanthin was determined. In total, 1800 juveniles were randomly allocated into nine treatments with four replicates in 36 net‐cages. Nine iso‐lipidic diets were formulated with three levels of astaxanthin (0, 100 and 200 mg kg−1) and protein (350, 380 and 410 g kg−1) respectively. Feeding trials lasted for 72 days. The results demonstrated that survival rate, feed coefficient, protein efficiency and body composition did not differ significantly among treatments (p > 0.05), and the weight gain and specific growth rates disposed in their protein levels in diets by 410 g kg−1 were markedly higher than the other two levels (p < 0.05). There was no significant difference in antioxidant capacity of hepatopancreas among different levels of protein (p > 0.05). The activities of acid phosphatase, alkaline phosphatase and glutathione peroxidase in hepatopancreas decreased with upgraded content of astaxanthin in diets (P < 0.05). Overall, this study implies that dietary protein levels are the key factor impacting growth performance and feed utilization, when combined with astaxanthin in diets, an interaction effect may partially occur on antioxidant enzymatic activities. However, excessive supplementation of astaxanthin may cause negative impacts on some immune‐related enzymatic activities. [ABSTRACT FROM AUTHOR]

Gamma irradiation was applied to extend the shelf life of ready‐to‐eat shrimp chili paste stored at ambient temperature. Doses of 2–8 kGy did not affect aw, pH, color, and antioxidant properties of shrimp chili paste. Noticeable change in TBARs was noticed at 4 kGy, but panelists gave similar sensorial acceptability scores among samples. Gamma irradiation at 4 kGy could completely eliminate Escherichia coli intentionally inoculated in shrimp chili paste. However, gamma irradiation at 8 kGy was recommended because it could only sterilize RTE shrimp chili paste in cooperation with panelists overall acceptance. The RTE shrimp chili paste irradiated at 8 kGy was microbiologically safe throughout 6 months of ambient storage, whereas non‐irradiated chili paste was spoiled with a bacterial count above 6 log cfu/g. During storage with the presence of oxygen, alteration of color values, and increasing in lipid oxidation were noticed. However, panelists still accepted irradiated RTE shrimp chili paste at the end of storage. Novelty impact statement: Gamma irradiation is recommended as an alternative process to extend the shelf life of RTE shrimp chili paste under ambient condition without modification of product qualities and storage conditions. Gamma irradiation could replace chemical food preservatives and thermal process, which demolished aroma volatiles of chili paste. Important hindrances in terms of preparation hassle and short shelf‐life at ambient condition of RTE chili paste are resolved. Thus, potential markets in Southeast Asian, Asian, USA, and Europe could be expanded. These insights could be profitably applied to create other convenient and travelable condiments and table sauces. [ABSTRACT FROM AUTHOR]

The application potential of spirulina meal in aquaculture feeds has been well summarized in several descriptive reviews. Nevertheless, they converged on compiling results from all possible relevant studies. Little available quantitative analysis regarding the pertinent topics has been reported. This quantitative meta-analysis was performed to investigate the influences of dietary spirulina meal (SPM) addition on responsive variables in aquaculture animals, including final body weight (FBW), specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), condition factor (CF), and hepatosomatic index (HSI). The pooled standardized mean difference (Hedges' g) and 95% confidence limit were computed to quantify the primary outcomes based on random-effects model. The sensitivity and subgroup analyses were carried out to evaluate the validity of the pooled effect size. The meta-regression analysis was conducted to investigate the optimal inclusion of SPM as a feed supplement and the upper threshold of SPM usage for substituting fishmeal in aquaculture animals. The results indicated that on the whole, dietary SPM addition significantly improved FBW, SGR, and PER; statistically decreased FCR of animals; had no significant influence on CF and HSI. The growth-enhancing effect of SPM inclusion in the form of feed additive was significant; however, the effect was indistinctive in the form of feedstuff. Furthermore, the meta-regression analysis displayed that the optimal levels of SPM as a feed supplement in fish and shrimp diets were 1.46%-2.26% and 1.67%, respectively. Additionally, up to 22.03%-24.53% and 14.95%-24.85% of SPM as fishmeal substitute did not have a negative effect on growth and feed utilization in fish and shrimp, respectively. Therefore, SPM is a promising fishmeal substitute and a growth-promoting feed additive for sustainable aquaculture of fish and shrimp. [ABSTRACT FROM AUTHOR]

