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The trans-molting retentive external eye (TRAMORE) tag is inexpensive, easy to apply, and immediately detectable without specialized detection devices. Its conspicuousness ensures almost no risk of consumption by humans, and it does not affect the survival and growth of Penaeus japonicus juveniles under experimental conditions without predation risks. However, during predator escape, the TRAMORE tag may become an obstacle during submerging into sand and/or swimming. Similar to traditional marking methods such as uropod ablation for identifying released individuals, little is known about whether TRAMORE tagging increases predation risk. If it does, the effectiveness of stock enhancement programs might be underestimated. This study aimed to determine whether TRAMORE tagging and uropod ablation marking influence the predator avoidance of P. japonicus juveniles through laboratory experiments. The time required to submerge into sand was not significantly affected by TRAMORE tagging nor uropod ablation marking. Neither TRAMORE tagging nor uropod ablation marking significantly affected the angle and distance of escape jumps. However, uropod ablation marking significantly slowed escape speed. These results indicate that the newly developed TRAMORE tag is more suitable for identifying released P. japonicus juveniles than the traditional uropod ablation marking method. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effects of dietary lipid sources on the survival, growth, nutritional quality and sensory quality of Penaeus japonicus. Three feeds with equal nitrogen (40.31%) and equal lipid (9.35%) were prepared by including equal amounts of fish oil, soybean oil or flax oil, respectively. The experiment was carried out in the floating sea water cages, and each cage was stocked with 25 individuals of P. japonicus [initial body weight: (5.82±0.02) g]. The feeding experiment was lasting for 60 days. The results showed that: ① the survival rate of the fish oil group was significantly higher than that of the soybean oil group and the flaxseed oil group (P<0.05). The specific growth rate and weight gain rate of the flaxseed oil group were significantly higher than those of the fish oil group and the soybean oil group (P<0.05). ② The sensory quality of shrimp in the flaxseed oil group was significantly higher than that in the fish oil group and soybean oil group (P<0.05), but the color difference of the soybean oil group was closer to that of the standard color. ③ P. japonicus in the fish oil group showed significantly higher contents of total amino acids (ΣTAA), total essential amino acids (ΣEAA), total non-essential amino acids (ΣNEAA) and sweet amino acids than those in the soybean oil group and the flaxseed oil group (P<0.05). The contents of bitter amino acids in the soybean oil group were significantly higher than those in the fish oil group and flaxseed oil group (P<0.05). There was no significant difference in the umami amino acids of muscle among dietary groups (P>0.05). ④ P. japonicus in the fish oil group began to spoil on the sixth day, and the soybean oil group and flax oil group began to spoil on the second day, by using the TVB-N (total volatile basic nitrogen) value as the shelf life parameter of aquatic products. [ABSTRACT FROM AUTHOR]

[Display omitted] Notwithstanding the progress made, cargo molecules encapsulated within ferritin via oral administration in the gastric environment remains a persistent challenge. This study focuses on the strategic enhancement of ferritin stability in harsh gastric environment. By taking advantagie of computational-assisted design, we strategically introduced up to 96 disulfide bonds along three key inter-subunit interfaces to one single ferritin molecule with human H-chain ferritin and shrimp (Marsupenaeus japonicus) ferritin as starting materials, producing two kinds of robust ferritin nanocages with markedly enhanced acid and protease (pepsin and rennin) resistance. The crystal structure of ferritin nanocage confirmed our design at an atomic level. Encapsulation experiments demonstrated successful loading of bioactive cargo molecules (e.g., doxorubicin) into the engineered ferritin nanocages, with pronouncedly improved protection against leakage under acidic condition and the presence of pepsin and rennin as compared to their native counterparts. This study presents a potential approach for the design and engineering of protein nanocages for oral administration. [ABSTRACT FROM AUTHOR]

Integration of biological activities of the algal and bacterial communities enhances the bioremediation potency of aquaculture systems. The effects of nitrogen removal mediated by Ulva lactuca on the bacterial community structure and the abundance of nitrogen cycle functional genes were investigated using an integrated multi-trophic aquaculture (IMTA) system mainly composed of sea cucumber (Stichopus japonicus), shrimp (Penaeus japonicus), and crab (Portunus trituberculatus). The experimental treatments were separated into two groups: control group (C: without U. lactuca) and algae treatment (A: with U. lactuca). Microbial diversity and abundance indexes, including the Sobs, Shannon, Ace, and Chao1 indexes, were higher in the U. lactuca treatment group in both water and sediment. Flavobacteriaceae and Rhodobacteraceae were the dominant families in both the U. lactuca and control treatment groups in October and November, respectively. In sediment, Bacillaceae was the dominant family in the U. lactuca treatment group throughout the experimental period, whereas Desulfocapsaceae was the dominant family in the control group in October and November. Moreover, the nitrogen cycle functional genes nifH, amoA, nxrB, norB, and nrfA were more abundant in the U. lactuca treatment group than in the control group. Results of water quality and its correlation with bacterial community were comprehensively investigated, revealing that U. lactuca influenced the bacterial community structure and nitrogen cycle by increasing DO in the IMTA system. In conclusion, U. lactuca co-cultured in an IMTA system could represent a novel approach for enhancing nitrogen removal, based on the interaction between the algal and bacterial communities. [ABSTRACT FROM AUTHOR]

To popularize Kuruma shrimp, Penaeus (Marsupenaeus) japonicus Form II, as a part of the diversification of shrimp farming across India, seed production and growth performance studies were conducted. In experiment I, the reproductive performance of Kuruma shrimp was studied in captive system. In experiment II, a 75-day growth performance study was carried out in 2 × 2 factorial design with and without sandy bottom (S) as the first factor and outdoor units having natural light (O) and indoor units with restricted light (I) as the second factor resulting in four treatments: O+S, O-S, I+S and I-S. The seed production trial recorded an average survival of nauplius to post larvae (PL) 36 ± 12%. In experiment II, the PL (0.02 ± 0.01 g) was stocked at 300 PL m−3 to study the effect of sandy bottom and light intensity on growth performance. Results indicated that the highest final body weight (0.63 ± 0.05 g) and survival (80 ± 2.0 %) were registered in outdoor units without (O-S) and with sandy bottom (O+S), respectively. Although no difference (p > 0.05) in body weights were recorded among the treatments, the Kuruma shrimps reared under indoor units with restricted light intensity had lower (p < 0.05) survival (43–45%). The light intensity varied from 459 to 6583 lux in the outdoor system whereas indoor units had only 8–35 lux. A significant interaction effect (p < 0.01) between the sandy bottom and light intensity on food conversion ratio (FCR), coefficient of variation at final weight, CVabw (%), nitrite-N, TSS and chl–a level were noticed. The Kuruma shrimp reared under outdoor units (O+S and O+S) had well-developed chromatophores; meanwhile, the transparent colouration was recorded in the shrimps reared under restricted light intensity. The present study concludes the potential to rear P. japonicus Form II in tank or lined rearing system without the sandy bottom and scope to develop location-specific culture and seed production techniques. [ABSTRACT FROM AUTHOR]

