Penaeus Japonicus Research Articles

Stochastic Assembly Increases the Complexity and Stability of Shrimp Gut Microbiota During Aquaculture Progression.

The gut microbiota of aquaculture species contributes to their food metabolism and regulates their health, which has been shown to vary during aquaculture progression of their hosts. However, limited research has examined the outcomes and mechanisms of these changes in the gut microbiota of hosts. Here, Kuruma shrimps from the beginning, middle, and late stages of aquaculture progression (about a time duration of 2months between each stage) were collected and variations in the gut microbiota of Kuruma shrimp during the whole aquaculture process were examined. High-throughput sequencing demonstrated increases in the diversity and richness of the shrimp gut microbiota with aquaculture progression. In addition, the gut microbiota composition differed among cultural stages, with enrichment of Firmicutes, RF39, and Megamonas and a reduction in Proteobacteria in the mid-stage. Notably, only very few taxa were persistent in the shrimp gut microbiota during the whole aquaculture progression, while the number of taxa that specific to the end of aquaculture was high. Network analysis revealed increasing complexity of the shrimp gut microbiota during aquaculture progression. Moreover, the shrimp gut microbiota became significantly more stable towards the end of aquaculture. According to the results of neutral community model, contribution of stochastic processes for shaping the shrimp gut microbiota was elevated along the aquaculture progression. This study showed substantial variations in shrimp gut microbiota during aquaculture progression and explored the underlying mechanisms regulating these changes.

Impact of the rearing environment on the metabolism of shrimps and tracing the origins and species of shrimps using specific metabolites.

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.

Presence and Phylogenetic Confirmation of the Non-Indigenous Penaeus pulchricaudatus (Decapoda: Penaeidea) Stebbing, 1914 in the Mediterranean Sea

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.

Effects of Penaeus japonicus stocking density on water quality and bacterial community structure in water in an integrated multi-trophic aquaculture (IMTA) system

Effects of Penaeus japonicus stocking density on water quality and bacterial community structure in water in an integrated multi-trophic aquaculture (IMTA) system

White spot syndrome virus hijacks host PP2A-FOXO axes to promote its propagation

Viruses have developed superior strategies to escape host defenses or exploit host components and enable their infection. The forkhead box transcription factor O family proteins (FOXOs) are reportedly utilized by human cytomegalovirus during their reactivation in mammals, but if FOXOs are exploited by viruses during their infection remains unclear. In the present study, we found that the FOXO of kuruma shrimp (Marsupenaeus japonicus) was hijacked by white spot syndrome virus (WSSV) during infection. Mechanistically, the expression of leucine carboxyl methyl transferase 1 (LCMT1) was up-regulated during the early stages of WSSV infection, which activated the protein phosphatase 2A (PP2A) by methylation, leading to dephosphorylation of FOXO and translocation into the nucleus. The FOXO directly promoted transcription of the immediate early gene, wsv079 of WSSV, which functioned as a transcriptional activator to initiate the expression of viral early and late genes. Thus, WSSV utilized the host LCMT1-PP2A-FOXO axis to promote its replication during the early infection stage. We also found that, during the late stages of WSSV infection, the envelope protein of WSSV (VP26) promoted PP2A activity by directly binding to FOXO and the regulatory subunit of PP2A (B55), which further facilitated FOXO dephosphorylation and WSSV replication via the VP26-PP2A-FOXO axis in shrimp. Overall, this study reveals novel viral strategies by which WSSV hijacks host LCMT1-PP2A-FOXO or VP26-PP2A-FOXO axes to promote its propagation, and provides clinical targets for WSSV control in shrimp aquaculture.

Microsatellite-Marker-Based Evaluation of Stock Enhancement for Kuruma Prawn Pernaeus japonicus in Beibu Gulf, South China Sea

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.

Practice assessment of integrated marine pond aquaculture for increasing benefits and reducing environmental pollution using an ecosystem modeling approach

The transformation from semi-intensive and intensive aquaculture to integrated aquaculture is an effective way to upgrade the aquaculture process. Integrated aquaculture is better able to maintain a healthy environment and a balanced ecosystem for the cultured species as well as producing high quality commodities at a high yield. In this study, we demonstrate that ecosystem modeling can be used to help optimize and promote the integrated aquaculture model. First, the aquaculture management and main biochemical processes were parametrized according to the biological populations present, the physical environment, and the management practices for the integrated aquaculture marine pond of Portunus trituberculatus– Penaeus japonicus– Sinonovacula constricta. The ecosystem model of the pond unit was constructed by coupling the individual growth models of the three cultured animals. The goodness-of-fit indicators showed that this model accurately reproduced the dynamics of the cultured animals, plankton, and nutrients. After the ecosystem model was constructed and validated, the carrying capacity of the integrated aquaculture pond was evaluated by adjusting the stocking density and management practices based on the tailwater discharge standards. The economic benefits of the system and the ecological benefits of polyculture razor clams were quantitatively compared under two scenarios: the current stocking density and reaching the maximum capacity. The assessment results show that the aquaculture pond reached the carrying capacity when the stocking density was 1.8 times the current scenario (18 ind m−2, 27 ind m−2, 22 ind m−2 for P. trituberculatus, P. japonicus and S. constricta). At 1.8 times stocking density scenario, the profit increased by 51.59 %, and nitrogen and phosphorus removal increased by 51.48 % and 55.55 %, respectively. These results provide a theoretical basis for this integrated aquaculture model, which offers a promising way forward for sustainable industrial development. Possible applications and beneficial contributions of this aquaculture model in China are discussed.