Shrimp culture and its export are growing fast in India in tandem with the global demand for protein‐rich seafood. Farmers are always seeking newer technologies and cultural practices to alleviate risks and remain profitable and sustainable. One of the practices that is gaining prevalence in recent years is Penaeus vannamei culture in lined ponds in brackish water and low saline environments. Our study aims to understand the differences in physicochemical and chemical parameters between lined and earthen ponds in simulated experiments and field studies and weighs the economic benefits. Earthen ponds exhibited lower pH fluctuations than lined as soil functions as a buffer against pH variations. The key differentiators were the lower metabolites and higher nutrients in the lined ponds leading to a healthier pond environment. It was complemented by lower vibrio load in the lined ponds, reducing the threat of diseases significantly. Comparatively, 12.5% higher survival rate and 9% higher growth rate were evidenced in the earthen ponds. Economically, lining material increases the initial capital cost and the income per culture was lower due to marginally lower survival and growth rates in lined ponds. However, this reduced profitability was more than offset by the possible higher number of cultures per year and reduced time between cultures. The economic analysis of average culture data established economic advantage of culture in lined ponds over earthen ponds with an incremental Benefit Cost ratio of 2.15. Ultimately, the choice of lined versus earthen culture depends on the investment and risk potential of the farmer. [ABSTRACT FROM AUTHOR]

Identification of spatial gradient in the vulnerability of white leg shrimp production to climate change is imperative in the formulation and implementation of suitable adaptive measures. A composite vulnerability index was computed by employing 36 variables pertaining to exposure (11), sensitivity (11) and adaptive capacity (14) dimensions to map the extent of vulnerability in white leg shrimp production across Indian states. Based on its magnitude, the vulnerability index was categorized into three groups, namely low, moderate and high. Results showed that the mean composite vulnerability index was 0.65 and ranged from 0.34 to 0.99 indicating that there was a strong spatial pattern. Among the nine states, Goa (0.99), Kerala (0.84) and Odisha (0.77) were highly vulnerable; Gujarat (0.75), Karnataka (0.57) and West Bengal (0.56) were moderately vulnerable; and Tamil Nadu (0.54), Andhra Pradesh (0.46) and Maharashtra (0.34) were less vulnerable to shrimp production. About one‐fourth of the production and culture area of white leg shrimp were in moderate and highly vulnerable regions. The impact of climate change on shrimp production is diverse but can be reduced by implementing adaptive measures—suitable policies and investment plans—which should be region‐specific. [ABSTRACT FROM AUTHOR]

Of several isolates from saline‐tolerant tilapia exhibiting anti‐vibrio activity, an isolate that demonstrated inhibitory activity with the biggest zone of inhibition against the shrimp pathogens, Vibrio harveyi and V. parahaemolyticus were chosen and investigated in this study. The isolate showed significant inhibition against the shrimp pathogens, V. harveyi and V. parahaemolyticus in a competitive assay. Upon 16S rRNA sequencing, the isolate was identified as putative Proteus mirabilis (MJA 2.6S). P. mirabilis (MJA 2.6S) exhibited extracellular protease, cellulase and amylase activities. Pathogenicity tests showed that it was not pathogenic to the shrimp even at the highest concentration of 108 CFU ml−1. Further, P. mirabilis (MJA 2.6S) improved growth and survival, stimulated higher phenoloxidase and bactericidal activities in the shrimp host and protected it from V. harveyi experimental infection. In addition, the isolate P. mirabilis (MJA 2.6S) significantly reduced the ammonia level of the pond water samples in vitro. Taken together, the results clearly showed the strong probiotic potential of P. mirabilis (MJA 2.6S) in shrimp and hence further studies are needed to determine its wider application as a probiotic in P. monodon culture. [ABSTRACT FROM AUTHOR]