Our study aims to investigate whether Macleaya cordata extracts (MCE) could alleviate the adverse reactions caused by a high-fat (HF) diet in Marsupenaeus japonicus. Three experimental treatments including a control group (CG, 8.06% lipid), HF group (14.76% lipid), and HF group supplemented with 1200 mg/kg Macleaya cordata extract (HFG + MCE) were designed. The results showed that growth performance was not influenced (P > 0.05) by different diet treatments after a 42-day feeding trial. Compared with the control group, the HF group significantly decreased (P < 0.05) the activities of antioxidant enzymes in the serum and hepatopancreas. Expression of antioxidant-related genes was synchronously decreased (P < 0.05), while hsp70 gene expression was increased (P < 0.05) in the hepatopancreas. Hepatopancreatic glycolipid metabolism was upregulated (P < 0.05), which could be identified by lipid/glycogen content and gene expression. Compared with the HC group, the HC + MCE group significantly alleviated HC-induced oxidative stress, which was identified by the increased (P < 0.05) antioxidant enzyme activities and gene expression. Meanwhile, hepatopancreatic glycolipid metabolism was downregulated (P < 0.05). In conclusion, dietary supplementation with MCE could alleviate HF-induced damage of antioxidant capacity and immune function and alleviate the disorder of glycolipid metabolism in M. japonicus. [ABSTRACT FROM AUTHOR]

Data on catch and effort for 39 fishing seasons of the Large-Shrimp category were collected from the General Authority for Fisheries Resource Development, Suez Office (GAFRD). Fishery of Large-Shrimp in the Gulf of Suez suffers from severe growth and recruitment overfishing. The catch maximum sustainable yield (CMSY++) method was applied to estimate the biological reference points for scientific rebuilding and management of Large-Shrimp fishery in the Gulf of Suez. The catchability coefficient of the commercial bottom trawl net is high (q = 9.62). The intrinsic increase rate of the fishery is relatively high, (r = 0.28 y−1). In the healthy state, values of the carrying capacity (K), maximum sustainable yield (MSY), and fishing mortality for MSY (FMSY) are 6050 tons, 429 tons, and 0.141 y−1 respectively. Consequently, it is suggested that the fishery of Large-Shrimp may be rebuilt in three seasons if exploitation is stopped. There is thus a good opportunity for a safe wide range of management strategy alternatives while avoiding bad effects for fishermen.

Simple Summary: The individual-rearing method has proven beneficial for detailed studies on the growth and feeding of aquatic organisms, helping to minimize the impact of non-dietary factors such as cannibalism. The Kuruma shrimp Penaeus japonicus occupies a significant niche in global aquaculture, but there is still a gap in the research on its nutrient supply, particularly in comparing the nutritional impacts of live feed and pellet diets. This study employed an individual-rearing method to investigate the effects of live feed (Perinereis aibuhitensis), formulated pellet diets, and their combinations on the growth and health of P. japonicus. The results revealed that live feed can enhance shrimp growth performance compared to pellet diets and provide a healthier and more stable intestinal flora. Growth and feeding performance on a mixed diet were comparable to live feed while also reducing costs. And the individual-rearing method allowed us to find inter-individual differences in growth and feeding, with daily intake varying cyclically with the molting cycle. These findings elucidate the feed preferences as well as the growth and feeding characteristics of shrimp, offering novel methodologies for shrimp feed selection, trait collection, and breeding strategies. This has the potential to significantly enhance aquacultural practices. This study developed an individual-rearing method to compare the effects of live feed (sandworms Perinereis aibuhitensis), formulated pellet diets, and a mixture of live feed and formula feed on the Kuruma shrimp Penaeus japonicus, aiming to minimize the influence of non-dietary factors on the growth of P. japonicus, like cannibalism. Results indicated that live feed, with its higher protein, essential amino acids, and fatty acid content, led to significantly better growth and feeding performance in P. japonicus (p < 0.05) compared to pellet diets. A mixed diet resulted in a lower average daily protein intake yet maintained a growth and feeding performance comparable to live feed. The intestinal microbiota of shrimp, dominated by Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria, showed significant shifts with diet changes. Specifically, formulated feed increased the relative abundance of Vibrio and Photobacterium while decreasing Shimia and Rhodobacterales (p < 0.05), and feeding live food resulted in a more complex and stable bacterial network. Notably, individual variances in growth and feeding were observed among shrimps, with some on formulated diets showing growth comparable to those on live feed. Each shrimp's final weight, specific growth rate, protein efficiency rate, and average daily food intake positively correlated with its initial body weight (p < 0.05), and daily intake varied cyclically with the molting cycle. These findings suggest that individual-rearing is an effective approach for detailed feed evaluation and monitoring in P. japonicus, contributing to improved feed selection, development, and feeding strategies. [ABSTRACT FROM AUTHOR]

D-Glutamate, a novel d -amino acid found in animal tissues, exclusively exists in the male reproductive tissues of the kuruma prawn, Marsupenaeus japonicus. Herein, changes in the d -glutamate content were determined in the male reproductive tissues of M. japonicus during acclimation to breeding seawater temperatures of 18–22°C and unilateral eyestalk ablation. The d -glutamate content in the testis increased with increasing seawater temperature and with unilateral eyestalk ablation. This suggests that both stimulations induced d -glutamate synthesis in the testis. Although the d -alanine content in the testis increased after unilateral eyestalk ablation, it did not change with elevated seawater temperature. Furthermore, we determined the d -glutamate distribution in the M. japonicus spermatophore. This indicates that d -glutamate is crucial in prawn fertilization. [ABSTRACT FROM AUTHOR]