Regulation Mechanism of Dopamine Receptor 1 in Low Temperature Response of Marsupenaeus japonicus.

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.

Distribution and role of d-glutamate, a novel d-amino acid identified in animals, in the reproductive tissues of male kuruma prawn Marsupenaeus japonicus.

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 12g, 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.

Evaluating the efficacy of some plant extracts in enhancing the quality of chilled Japanese shrimp (Marsupenaeus japonicus) and controlling histamine formation.

Evaluating the efficacy of some plant extracts in enhancing the quality of chilled Japanese shrimp (Marsupenaeus japonicus) and controlling histamine formation.

Dual roles of crustacean female sex hormone during juvenile stage in the kuruma prawn Marsupenaeus japonicus

The crustacean female sex hormone (CFSH) has been identified as a female-specific hormone that plays a crucial role in female phenotype developments in the blue crab Callinectes sapidus. To date, its homologous genes have been reported in various decapod species. Additionally, unlike the blue crab, several species have two different CFSH subtypes. The kuruma prawn Marsupenaeus japonicus is a representative example species of this phenomenon, having two CFSH subtypes identified from the eyestalk (MajCFSH) and ovary (MajCFSH-ov). Eyestalk-type MajCFSH is expressed predominantly in the eyestalk at the same level in both sexes, indicating no female-specificity. Here, we conducted gene knockdown analysis of eyestalk-type MajCFSH using sexually immature juveniles of kuruma prawn (average body length: ∼10 mm) to elucidate its physiological functions. As a result, MajCFSH-knockdown did not affect the development of sex-specific characteristics such as external reproductive organs, while it induced apparent growth suppression in male juveniles, implying that MajCFSH may play a male-biased juvenile growth role. Moreover, MajCFSH-knockdown female and male juveniles changed their body color to become brighter, indicating that MajCFSH has the ability to change body color by dispersing the pigment granules in the chromatophore. Overall, our present study improved our understanding of the physiological roles of CFSH using kuruma prawn.

Insights Into a Chitin Synthase of Kuruma Shrimp Penaeus japonicus and Its Role in Peritrophic Membrane and Cuticle Formation.

Synthesis of chitin is a subject of great interest in the fields of physiology and immunology of crustaceans. Chitinous tissues include not only the carapace, but also an acellular membrane in the intestine called the peritrophic membrane (PM). Here, we describe the first report of chitin synthase (CHS) of a penaeid shrimp, kuruma shrimp Penaeus japonicus. Histological observations showed that fecal matter in the midgut of kuruma shrimp was wrapped with a PM, which physically separated it from the midgut epithelium. Subsequently, the chitin synthase transcript was amplified from the midgut of the shrimp. The chitin synthase gene of kuruma shrimp (MjCHS) encodes 1,523 amino acid residues. Structural prediction analysis showed that the N-terminal region of MjCHS protein included nine transmembrane helices, the middle region included the catalytic region with several conserved motifs which are found in CHSs from other arthropods, and the C-terminal region included seven transmembrane helices. Although insects have distinct exoskeletal and intestinal chitin synthases, the phylogenetic analysis suggested that crustaceans have a single CHS. MjCHS mRNA was constantly detected in the digestive tract, including the midgut and hepatopancreas of both juvenile and adult kuruma shrimp, suggesting a stable synthesis of chitin in those organs. In contrast, MjCHS mRNA was also detected in the hindgut and uropod of juvenile shrimp. After molting, the mRNA levels of MjCHS in the stomach and uropod were higher than other molting cycles. These results suggest that MjCHS contributes to chitin synthesis in both the digestive tract and the epidermis, providing fundamental insights into chitin synthesis of crustaceans.