The study aimed to develop a hot air‐assisted continuous microwave (HAMW) drying system and evaluate the drying of shrimp under microwave radiation. The drying system comprised of a drying chamber with a conveyor belt of dimension 1.5 × 0.5 m, magnetron of 1.45 kW to generate microwaves at frequency of 2450 ± 50 MHz, hot air generation system with air heater of 1 kW and axial fan of 50 W and other controls. Moisture content of shrimp was reduced from 80.55% to 16.5% within 3.5 h of drying. Volumetric heating effect of microwaves resulted in reduction of drying times. Effective moisture diffusivity of microwave‐dried shrimp was found to be 6.7 × 10−7 m2/s. Page model was the suitable fit for the data under study (R2 = 0.998454, RMSE = 0.0.01552 and χ2 = 0.000134). The drying efficiency and specific energy consumption for hot air‐assisted microwave drying of shrimp were calculated to be 35.71% and 1.75 kWh/kg, respectively. Water activity, rehydration ratio and shrinkage of the dried shrimp samples were 0.552%, 2.51% and 14.14%, respectively, with maximum color retention. Proximate and microbiological analysis of fresh and dried shrimp were carried out and were found to be under safe limits. The developed HAMW drying system was found to be suitable for shrimp drying under controlled conditions. Practical applications: Hot air‐assisted microwave (HAMW) drying system was developed to cater drying of shrimp under controlled conditions with lower drying times. Specific energy consumption (1.75 kWh/kg), drying efficiency (35.71%) and effective moisture diffusivity (6.7 × 10−7 m2/s) during drying was found to be superior to convective drying. Evaluation of quality parameters of dried shrimp such as rehydration ratio (2.51), shrinkage (14.14%), water activity (0.552) and total plate count (2 × 104 CFU/g) was falling under acceptable limits. The study suggests HAMW drying system as a potential means of drying shrimps for large‐scale commercial production. [ABSTRACT FROM AUTHOR]

Sodium metabisulfite is a chemical compound used to reduce melanosis of shrimps. However, this chemical compound has been associated with several human diseases and negative environmental impacts. Therefore, this study aimed to develop, characterize, and apply a coating and film based on natural and not toxic compounds. A chitosan‐based coating and a film containing acerola fruit powder were developed and characterized for various physicochemical and microstructural properties. The presence of acerola altered the chitosan interactions, hence, the chitosan film containing acerola had fewer crystal structure, reducing its hydrophobicity. Furthermore, the presence of acerola imparted an orange color in chitosan film when compared with chitosan film without acerola (transparent). The chitosan solution containing acerola was as effective as sodium metabisulfite solution in controlling the melanosis and lipid oxidation of the shrimps. The developed chitosan coating containing acerola can be used to control melanosis during shrimp storage and to reduce or to eliminate the use of the metabisulfite. Novelty impact statement: The active coating based on chitosan and acerola fruit is a new alternative to control melanosis of shrimps during storage at 5°C. Hence, the use of this eco‐friendly active coating could reduce the use of chemical toxic compounds such as sodium meta‐bisulfites. [ABSTRACT FROM AUTHOR]

A 60‐day feeding trial was conducted to evaluate the optimum dietary lipid level in terms of growth performance, digestive enzymes and hemato‐biochemical parameters of white‐leg shrimp, Penaeus vannamei juveniles in inland ground saline water (IGSW) of 15 ppt salinity. The shrimps (avg. wt., 4.04 ± 0.03 g) were randomly distributed in six groups in triplicates (15 shrimps/tank, 290 L), viz., TCL40 (40 g/kg lipid), TCL60 (60 g/kg lipid), TCL80 (80 g/kg lipid), TCL100 (100 g/kg lipid), TCL120 (120 g/kg lipid) and TCL140 (140 g/kg lipid). Six semi‐purified hetero‐lipidic (40‐140 g lipid/kg), hetero‐caloric (376–426 Kcal DE/100 g) and iso‐nitrogenous (400 g crude protein/kg) diets were prepared and fed to respective groups four times daily. Weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR), and protein efficiency ratio (PER) showed higher quadratic relations (R2 = 0.97, 0.98, 0.94 and 0.87, respectively) to dietary lipid levels (p < 0.05) with enhancing dietary lipid up to 60 g/kg. Whole body moisture and lipid contents exhibited a high linear (R2 = 0.87 and 0.98) and quadratic (R2 = 0.88 and 0.98) (p < 0.05) inverse relationship with enhancing dietary lipid levels up to 140 g/kg. Hemolymph hemocyanin, serum total protein and glucose level did not differ significantly (p > 0.05), but the TCL60 group showed significantly (p < 0.05) higher serum cholesterol and triglyceride levels. Serum osmolality, osmoregulatory capacity, and branchial Na+/K+‐ATPase activity was similar (p > 0.05) among the groups. Hepatopancreatic lipase and amylase activity significantly (p < 0.05) increased, but trypsin activity did not vary significantly (p > 0.05) among the groups. Second‐degree polynomial analysis with WG, SGR and FCR indicated that a 55.80–58.80 g lipid/kg diet is optimum for P. vannamei juveniles in IGSW of 15 ppt salinity. [ABSTRACT FROM AUTHOR]