The cellular endosomal sorting complex required for transport (ESCRT) system comprises five distinct components and is involved in many different physiological processes. Recent studies have shown that different viruses rely upon the host ESCRT system for viral infection. However, whether this system is involved in white spot syndrome virus (WSSV) infection remains unclear. Here, we identified 24 homologs of ESCRT subunits in kuruma shrimp, Marsupenaeus japonicus, and found that some key components were strongly upregulated in shrimp after WSSV infection. Knockdown of key components of the ESCRT system using RNA interference inhibited virus replication, suggesting that the ESCRT system is beneficial for WSSV infection. We further focused on TSG101, a crucial member of the ESCRT-I family that plays a central role in recognizing cargo and activating the ESCRT-II and ESCRT-III complexes. TSG101 colocalized with WSSV in hemocytes. The addition of N16 (a TSG101 inhibitor) markedly decreased WSSV replication. TSG101 and ALIX of the ESCRT system interact with WSSV envelope proteins. The host proteins TSG101, RAB5, and RAB7, the viral protein VP28, and DNA were detected in endosomes isolated from hemocytes of WSSV-infected shrimp. Knockdown of Rab5 and Rab7 expression reduced viral replication. Taken together, these results suggest that the ESCRT system is hijacked by WSSV for transport through the early to late endosome pathway. Our work identified a novel requirement for the intracellular trafficking and infection of WSSV, and provided novel therapeutic targets for the prevention and control of WSSV in shrimp aquaculture. IMPORTANCE Viruses utilize the ESCRT machinery in a variety of strategies for their replication and infection. This study revealed that the interaction of ESCRT complexes with WSSV envelope proteins plays a crucial role in WSSV infection in shrimp. The ESCRT system is conserved in the shrimp Marsupenaeus japonicus, and 24 homologs of the ESCRT system were identified in the shrimp. WSSV exploits the ESCRT system for transport and propagation via the interaction of envelope proteins with host TSG101 and ALIX in an endosome pathway-dependent manner. Understanding the underlying mechanisms of WSSV infection is important for disease control and breeding in shrimp aquaculture. [ABSTRACT FROM AUTHOR]

The present study was designed to assess the influence of fishmeal replacement with increasing percentages of fresh seafood discards (0, 25, 50 and 75%) in diets for Penaeus japonicus on growth performance, physical characteristics and the chemical and fatty acid composition of shrimp flesh. Each diet was administered for 108 days, and the trial was assayed in triplicate. The final body weight and the specific growth rate were significantly higher (p < 0.05) in shrimps fed with 75% fishmeal replacement as compared to 25%, while the abdomen weight and the total length were the highest (p < 0.01). Moreover, 75% replacement showed a significantly (p < 0.05) lower value of hardness and a greater crude protein and lipid content as compared to the 0% replacement. The shrimps fed with high levels of seafood discards (50 and 75%) showed a lower saturated fatty acid concentration and, in turn, a greater amount of polyunsaturated fatty acids in shrimp meat significantly (p < 0.05) affected the lower atherogenic and thrombogenic indices. In conclusion, replacing 75% of fishmeal with seafood discards provided satisfactory results. An economic analysis based on ESG indicators and PESTLE methodology is provided in order to show the socio-economic and governance impacts affecting the replacement of shrimps' diet with fish discard. [ABSTRACT FROM AUTHOR]

Several crustaceans including shrimps change the amount of specific free amino acids to regulate the osmotic pressure in their bodies. Kuruma shrimp Penaeus japonicus also increases the concentration of alanine (Ala) in the abdominal muscle following the increase of environmental salinity. In the present study, to elucidate the mechanisms of changes in Ala accumulation of kuruma shrimp depending on salinity, we cloned the gene encoding alanine aminotransferase (ALT), an enzyme involved in Ala biosynthesis, and examined its expression profile. It was found that the full‐length kuruma shrimp ALT1 cDNA consisted of 3,301 bp, encoding 514 amino acids, and that all amino acid residues important for ALT activity were conserved. Phylogenetic analysis also indicated that the ALT gene cloned in this study was classified as ALT1. Moreover, we examined the expression levels of the ALT1 gene in the abdominal muscle and the hepatopancreas of kuruma shrimp acclimated at 17‰, 34‰, and 40‰ salinities, resulting that the mRNA levels of the ALT1 genes in both tissues of the shrimp acclimated at 40‰ were significantly higher than those at 17‰ for 12 h (p < 0.05). The mRNA levels of the ALT1 gene in the abdominal muscle of the shrimp acclimated for more than 24 h tended to increase following the increase of environmental salinity. These results indicate that ALT1 is responsible for the increase of free Ala concentration in the abdominal muscle of kuruma shrimp to regulate osmotic pressure at high salinity. [ABSTRACT FROM AUTHOR]

Data on catch and effort for 39 fishing seasons of the Large-Shrimp category were collected from the General Authority for Fisheries Resource Development, Suez Office (GAFRD). Fishery of Large-Shrimp in the Gulf of Suez suffers from severe growth and recruitment overfishing. The catch maximum sustainable yield (CMSY++) method was applied to estimate the biological reference points for scientific rebuilding and management of Large-Shrimp fishery in the Gulf of Suez. The catchability coefficient of the commercial bottom trawl net is high (q = 9.62). The intrinsic increase rate of the fishery is relatively high, (r = 0.28 y−1). In the healthy state, values of the carrying capacity (K), maximum sustainable yield (MSY), and fishing mortality for MSY (F MSY) are 6050 tons, 429 tons, and 0.141 y−1 respectively. Consequently, it is suggested that the fishery of Large-Shrimp may be rebuilt in three seasons if exploitation is stopped. There is thus a good opportunity for a safe wide range of management strategy alternatives while avoiding bad effects for fishermen. [ABSTRACT FROM AUTHOR]

Herein, the link between rearing environmental condition and metabolism was explored. Metabolite fingerprint datasets of black tiger shrimp (Penaeus monodon) from three production sites were collected and studied using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) and HPLC-MS/MS. Two compounds, benzisothiazolinone and hippuric acid, were identified to be potentially related to pollution in the rearing environment and showed different abundances in the analysed shrimp samples with different origins. Furthermore, metabolomic analysis on three shrimp species, black tiger shrimp, kuruma shrimp (Penaeus japonicus) and sword shrimp (Parapenaeopsis hardwickii), under an identical rearing environment was also conducted. Two compounds, diethanolamine and benzisothiazolinone, potentially linked with pollution in the rearing environment were identified. The present protocol holds promise to be extended to the studies of exploring the relationship between rearing environmental conditions and metabolism. Furthermore, the analysis of single-blind samples was conducted. The results show that specific metabolites can be utilized as markers for tracing the origins of shrimp samples. The present protocol holds potential for application in tracing the origin and species of certain seafoods. [ABSTRACT FROM AUTHOR]