Polychaete is considered the best maturation diet for penaeids; however, fluctuating supply and quality warrant detailed studies to understand the specific maturation‐promoting factors present in polychaete. Indian white prawn, Penaeus indicus, was fed diets supplemented with different fractions of Marphysa sp. extracts. Fractions, such as the total soluble fraction (TSF), neutral lipid fraction (NLF), and polar lipid fraction (PLF), were incorporated in the maturation diet at 0.25, 0.50, and 1.00% following a 3 × 3 factorial design. One group was fed with basal diet (BD), and another was fed with fresh squid, mussel, and polychaete, serving as the control. After a 30‐day feeding trial, results showed that the inclusion of polychaete extracts in the diet significantly improved P. indicus maturation compared to groups fed BD and control with 40% maturation rates (MR) (p = 3.4 × 10−4). MR was optimum in groups receiving diets supplemented with ≥0.5% TSF (70.00% ± 0.00) and NLF (60.00% ± 5.77). Similar improved MR was achieved in treatments receiving ≥0.25% PLF supplementation (60% ± 0.00). Accordingly, relative expression of ovarian vitellogenin mRNA of broodstock fed under 0.25 and 0.50% PLF group was 4.44 and 3.96 folds higher than BD, respectively (p = 0.003). No significant differences were detected in the broodstock survival, latency period, hepatosomatic, and gonadosomatic indices. Biochemical content analyses showed no significant differences among the nine treatments except for broodstock's higher ovary protein content in the TSF group (p = 0.037). This study highlights PLF as the most potent component of the polychaete extract in promoting gonad maturation in P. indicus maturation supplemented at a 0.25% optimum inclusion level. [ABSTRACT FROM AUTHOR]

Mathematical representation of the growth of organisms in aquaculture systems is a key factor to perform optimal production. Here, we analysed five growth sigmoidal models based on density of previous and current models described in literature (Gompertz, Bertalanffy, Potential and Pütter). These models were fitted to data of Pacific white shrimp cultured in freshwater, with 90, 130, 180, 230, 280 and 330 shrimp/m2 as initial stocking density of culture. Goodness of fit and statistic validation of the density‐dependent model modified from Gompertz proved to display the growth curve that best‐described data of shrimp grown between 90 and 180 densities, whereas the growth model modified from Potential proved to best describe higher stocking densities (230–330). The population dynamics was also modelled using a density‐dependent function. The implications of modelling and their importance in the management of fisheries are discussed. [ABSTRACT FROM AUTHOR]

The physicochemical, biochemical, and microbial stabilities of liquid smoked shrimp during refrigerated (4 ± 1°C) and frozen (−18 ± 1°C) storage for up to 60 days were investigated. During storage, the refrigerated smoked shrimp showed significantly lower values (p <.05) for moisture, water activity, and color coordinates compared to frozen. However, the water holding capacity, cohesiveness, hardness, thiobarbituric acid reactive substances (TBARS), total volatile basic nitrogen (TVB‐N), and pH were higher (p <.05) for refrigerated smoked shrimp compared to frozen. The microbial quality of both refrigerated and frozen shrimps was within quality and safety standards. Smoked shrimp had adequate physicochemical, biochemical, and microbiological characteristics during 60 days of frozen storage and 15 days of refrigerated storage. Novelty impact statement: Shrimps have excellent sensory acceptance and good nutritional aspects. Nevertheless, it presents rapid deterioration due to its high water and enzymatic activities. Thus, conservation techniques are needed to improve shelf life. Liquid smoking has been increasingly used as it improves taste (wide variety of smokes) and preservation and provides low environmental impact. In addition, it allows the deposition of antioxidant and antimicrobial substances and decreases the deposition of carcinogenic compounds such as hydrocarbons and benzopyrenes. However, to be used commercially, it is necessary to know the stability of liquid smoked shrimp during storage under freezing or refrigeration temperatures. [ABSTRACT FROM AUTHOR]

Providencia rettgeri has been recognized as a zoonotic pathogen of humans and aquaculture animals and has become a global public health concern. However, scarce information is available on the characterization of pathogenic P. rettgeri from kuruma shrimp Marsupenaeus japonicus. In the present study, a P. rettgeri isolate (KM4) was confirmed as a causative agent of red leg disease in cultured M. japonicus, which showed a median lethal dose (LD50) value of 5.01 × 105 CFU·ml−1 and had multiple resistances to aminoglycosides, sulfonamides, and tetracycline antimicrobials used in aquaculture. In addition, the whole genome of isolate KM4 was sequenced and found to consist of a single circular chromosome of 4,378,712 bp and a circular plasmid of 171,394 bp. The genome sequence analysis further revealed the presence of potential virulence and antibiotic resistance genes in isolate KM4, which probably rendered this isolate particularly virulent. To our knowledge, this is the first study to characterize P. rettgeri pathogens from kuruma shrimp infected with red leg disease. The findings of this study can provide novel insights into the presence and distribution of pathogenicity‐associated genes in shrimp‐pathogenic P. rettgeri. [ABSTRACT FROM AUTHOR]

The Chinese grass shrimp (Palaemonetes sinensis) was found with a white turbidity appearance in the Panjin area. After dissection, typical symptoms of milky disease with hemolymph emulsification and noncoagulation were observed; however, the pathogen was unknown. In this study, we aimed to isolate the pathogen of the diseased P. sinensis. We found that the pathogen could grow on the fungal medium Bengal red, and microscopic examination showed that it reproduced by budding. Molecular identification of the isolated and purified yeast strain LNMB2021 based on 26S rDNA sequence showed that the pathogenic pathogen was Metschnikowia bicuspidata (GenBank OK094821), with 98.74% homology with M. bicuspidata strain LNES0119 (GenBank OK073903) and 98.56% with M. bicuspidata strain Liao (GenBank MT856369). The results of an artificial infection test showed that M. bicuspidata caused the same clinical symptoms in P. sinensis, and the isolated pathogen was still the same, which proved that P. sinensis was a new host of M. bicuspidata. Histopathological analysis showed that there were obvious pathological changes in the hepatopancreas and muscle tissue of the diseased P. sinensis. Identification of the pathogen is essential for the prevention and control of the disease and the healthy culture of P. sinensis. Furthermore, considering the transmissibility and cross‐host transmission of M. bicuspidata, its risk of infecting other aquatic animals deserves high attention. [ABSTRACT FROM AUTHOR]

The giant freshwater prawn Macrobrachium rosenbergii hatchery operators often face difficulties in seawater transportation. Thus, we aimed to test the locally available crude salt as a suitable alternative to seawater in hatchery operations. For this purpose, seven treatments with different combinations of seawater, brine and crude salt (viz. T1 = 100% seawater, T2 = 100% brine solution, T3 = 100% crude salt, T4 = 80% seawater and 20% crude salt, T5 = 70% seawater and 30% crude salt, T6 = 60% seawater and 40% crude salt and T7 = 50% seawater and 50% crude salt) were tested in the rearing of M. rosenbergii larvae. Water quality parameters exhibited no significant differences, but elemental (Na, Mg, Ca, K, Zn, Cu, Cd and Pb) assemblage (via main effect PERMANOVA) varied across the treatments. Most of the water elements revealed a significant bivariate relationship with the post larvae (PL) production parameters, and this was also confirmed by multivariate RELATE analysis. Among the elements, BEST analysis and the DISTLM model showed that ionic imbalance, especially Na+ concentration, is the main modulator in the hatchery production cycle, productivity and PL survivability. This proves that seawater is the best culture media for larvae rearing but up to 30% replacement by crude salt could be possible at 12 g/L water salinity for giant freshwater prawn PL production. [ABSTRACT FROM AUTHOR]

This study aimed to examine the zootechnical performance, whole‐body composition, activity of digestive enzymes and histology of hepatopancreas of Macrobrachium rosenbergii fed diets incorporated with essential oil from Lippia alba (EOLA) in low (LSD ‐ 50 prawns m−2) and high (HSD ‐ 100 prawns m−2) stocking density. Three diets were formulated; each containing increasing levels of EOLA (0.00 [control], 0.5 and 1.0%) in triplicate for 70 days. Water quality, survival and growth did not differ between treatments. Crude protein was higher in prawns that received 0.5% EOLA in HSD than in LSD. The ethereal extract was higher in prawns in LSD than in HSD fed with EOLA. In addition, the ethereal extract was higher in animals fed diets with 1.0 than 0.0% EOLA in LSD. Prawns that received 0.0 and 1.0% EOLA, respectively, had significantly higher chymotrypsin and alkaline protease activity. In general, the activity of digestive enzymes increased in prawns fed with EOLA in HSD. Histological analyses of the hepatopancreas in all treatments proved to be healthy. In conclusion, the digestive enzymatic activity and crude protein were higher in HSD than in LSD, indicating that EOLA added to the diet is more critical for prawns reared in HSD. In addition, the intensive production of M. rosenbergii can be optimized in HSD (100 prawns m−2) with 1.0% EOLA in the diet. [ABSTRACT FROM AUTHOR]