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

It is reported that ILF2 (interleukin enhancer binding factor 2) is involved in the immune response by regulating the transcription of interleukin 2 (IL2), which may play an important role in host-virus interactions. To investigate the role of ILF2 in WSSV infection in Penaeus japonicus, the ILF2 gene was characterized by bioinformatics analysis and RNAi. The sequence of 873 bp ORF region encoding 290 amino acids was obtained by PCR amplification in this study. The relative molecular weight of ILF2 protein is 32.29154 KDa. The bioinformatics analysis indicated that the ILF2 protein has an DZF domain and a RGG domain and contained a large number of alpha helices and irregular coils. The results of tissue-specific assays demonstrated that ILF2 was highly expressed in the hemolymph and gill of shrimp. After WSSV stimulation, qRT-PCR analysis showed that the expression of ILF2 was significantly increased in all tissues of shrimp. Using RNAi to knock down the expression of ILF2 in shrimp, the results showed that the copy number of WSSV in shrimp was significantly increased, suggesting that ILF2 could inhibit the replication of WSSV. The results showed that ILF2 had the potential to inhibit WSSV replication and to achieve antiviral properties, providing a theoretical basis for the control of WSSV in shrimp. [ABSTRACT FROM AUTHOR]

In order to study the muscle quality of different crustaceans, we aim to provide a comprehensive assessment of their muscle quality characteristics as a theoretical reference. In this work, seven major species of farmed and consumer crustaceans were selected, including crayfish (Procambarus clarkii), freshwater prawns (Macrobrachium rosenbergii), pacific white shrimp (Litopenaeus vannamei), black tiger shrimp (Penaeus monodon), kuruma prawns (Penaeus japonicus), river prawns (Macrobranchium nipponense), and Chinese shrimp (Penaeus chinensis). Their morphometric parameters, nutritional composition, textural properties, and physical and chemical indexes were comparatively analyzed. The results showed that the meat content (MC, about 14.78%) of crayfish was significantly lower than that of the other six species. By contrast, pacific white shrimp had the highest MC, although the MCs of black tiger shrimp, kuruma prawns, and Chinese shrimp are greater than 40%. All seven crustacean species were high in protein and low in fat, while pacific white shrimp had the highest crude protein, crude lipid, and crude ash content compared to the other crustaceans. The content of threonine (Thr) was the highest in crayfish. The content of methionine (Met) and lysine (Lys) was the highest in freshwater prawns. The content of isoleucine (Ile), leucine (Leu), and non–essential amino acid (NEAA) was the highest in pacific white shrimp. C18:2n-6 (linoleic acid, LA) was the highest in freshwater prawns and pacific white shrimp; C18:3n-3 (linolenic acid, LNA), C20:4n-6 (arachidonic acid, AA), unsaturated fatty acids (UFA), and monounsaturated fatty acids (MUFA) were all the highest in crayfish; and polyunsaturated fatty acids (PUFA) was the highest in freshwater prawns, but the content was not significantly different from crayfish, pacific white shrimp, black tiger shrimp, and Chinese shrimp. Pacific white shrimp had the highest values for hardness, cohesiveness, gumminess, and chewiness. The redness values of crayfish, black tiger shrimp, and Chinese shrimp were significantly higher than those of the other three species except kuruma prawns. Compared to other crustaceans, river prawns had the highest drip loss and cooking loss. Black tiger shrimp and Chinese shrimp had the lowest cooking loss rates. The research shows that the tail muscle of the seven species of crustaceans is rich in protein, essential amino acids, unsaturated fatty acids and low in fat, representing a high-quality protein. Among these crustaceans, the main essential amino acids and essential fatty acids in the tail muscle of pacific white shrimp, freshwater prawns, and crayfish are higher in content and better in nutritional value. [ABSTRACT FROM AUTHOR]

The nutritional quality of fish and shrimp cooked with sous-vide was investigated. Vacuum-packed fish and shrimp were cooked at 70 and 85°C for 15 and 25 minutes. Proximate, free amino acid, and B vitamin compositions were investigated. Higher moisture levels, lower cooking losses, and lower protein content were found in sous-vide cooked samples than conventionally cooked ones. In all cooking treatments of fish, losses in amino acids and vitamins were observed. Fluctuations in amino acid changes were observed in shrimps. All losses were lower in sous-vide cooked samples. In conclusion, sous-vide cooking maintains the nutritional value of fish and shrimp. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the changes in the quality of fish (Argyrosomus regius) and shrimp (Penaeus japonicus) cooked with sous-vide. Vacuum-packed fish fillets and shrimps were cooked with the sous-vide method under different temperature-time conditions and stored at 3 °C. Lower volatile bases and trimethylamine were found with cooking sous-vide than in control samples (cooked in an oven). Microbiological analysis results showed that the sous-vide cooking method provides bacterial inhibition in fish and shrimp. The sensory properties of samples cooked with sous-vide were found to be better than those of the traditional method. Sous-vide cooking did not affect the L* value of fish but affected that of shrimp. Sous-vide cooking resulted in higher a* values and lower hardness, gumminess, and chewiness values. As a result, sous-vide cooking increased the shelf life of fish and shrimp, reduced cooking loss, preserved color and texture, and provided microbial safety. [ABSTRACT FROM AUTHOR]

China’s shrimp farming industry has experienced significant growth in recent years. With such a development, some major constraints linked to the industry’s sustainable development have emerged. This paper aims to present an overview of China’s shrimp industry over the last two decades, with special attention to farm-raised shrimp both in marine and inland waters. Documentary research on its recent evolution was carried out based on data collected from China Fishery Statistics Yearbooks 2003 to 2022 coupled with data from FAO. Findings indicated that there has been an upward trend in China’s total shrimp production over the last 20 years, with a growth rate of 120%, representing an average annual growth rate of 4.3%. The observed higher shrimp production was driven by expanded shrimp aquaculture production, with major species dominated by the Pacific whiteleg shrimp (litopenaeus vannamei), the black tiger shrimp (Penaeus monodon), the Chinese shrimp (Penaeus chinensis), and the Japanese prawn (Penaeus japonicus). Challenges associated with the intensification of the production and the driven environmental deterioration need to be properly addressed. First, the shrimp farming industry should be practiced while considering both environment and ecosystem protection. Applying such an organic farming principle presupposes some practices for addressing the existing issues threatening the sustainable growth of the industry. To that end, there is a need for innovative techniques that should be strengthened. Second, possible solutions to shrimp disease problems, namely prevention, early diagnosis, and various control techniques, should also be developed and improved, with an emphasis on the former. In addition, encouraging the use of good-quality feed in appropriate quantity and form is also of paramount importance. It is thus worth noting that further policies need to focus on promoting a large range of ecological shrimp aquaculture technologies that should be encouraged among farmers. [ABSTRACT FROM AUTHOR]