The expression stability of four potential reference genes (EF1‐α, β‐actin, GAPDH and SubF0) was evaluated to normalize the expression of six immune‐related genes (proPO1, proPO2, MnSOD, PAP, Rab7 and NOS) in different tissues of black tiger shrimp (Penaeus monodon) following melanin injection and using the geNorm and NormFinder algorithms. The stability rankings of the reference genes were as follows: EF1‐α > β‐actin > SubF0 > GAPDH in the muscle, GAPDH > EF1‐α > SubF0 > β‐actin in the carapace and EF1‐α > GAPDH > β‐actin > SubF0 in the haemolymph. To normalize the expression of six immune‐related genes of P. monodon in different tissues under the effect of melanin injection, EF1‐α and GAPDH alone were the most suitable reference genes for the muscle and carapace, respectively, whereas the combination of EF1‐α + β‐actin was the most suitable for the haemolymph. The expression of these six immune‐related genes in P. monodon was upregulated in the haemolymph, downregulated in the carapace and nearly unchanged in the muscle of the melanin‐injected group compared to that in the control group. Our results provide reference genes for reverse transcription quantitative polymerase chain reaction to analyse the protective effects of melanin in black tiger shrimp. [ABSTRACT FROM AUTHOR]

The present study aimed to determine and optimize the drying conditions of shrimp under a hot air‐assisted continuous infrared dryer. Three different levels of infrared radiation (IR) intensity (1,000, 2,000, and 3,000 W/m2), three drying air temperatures (ATs; 55, 65, and 75°C), IR heat source–sample distance (5, 10, and 15 cm), and air velocity of 1.5 m/s were investigated on drying time, specific energy consumption and effective moisture diffusivity of shrimp during drying. Box–Behnken design was used for the optimization of the drying process. Statistical analysis revealed that all the process factors significantly (p <.05) affected the response variables. The optimum values of IR intensity, AT, and IR heat source–sample distance for shrimp drying were observed to be 2,300 W/m2, 55°C, and 10 cm, respectively, at the desirable value of 0.983. The total drying time of 1.9 hr, drying efficiency of 28.39 ± 0.49%, water activity of 0.53 ± 0.01%, rehydration ratio of 2.43 ± 0.03%, total color change value of 17.81 ± 0.82%, and shrinkage ratio of 22.86 ± 0.75% were observed for shrimp drying under optimum conditions. This study revealed that the developed dryer is highly suitable to produce good quality shrimp with substantial energy savings. Practical applications: In the past few years, infrared radiation (IR) drying has gained larger acceptance compared to other conventional drying systems due to its fast drying rate behavior, less energy consumption, and superior product quality. The IR drying conditions of shrimp were optimized based on drying time, specific energy consumption, and effective moisture diffusivity using response surface methodology in this study. A shorter drying time and superior quality characteristics were found in IR drying than convective hot air‐drying systems. The findings revealed that the IR drying process could be suggested for the drying of shrimp compared to other conventional drying techniques. [ABSTRACT FROM AUTHOR]

Ammonia nitrogen is an important source of water pollution that severely limits the development of aquaculture. Macrobrachium nipponense is widely cultivated due to its delicious meat, strong reproductive ability and short reproductive cycle, but the problems caused by germplasm degradation are becoming increasingly concerning. Hybridization is an efficient means to solve this problem. In this study, the parental population, Dianshan Lake (DS) and the hybrid population, DS ♀ × CD (Changjiang, CJ ♂ × Dongting, DT ♀ [SCD]) were exposed to 0, 1 or 10 mg/L total ammonia nitrogen (TAN) for 28 days. Our results indicated that the number of gill‐positive cells and the apoptosis rate of the two groups showed an upward trend with the ammonia nitrogen concentration increased. The ammonia metabolism‐related substance levels and the detoxifying enzyme activities in the gills of shrimp in the SCD group exposed to 10 mg/L of TAN were significantly higher than shrimp in the DS group (p < 0.05). As the TAN concentration increased, the respiratory‐related genes displayed a downward trend and the nitrogen metabolism‐related genes presented an upward trend. Our results suggest that the SCD population had a stronger detoxifying capacity and a greater stress resistance ability than the DS population when subjected to the same concentration of ammonia nitrogen stress. [ABSTRACT FROM AUTHOR]

Precise feeding in the recirculating aquaculture mode is a critical scientific problem that urgently needs a solution. This study aimed to develop an intelligent feeding technique in a recirculating aquaculture system for rearing Litopenaeus vannamei. The core of the intelligent feeding technique is the shrimp biomass prediction model. Accurate prediction of shrimp biomass could determine the appropriate feeding amount and ensure stable water quality. The data‐driven prediction model was developed based on water quality indicators and aquaculture management data collected during shrimp rearing. Multiple linear regression, artificial neural networks and a support vector machine (SVM) were introduced to develop the shrimp biomass predicting model. Results showed that the SVM model gave the lowest root mean square error (0.6500), mean absolute error (0.4368) and mean absolute percentage error (3.70%), as well as the highest accuracy (90.91%). By analysing the predictive ability of the machine learning models, it was determined that the SVM model was the optimal model for predicting biomass. The intelligent feeding machine can apply the optimal model to calculate the shrimp biomass and determine the appropriate feeding amount by reading the sensors in real time. [ABSTRACT FROM AUTHOR]

In this study, a risk assessment on Vibrio parahaemolyticus infections was carried out in order to estimate the likelihood of gastroenteritis for Cameroonians after consumption of roasted shrimp (Penaeus monodon). The Codex Alimentarius Commission framework was used in this study. Based on the distribution of total V. parahaemolyticus in shrimp and literature information indicating that nonhaemolysing carrier strains could be pathogenic to humans, the cooking, and consumption patterns, the daily exposure level generated in this study, and the dose-response model from other studies, the infectious risk was evaluated and quantified by the Monte Carlo simulation. This simulation was realized based on 10,000 iterations using the Model Risk software, version 4.0, in combination with Microsoft Excel. To better quantify the exposure of consumers and the resulting risk of infection, several scenarios reflecting the minimal, average, and maximal exposures were undertaken. According to the results, the 90% confidence intervals for minimum and maximum exposures ranged from 15 to 24 colony-forming units per day (cells/day) and from 160 to 228 cells/day, respectively. Based on the modal scenario, 90% of the population consuming this shrimp is exposed to V. parahaemolyticus loads ranging from 74 to 110 cells/day, indicating a risk of infection ranging from 1.2 to 1.8 cases per million of consumption. The estimated number of annual disease cases based on annual production is between 1 and 10 cases. This reflects a relatively low risk of infection for roasted shrimp. Good hygiene practices during handling, cooking, and storage may help reduce the actual risk. [ABSTRACT FROM AUTHOR]

This study aimed at evaluating the effect of natural astaxanthin extracted from shrimp shells on the growth and skin pigmentation of the Orange clownfish, Amphiprion percula. Astaxanthin diets (with serial concentrations of 0–150 mg kg−1 feed) supplemented to the Orange clownfish were set up to improve their performance. Our data revealed that the astaxanthin feed did significantly affect the Orange clownfish skin pigmentation. After 8 weeks on the 75–150 μg g−1 concentration astaxanthin diet, the high redness (a*) value was measured at 14.40–14.95 (Minolta, CR400), while the control group had an a* value of 10.53 ± 0.26 (p < 0.05). The highest carotenoid level was also determined in fish skin (UV–vis spectrophotometer) of 44.20 ± 2.12 μg g−1 tissues at the carotenoid concentration of 150 μg g−1. The higher values of the growth of this specie were also observed in the groups with feed added astaxanthin compared with the control group. Our findings suggest that natural astaxanthin from shrimp shells could be applied in the field of aquaculture to improve the skin pigmentation and growth of the Orange clownfish. [ABSTRACT FROM AUTHOR]

The prawns fed with Lactococcus lactis obtained 100% survival in the BFT and BFTPROB treatments compared to the CONT (80%). Regarding growth, it was observed in PROB and BFTPROB treatments, the organisms got greater weight (6.3 ± 1.6, 6.8 ± 1.3 respectively) compared to the other treatments. The effect of L. lactis in the bacterial community of Macrobrachium rosenbergii postlarvae (PL's) with initial mean weight of 0.1 g, and length 1.4 cm in biofloc, was evaluated. A randomized experimental design was used: T1:BFT: biofloc; T2:BFTPROB:biofloc+probiotic; T3:PROB:probiotic; T4:CONT:control; all in triplicate with 60 PL's/treatment. On days 64 and 127, the weight and length of prawns were determined. 15 guts/treatment were extracted and water samples to obtain bacterial DNA. Massive sequencing of 16S rRNA gene of the samples was performed. Metagenomic analysis identified 17 bacteria classes in gut and water samples. The most abundant were Alphaproteobacteria, Gammaproteobacteria, Betaproteobacteria, Flavobacteria, Actinobacteria, and Clostridia with different benefits in the prawns' health. The bacterial community in the intermediate phase was different to the final, maybe for the colonization capacity of certain bacteria that developed in each treatment. However, L. lactis did not affect the microbial community in prawns' gut and culture water, it attributed to the displacement of the microbial community in biofloc and other probiotics, however it was observed a better prawns' growth and survival with biofloc and probiotic treatments. [ABSTRACT FROM AUTHOR]