The relationship between water quality and bacterial composition may determine the sustainability level in an integrated multi-trophic aquaculture (IMTA) system. In this study, the effects of different shrimp stocking densities on water quality and bacterial community structure were studied in a sea cucumber-shrimp-crab-fish IMTA system. The results showed correlations between bacterial community structure and water quality parameters (dissolved oxygen, salinity, pH, ammonia nitrogen, nitrite nitrogen, and phosphate phosphorus) under different stocking densities of Penaeus japonicus. Temperature, salinity, nitrite nitrogen, ammonia nitrogen, and phosphate phosphorus were significant factors (p < 0.05) influencing the bacterial community in the samples. Nitrite nitrogen showed the greatest effect on bacterial community diversity and richness. Flavobacteriaceae and Cryomorphaceae play important roles in the denitrification process, and these bacteria were significantly more abundant in low-density ponds than in high-density ponds. This study provides practical knowledge on shrimp stocking density management and its effect on IMTA system biosecurity. [ABSTRACT FROM AUTHOR]

Some aquatic invertebrates contain free d -alanine. We previously showed copious amounts of free d -glutamate, a novel d -amino acid, in the tissue of the male reproductive organs of Marsupenaeus japonicus. Herein, we clarified the distribution and potential role of d -glutamate and d -alanine in male reproductive tissues, namely the testis, vas deferens and seminal receptacle at different growth stages of M. japonicus. The percentage of d -glutamate to total glutamate was over 50% in these tissues. In particular, the content of d -glutamate was the most abundant in the vas deferens, the ratio of d -glutamate to total glutamate was approximately 80%. In contrast, d -alanine content was the lowest in the vas deferens among these tissues. d -Glutamate content was the highest when the prawn weighed 12 g, indicating that d -glutamate is actively synthesized in the younger stage. Our findings suggest that d -glutamate plays an important role in the reproductive functions of M. japonicus. [ABSTRACT FROM AUTHOR]

Regulation of microRNAs (miRNAs) on various biological processes has been a surprising and exciting field. Identification of miRNAs is the first step to comprehensively understand their functions. However, attempts on global identification and functional verification of miRNAs are very limited in penaeid shrimp Marsupenaeus japonicus, an economically important aquatic species. By performing an integrated analysis of transcriptomic profile from gastrula embryos of M. japonicus, 21 conserved miRNAs in M. japonicas (mja-miRNAs), belonging to 19 miRNA families, were identified and characterized. Of the 21 mja-miRNAs, 15 miRNAs were successfully verified to be predominantly expressed in gastrula stage, where they displayed dynamic expression patterns compared with those in naupliuin stage. Based on perfect or near-perfect match to target region, 120 target genes were predicted at transcriptome-wide level. Noteworthy, gene ontology (GO) classification and metabolic pathway annotation revealed eight targets that were actively involved in developmental processes. Of the predicted miRNA-mRNA pairs, six targets were then randomly selected and experimentally validated by dual luciferase reporter assay, where three pairs were proved with potential targeting activity. Overall, to search for conserved miRNAs potentially involved in early development of M. japonicus, we combined in silico and experimental methods, which can be applied in other organisms as well. Our data implied important roles of miRNAs in the early embryonic development and also suggested the presence of complex miRNA-mRNA functional networks in M. japonicus. [ABSTRACT FROM AUTHOR]

This research applies an oxygen level monitoring system in tiger prawn ponds using a Dissolved Oxygen (DO) sensor based on Wemos D1 R1 with an Internet of Things (IoT) approach. Tiger prawn ponds, as cultivation centers, require regular monitoring of water quality. This system uses a DO sensor in water, processed by Wemos D1 R1, and the data is sent to Firebase Cloud for storage. The web application serves as a user interface for monitoring and analyzing data. The results of research at the Pandawa 1000 tiger prawn pond, Lanrisang Village, Pinrang, show the positive impact of IoT technology on pond management. The selection of the Wemos D1 R1 and use of the Dissolved Oxygen Sensor enables accurate and efficient measurement of oxygen levels, addressing shortcomings of previous research, especially the integration of the sensor directly into Firebase for real-time data storage and delivery. This development improves connectivity and real-time monitoring capabilities, crucial aspects in ensuring optimal pond water quality. [ABSTRACT FROM AUTHOR]

Cultivation of tiger prawns stands as a crucial sector in Indonesia's fisheries industry, significantly contributing to the country's foreign exchange. However, challenges persist in the cultivation process, particularly concerning suboptimal harvest outcomes. A critical factor in tiger prawn cultivation is the water temperature within shrimp ponds, a parameter directly influencing shrimp growth. The recommended normal temperature range is 28-31°C. Deviations from this range can adversely impact the shrimp's metabolic system and appetite, resulting in stress and potential mortality. Temperature fluctuations can lead to severe issues such as hindered growth, reduced productivity, and increased shrimp mortality. Real-time monitoring of air temperature emerges as a pivotal element in ensuring the success of shrimp farming. This research aims to provide a practical solution for shrimp cultivation by presenting a system that enables farmers to adjust air temperature in ponds in real-time through a user-friendly website application. The ability to promptly respond to abnormal temperature fluctuations empowers farmers to optimize cultivation conditions, thereby reducing shrimp mortality rates. The research focuses on creating a water temperature monitoring system for tiger prawn ponds using cloud storage through the Firebase platform. By implementing real-time temperature monitoring, financial risks for shrimp farmers can be mitigated, preventing losses attributed to temperature-induced shrimp mortality. The research utilizes the DS18B20 temperature sensor and WeMos D1 R2 as the control center. The website displays air temperature measurements, showcasing a high accuracy of 99% with a minimal error of 1.2%. This underscores the system's effectiveness in measuring air temperature both above and below the pond. The incorporation of IoT technology for monitoring water quality in ponds offers a practical and innovative approach to tiger prawn cultivation, with the potential to enhance production outcomes in each harvest. [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]