Shrimp is the white gold of Bangladesh, with the second-highest income source from exporting to foreign countries. Contamination with Salmonella spp. is now one of the significant issues for Bangladesh to export. Proper characterization of the salmonella pathogen is thus necessary to avoid undesirable losses due to the rejection of exported shrimp. In Bangladesh, the present condition of raw shrimp contamination with pathogenic Salmonella serovars and their survival/virulence properties was not adequately characterized. In this study, we collected 43 raw shrimps as samples from different farms in Jashore, Khulna, and Sathkhira regions. We then maintained standard cultural and biochemical protocols for isolating Salmonella strains, followed by the molecular identification of particular Salmonella serovars. The standard method for checking its credibility to form biofilm in 0–10% NaCl, tolerate acid/bile stress likewise in the gastrointestinal tract, and resist antimicrobial pressure was performed individually with the particular pathogenic strains. Our results successfully identified eleven Salmonella strains with three typhimurium serovars and three enteritidis serovars, which have biofilm-forming capability up to 4–8% NaCl, acid/bile habituation alike stomach/small intestine of humans, and resistance against necessary antibiotics generally used in treating human and poultry infection signifying the impending danger in the shrimp industry. While previous studies of Bangladesh successfully isolated Salmonella only presumptively, our research focused mainly on molecular characterization of the human Salmonella pathogen along with important survival and virulent attributes, such as biofilm formation, acid/bile tolerance, and antibiotic resistance of selected S. typhimurium and S. enteritidis strains. Further study with more sampling will be necessary to confer the transmission route of the pathogen from the natural reservoir to the shrimp industry. [ABSTRACT FROM AUTHOR]

Shape morph-specific studies in hippolytid shrimps revealed significant results on their ecomorphology and evolutionary adaptations. Among the species of the genus Hippolyte, only one exhibits an unusual, sharp rostral dimorphism and has been used as an animal model for the investigation of mechanisms of the morph-specific adaptation: the intertidal Hippolyte sapphica. The species is endemic of the Central/Eastern Mediterranean basin and exhibits morph-A with a long dentate rostrum and morph-B with a short, juvenile-like one. The two morphotypes were recently confirmed to be conspecific, while offspring and morphological studies showed significant microevolutionary adaptations, which balance the disadvantage of the "rostral loss." The present study aims to investigate the effect of such phenotypic variation on the reproductive traits of the species. We collected ovigerous females of H. sapphica in mixed (morph-A and morph-B) and unmixed populations (morph-A) along the species geographical range. We measured seven morphometric and maternal investment traits: carapace length, fecundity, embryo volume, egg density, female dry weight, brood dry weight, and reproductive output. Our results showed that ovigerous females were bigger in morph-A than in morph-B, whereas fecundity did not show any significant differences between the two morphotypes. High egg volume might be attributed to the latitudinal differences of our sampling sites compared to congenerics. Interestingly, the reproductive output was found to be bigger in morph-A specimens, suggesting that the maternal energy investment is selectively determined from the rostral presence/absence and the morphotype's higher viability in the species populations. [ABSTRACT FROM AUTHOR]

Head of Litopenaeus vannamei, a low‐priced by‐product, was used to make fermented shrimp paste, Kapi, instead of the traditional raw material. The addition of garlic was hypothesized to prevent oxidation of unsaturated fatty acids, and tested by using garlic at 0%, 3%, and 5%. Decreasing aw was found in all treatments, while pH seemed to not change during fermentation. TVB‐N, TMA, malondialdehyde, and DH significantly increased with fermentation time. The addition of garlic at 3% and 5% seemed to retard lipid oxidation compared to the control case. After fermentation for 90 days, significant indole was noticed but no histamine was detected, while TVC and LAB of all treatments decreased. However, no pathogenic microorganisms were found. Likeness scores of all cases were approximately 6/9. Shrimp head can be used as an alternative raw material for making Kapi, but the texture and taste attributes must be improved in future work to meet consumer preferences. Novelty impact statement: Shrimp head can be a substituted raw material to produce shrimp paste. Shrimp head paste with 12:1 ratio of shrimp head to salt and added with garlic at 3% can retard lipid oxidation in the product. Shrimp head waste is brightening for the prevention of authentic Thai dishes collapse due to shortening of shrimp paste. [ABSTRACT FROM AUTHOR]