The objectives of this study were to evaluate the effect of stock enhancement on Penaeus japonicus (Bate, 1888) in Beibu Gulf, South China Sea, and to investigate whether stock enhancement has genetically affected the natural population of P. japonicus in the Beibu Gulf waters. Five microsatellite loci were used to identify released individuals among recaptured specimens. In total, 13 of the 487 recaptured individuals were found with their corresponding parents for this release of shrimp seedlings, accounting for 2.67% of the total recaptured P. japonicus. Furthermore, it was determined that the genetic differences among the broodstock, released, and recaptured populations of P. japonicus were small and did not cause significant changes in the genetic structure of P. japonicus in the area. In conclusion, the stock enhancement of P. japonicus in Beibu Gulf had a certain effect on resource restoration, and there is no difference in the genetic characteristics obtained by the microsatellite markers compared to the original population in this area. [ABSTRACT FROM AUTHOR]

This study developed an individual-rearing method to compare the effects of live feed (sandworms Perinereis aibuhitensis), formulated pellet diets, and a mixture of live feed and formula feed on the Kuruma shrimp Penaeus japonicus, aiming to minimize the influence of non-dietary factors on the growth of P. japonicus, like cannibalism. Results indicated that live feed, with its higher protein, essential amino acids, and fatty acid content, led to significantly better growth and feeding performance in P. japonicus (p < 0.05) compared to pellet diets. A mixed diet resulted in a lower average daily protein intake yet maintained a growth and feeding performance comparable to live feed. The intestinal microbiota of shrimp, dominated by Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria, showed significant shifts with diet changes. Specifically, formulated feed increased the relative abundance of Vibrio and Photobacterium while decreasing Shimia and Rhodobacterales (p < 0.05), and feeding live food resulted in a more complex and stable bacterial network. Notably, individual variances in growth and feeding were observed among shrimps, with some on formulated diets showing growth comparable to those on live feed. Each shrimp’s final weight, specific growth rate, protein efficiency rate, and average daily food intake positively correlated with its initial body weight (p < 0.05), and daily intake varied cyclically with the molting cycle. These findings suggest that individual-rearing is an effective approach for detailed feed evaluation and monitoring in P. japonicus, contributing to improved feed selection, development, and feeding strategies.

Dopamine receptors (DARs) are important transmembrane receptors responsible for receiving extracellular signals in the DAR-mediated signaling pathway, and are involved in a variety of physiological functions. Herein, the D1 DAR gene from Marsupenaeus japonicus (MjDAD1) was identified and characterized. The protein encoded by MjDAD1 has the typical structure and functional domains of the G-protein coupled receptor family. MjDAD1 expression was significantly upregulated in the gills and hepatopancreas after low temperature stress. Moreover, double-stranded RNA-mediated silencing of MjDAD1 significantly changed the levels of protein kinases (PKA and PKC), second messengers (cyclic AMP (cAMP), cyclic cGMP, calmodulin, and diacyl glycerol), and G-protein effectors (adenylate cyclase and phospholipase C). Furthermore, MjDAD1 silencing increased the apoptosis rate of gill and hepatopancreas cells. Thus, following binding to their specific receptors, G-protein effectors are activated by MjDAD1, leading to DAD1-cAMP/PKA pathway-mediated regulation of caspase-dependent mitochondrial apoptosis. We suggest that MjDAD1 is indispensable for the environmental adaptation of M. japonicus. [ABSTRACT FROM AUTHOR]

In a field study, the probiotic effects of a freshwater purple nonsulfur photosynthetic bacterium (PNSB), Rhodobacter sphaeroides, and a marine PNSB, Rhodovulum sulfidophilum, on kuruma shrimp (Marsupenaeus japonicus) were compared by using two commercially operating shrimp ponds. Shrimp were fed with feed containing 0.01% fresh weight (106 cfu/g feed) of PNSB cells for 152 d. The marine PNSB showed a better performance than the freshwater PNSB in average body weight at harvest time, survival rate (P < 0.001 by Fisher's exact test), and feed conversion rate. The effects of freshwater and marine PNSB on shrimp gene expression were also compared by next-generation sequencing and quantitative RT-PCR. Both freshwater and marine PNSB promoted the expression of several genes related to the innate immune system, including NADPH oxidase, superoxide dismutase, lysozyme, antimicrobial peptides, and lectins, and the promotive effect of marine PNSB was stronger than that of freshwater PNSB. The cost of PNSB was calculated to be US$ 0.003–0.005 per kg feed; thus, marine PNSB is a cost-effective and feasible probiotic for shrimp aquaculture. [ABSTRACT FROM AUTHOR]

One of the worst invasive species in terms of outspread and impact, kuruma shrimp Penaeus japonicus has spread subsequently in the Mediterranean basin after being misclassified for the first time as P. canaliculatus in Egypt. At the beginning of the 21st century, however, two morphologically or biometrically similar chromatic patterns of P. japonicus have been proven and clarified as two species. They do not differ morphologically, but genetically separate into form I (P. japonicus) and form II (P. pulchricaudatus). In the present study, we detect the presence and phylogenetic confirmation with mitochondrial cytochrome c oxidase subunit I (COI) gene sequences of the non-indigenous P.pulchricaudatus Stebbing, 1914 in the Mediterranean Sea, formerly accepted P. japonicus. This is the first finding in the Turkish Mediterranean waters and the first confirmation in the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

Recent research on decapod crustaceans revealed the presence of multiple vitellogenin genes within a single species. Characterizing their expression dynamics and regulatory mechanisms is helpful for the sustainability of commercially relevant decapods through a greater comprehension of vitellogenesis. However, it is unclear whether multiple vitellogenin genes exist in the kuruma prawn Marsupenaeus japonicus, an essential species in several Asian countries. This study determined the full-length cDNA sequence of the new vitellogenin (Maj-Vg2) using transcriptome analysis and cDNA cloning. The deduced Maj-Vg2 consisted of 2,554 amino acids and shared only 53.8% identity with Maj-Vg1, the known vitellogenin of this species. The Maj-Vg1 gene (Maj-Vg1) was expressed in both the hepatopancreas and ovary, whereas the Maj-Vg2 gene (Maj-Vg2) was expressed only in the hepatopancreas. Maj-Vg2 expression in the hepatopancreas was low during the previtellogenic stage and increased during the early and late yolk globule stages. When eyestalks were ablated from immature prawns, Maj-Vg2 expression in the hepatopancreas increased significantly, like Maj-Vg1 expression in the ovary, suggesting possible regulation by hormones from the eyestalk ganglia. These results suggested that Maj-Vg2 and Maj-Vg1 are involved in vitellogenesis in this species. [ABSTRACT FROM AUTHOR]

This is the first record of this species from the Canary Islands, as well as from Madeira, both located in the Webbnesia ecoregion (Madeira-Salvage-Canaries; Freitas et al., 2019). The species composition of the superfamily Penaeoidea Rafinesque, 1815 and the fishing effort on aristeids and penaeids (González et al., 2020) in waters off the Canary Islands have received increasing attention from carcinologists in recent years (González & Santana, 2014; Landeira & González, 2018; González & Landeira, 2019; González & Telle, 2021; González-Lorenzo et al., 2021). The shrimp was caught as by-catch of the local artisanal fishery of the scarlet shrimp I Aristaeopsis edwardsiana i (Johnson, 1868) with a specialized, highly selective bottom shrimp-trap (González et al., 2020). On the presence of the deep-water Rose shrimp Parapenaeus longirostris (Decapoda, Dendrobranchiata, Penaeidae) off the Canary Islands. [Extracted from the article]

The discarded species caught in prawn trammel nets damage the nets and cause a serious labor loss problem for fishers. In the present study, a 15 cm high greenhouse plastic film and a greenhouse shade cloth net were fitted between the lower parts of the nets and the lead collars to reduce discards in the trammel net fishery. The modified nets were tested in Mersin Bay with twenty-one fishing operations between September and December 2021. The results showed that, compared to commercial trammel nets, the nets equipped with greenhouse plastic film and greenhouse shade cloth did not significantly reduce the catch of the target species green tiger prawn (Penaeus semisulcatus). However, the total number of discards significantly decreased. The discard rates in the commercial net, greenhouse plastic film net, and greenhouse shade cloth net were 45%, 26%, and 22%, respectively. Furthermore, when the incomes from the nets' hauls were calculated, the net equipped with greenhouse garden film and the net equipped with greenhouse shade cloth generated 24.77% and 14.41% more profit than the commercial net, respectively. [ABSTRACT FROM AUTHOR]

This study aimed to determine the growth, reproduction and mortality rates of Penaeus semisulcatus De Haan, 1844. Samples were collected by bottom trawl net at monthly intervals between June1981 and June1982 from five locations throughout the coastal waters of the north-eastern Mediterranean, Turkey. A total of 1173 specimens were collected. The total length ranged from 7.0 to 25.0 cm with a mean of 16.4 ± 3.0. The total weight varied from 2.2 to 136.0 g with a mean of 41.1 ± 22.9. Length-weight relationship equations were expressed as W = 0.0116 * L2.866 (R²= 0.91, n: 495), W = 0.0074 * L3.052 (R²= 0.96, n: 678) and W = 0.0070 * L3.057 (R²= 0.96, n: 1173) for male, female and combined sexes, respectively. Asymptotic length (L-) and the growth coefficient (k) were estimated at 19.95 and 1.3 year-1 for males, 26.25 and 0.8 year-1 for females and 26.25 and 0.48 year-1 for combined sexes. The instantaneous rates of total (Z), natural (M) and fishing mortalities (F) were 4.34, 2.12 and 2.22 for males, 1.59, 1.02 and 0.57 for females and 2.65, 1.43 and 1.22 year-1 for combined sexes. Using the mortality rates given above, the exploitation rates (E) were 0.51, 0.36 and 0.46 year-1, respectively. The population of P. semisulcatus along the north-eastern Mediterranean coast of Turkey was not strongly affected by fishing during the study period, according to the estimated E values. [ABSTRACT FROM AUTHOR]

This review summarises the current knowledge of mineral nutrition for penaeid shrimp. It investigates how the aquatic environment and the lifecycle of shrimp affect requirements and the role that minerals play in shrimp health. Methods of supplying minerals via either water or to feed, and novel ways of supplementing minerals within feed, are discussed. The requirements for individual minerals are summarised with recommendations for minimum levels of dietary inclusion for semi‐intensive and intensive commercial shrimp culture presented where data permits. Estimates of dietary requirement remain broad for most minerals for the main shrimp production species (Penaeus vannamei, Penaeus monodon and Penaeus japonicus), with some essential minerals remaining unstudied (Table 2 in Section 5.10). Mineral nutrition will become more important as intensification and diversification of production systems provide new challenges to shrimp aquaculture. [ABSTRACT FROM AUTHOR]

The present study was designed to assess the influence of fishmeal replacement with increasing percentages of fresh seafood discards (0, 25, 50 and 75%) in diets for Penaeus japonicus on growth performance, physical characteristics and the chemical and fatty acid composition of shrimp flesh. Each diet was administered for 108 days, and the trial was assayed in triplicate. The final body weight and the specific growth rate were significantly higher (p < 0.05) in shrimps fed with 75% fishmeal replacement as compared to 25%, while the abdomen weight and the total length were the highest (p < 0.01). Moreover, 75% replacement showed a significantly (p < 0.05) lower value of hardness and a greater crude protein and lipid content as compared to the 0% replacement. The shrimps fed with high levels of seafood discards (50 and 75%) showed a lower saturated fatty acid concentration and, in turn, a greater amount of polyunsaturated fatty acids in shrimp meat significantly (p < 0.05) affected the lower atherogenic and thrombogenic indices. In conclusion, replacing 75% of fishmeal with seafood discards provided satisfactory results. An economic analysis based on ESG indicators and PESTLE methodology is provided in order to show the socio-economic and governance impacts affecting the replacement of shrimps’ diet with fish discard.

As the demand for seafood increases, so does the incidence of seafood fraud. Confirming provenance of seafood is important to combat fraudulent labelling but requires a database that contains the isotopic and elemental "fingerprints" of authentic seafood samples. Local isotopic and elemental databases can be scaled up or combined with other databases to increase the spatial and species coverage to create a larger database. This study showcases the use of isotopic and elemental fingerprints of the black tiger prawn (Penaeus monodon) to develop a database that can be used to securely store the data necessary for determining provenance. The utility of this database was tested through querying and building seven different datasets that were used to develop models to determine the provenance of P. monodon. The models built using the data retrieved from the database demonstrated that the provenance of P. monodon could be determined with >80% accuracy. As the database was developed using MySQL, it can be scaled up to include additional regions, species, or methodologies depending on the needs of the users. Combining the database with methods of determining provenance will provide regulatory bodies and the seafood industry with another provenance tool to combat fraudulent seafood labelling. [ABSTRACT FROM AUTHOR]

During the cultivation of Marsupenaeus japonicus, there are often obvious differences in the growth within the same family under the same food, water quality, and environment, which greatly affects cultivation efficiency. To explore the molecular mechanism of this growth difference, this study used RNA-seq technology to compare the transcriptomes of M. japonicus individuals with significant growth differences from the same family. A total of 1375 differentially expressed genes were identified, of which 1109 were upregulated and 266 were downregulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed on the differentially expressed genes, and the results showed that growth-related processes, including chitin metabolism, chitin-binding amino sugar metabolism, and antioxidant processes, including response to oxidative stress, peroxidase activity, antioxidant activity, and peroxidase activity, showed significant differences between the large-size and small-size groups. The expression levels of some differentially expressed genes, such as cuticular protein, low-density lipoprotein receptor, ecdysteroid kinase, myosin heavy chain, and apoptosis inhibitor, were verified by quantitative PCR experiments. One cuticle gene was annotated, and phylogenetic analysis showed that this sequence clustered with the penaeid cuticle genes. This study provides valuable data and a scientific basis for understanding the mechanism of growth differences in M. japonicus at the molecular-genetic level. [ABSTRACT FROM AUTHOR]

The progress of virology research in shrimp has been hampered by a lack of immortalized shrimp cell lines, and even long-term and stable primary cell cultures have not been perfectly achieved. Here, transcriptomic analysis of primary lymphoid cells in kuruma shrimp Marsupenaeus japonicus was performed to understand gene expression changes and stressors under existing culture conditions. In our optimized culture, the primary cells showed dead cell increases on days 3–4 and 6–7 after seeding. Next, we performed transcriptomic analysis at four time points (days 1, 3, 4, and 6 after tissue seeding), and RNA sequencing revealed that detected genes could be divided into three groups according to their expression changes: (1) downregulated on days 3–6, (2) upregulated on days 3–4, and (3) upregulated on day 6. Group 1 included platelet-derived growth factor receptor alpha and vascular endothelial growth factor 3 (MjVEGF3). Consistently, quantitative real-time polymerase chain reaction (qPCR) results showed a significant decrease in MjVEGF3 and its receptor (MjVEGFR) expression. These results suggest the importance of supplementation to recover VEGF signaling in the proper time-dependent manner for long and stable culture of shrimp lymphoid organ cells. [ABSTRACT FROM AUTHOR]

The consumption of raw fish has rapidly increased in recent years, but being a highly perishable product, it is characterised by a very short microbiological shelf life. High hydrostatic pressure (HPP) processing is a nonthermal technology has emerged recently as a promising alternative to thermal processing for food pasteurization capable of maintaining fresh-like characteristics and nutritional value. However, the induced changes in product quality should be assessed carefully. The present research aimed to investigate the effect of HPP on different seafood products, namely grey mullet, tiger prawn and rose shrimp, intended for raw consumption. Three pressure levels (400, 500 and 600 MPa) were applied for 10 min. During refrigerated storage, microbiological quality, chemical parameters, colour and texture and fat oxidation were analysed. Results showed that the application of lower pressure was able to inactivate E. coli, pseudomonas and/or positive coagulase staphylococci; however, they were able to recover during storage. In addition, the application of 600-MPa pressure extended the microbiological shelf life by up to 30 days. For all samples, general whitening occurred while the texture was affected in a different way for the three considered species. Fat oxidation was only minimally affected and remained quite low during storage. [ABSTRACT FROM AUTHOR]

The immune deficiency (IMD) pathway is critical for elevating host immunity in both insects and crustaceans. The IMD pathway activation in insects is mediated by peptidoglycan recognition proteins, which do not exist in crustaceans, suggesting a previously unidentified mechanism involved in crustacean IMD pathway activation. In this study, we identified a Marsupenaeus japonicus B class type III scavenger receptor, SRB2, as a receptor for activation of the IMD pathway. SRB2 is up-regulated upon bacterial challenge, while its depletion exacerbates bacterial proliferation and shrimp mortality via abolishing the expression of antimicrobial peptides. The extracellular domain of SRB2 recognizes bacterial lipopolysaccharide (LPS), while its C-terminal intracellular region containing a cryptic RHIM-like motif interacts with IMD, and activates the pathway by promoting nuclear translocation of RELISH. Overexpressing shrimp SRB2 in Drosophila melanogaster S2 cells potentiates LPS-induced IMD pathway activation and diptericin expression. These results unveil a previously unrecognized SRB2-IMD axis responsible for antimicrobial peptide induction and restriction of bacterial infection in crustaceans and provide evidence of biological diversity of IMD signaling in animals. A better understanding of the innate immunity of crustaceans will permit the optimization of prevention and treatment strategies against the arising shrimp diseases. [ABSTRACT FROM AUTHOR]

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

Several shrimps can survive in a wide range of salinity by changing the concentration of free amino acids to regulate osmotic pressure. In particular, glutamine and alanine increase and decrease significantly depending on environmental salinity. However, there is little information about the enzymes involved in the metabolism of these amino acids. In this study, we focused on glutamine synthetase (GS), which catalyzes the biosynthesis of glutamine in the kuruma shrimp Marsupenaeus japonicus. Although the amino acid sequence of GS from the hepatopancreas has been reported, that of novel GS was determined from the abdominal muscle in this study. We named GSs from the hepatopancreas and abdominal muscle of kuruma shrimp as GS1 and GS2, respectively, and examined their expression levels in kuruma shrimp acclimated at 17, 34 and 40‰ salinity. While the GS1 and GS2 genes were expressed in both muscle and hepatopancreas, the expression level of the GS2 gene was increased in the muscle of shrimp exposed to higher salinities after rearing for 6 h, suggesting that GS2 is involved in the biosynthesis of glutamine in the abdominal muscle to regulate osmotic pressure at high salinity. [ABSTRACT FROM AUTHOR]