Sexual dimorphic eyestalk transcriptome of kuruma prawn Marsupenaeus japonicus

Kuruma prawn (Marsupenaeus japonicus) is a benthic decapod crustacean that is widely distributed in the Indo-West Pacific region. It is one of the most important fishery resources in Japan, but its annual catches have declined sharply since the 1990s. To increase stocks, various approaches such as seed production and aquaculture were attempted. Since the demand for important fishery species, including kuruma prawn, is expected to increase worldwide in the future, there is a need to develop new technologies that will make aquaculture more efficient. Historically, the eyestalk endocrine organ is known to consist of the X-organ and sinus gland (XO/SG) complex that synthesizes and secrets various neuropeptide hormones that regulate growth, molt, sexual maturation, reproduction, and changes in body color. In the current study, eyestalk-derived neuropeptides were identified in the transcriptome. In addition, most orthologs of sex-determination genes were expressed in eyestalks. We identified two doublesex genes (MjapDsx1 and MjapDsx2) and found that MjapDsx1 showed male-biased expression in the eyestalk ganglion with no sex-specific splicing, unlike insect species. Therefore, this study will provide an opportunity to advance the research of neuropeptides and sex determination in the kuruma prawn.

Transcriptome analysis provides insights into the mechanism of carapace stripe formation in two closely related Marsupenaeus species

Marsupenaeus japonicus has two types of phenotypic differences that are mainly reflected in the stripe pattern of the carapace. However, the underlying mechanism regulating the stripe patterns is not clear. In the present study, we first observed the composition of pigment cells and detected the contents of different carotenoids in the carapace of M. japonicus. We clearly observed the setae structure on the carapace. There were red pigment cells in the stripe pattern and yellow pigment cells in the other parts. Both red pigment cells and yellow pigment cells showed dendritic morphology. In the carapace, the content of astaxanthin was the highest, significantly (P < 0.05) higher than that of other carotenoids. Some differentially expressed genes between two pattern types of M. japonicus, may be associated with the body color formation, such as crustacyanin (CRCN), apolipoprotein D (ApoD), tubulin alpha-1 chain, cuticle protein, and ABC transporter, which were verified by quantitative PCR experiments. The amino acid composition and secondary structure of CRCN A2, CRCN C1, and ApoD were significantly different. The results of this study will help to elucidate the molecular mechanism of the differential pattern formation of M. japonicus and provide a reference for further exploration of the formation mechanism of crustacean color.

The interleukin enhancer binding factor-2 (ILF2) gene in Penaeus japonicus shrimp: cloning, tissue distribution, and antiviral effects

The interleukin enhancer binding factor-2 (ILF2) gene in Penaeus japonicus shrimp: cloning, tissue distribution, and antiviral effects

Muscle Transcriptome Analysis Reveals Molecular Mechanisms of Superior Growth Performance in Kuruma Shrimp, Marsupenaeus japonicus

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.

Chemical synthesis of insulin-like peptide 1 and its potential role in vitellogenesis of the kuruma prawn Marsupenaeus japonicus.

The insulin superfamily comprises a group of peptides with diverse physiological functions and is conserved across the animal kingdom. Insulin-like peptides (ILPs) of crustaceans are classified into four major types: insulin, relaxin, gonadulin, and androgenic gland hormone (AGH)/insulin-like androgenic gland factor (IAG). Of these, the physiological functions of AGH/IAG have been clarified to be the regulation of male sex differentiation, but those of the other types have not been uncovered. In this study, we chemically synthesized Maj-ILP1, an ILP identified in the ovary of the kuruma prawn Marsupenaeus japonicus, using a combination of solid-phase peptide synthesis and regioselective disulfide bond formation reactions. As the circular dichroism spectral pattern of synthetic Maj-ILP1 is typical of other ILPs reported thus far, the synthetic peptide likely possessed the proper conformation. Functional analysis using ex vivo tissue incubation revealed that Maj-ILP1 significantly increased the expression of the yolk protein genes Maj-Vg1 and Maj-Vg2 in the hepatopancreas and Maj-Vg1 in the ovary of adolescent prawns. This is the first report on the synthesis of a crustacean ILP other than IAGs and also shows the positive relationship between the reproductive process and female-dominant ILP.

Effects of different dietary carbohydrate-to-protein ratios on the growth performance, antioxidant capacity and energy metabolism in Marsupenaeus japonicus

Four diets containing different carbohydrate-to-protein ratios including the control (18% carbohydrate, 45.98% protein), 0.51 C/P (22% carbohydrate, 43.55% protein), 0.58 C/P (24% carbohydrate, 42.33% protein) and 0.72 C/P (28% carbohydrate, 38.91% protein) were designed to investigate the effects of dietary carbohydrate-to-protein ratios (C/P) on the growth performance, antioxidant capacity and energy metabolism in Marsupenaeus japonicus. Totals of 300 shrimp with an average initial weight of 1.08 ± 0.01 g were randomly assigned to four different dietary treatments. Each treatment included three 300 L tanks, with 25 shrimp in each tank. The results indicated that although growth performance had a decreased trend with increased carbohydrate-to-protein ratios, no overall difference (P > 0.05) was observed. There was a significant decreased trend (P < 0.05) in the acitivity of serum superoxide dismutase (SOD) and glutathione peroxidase (GSH) with the increased carbohydrate-to-protein ratios. It’s worthy noting that inter-tissue differences existed in the antioxidant capacity of M.japonicus in response to dietary different carbohydrate-to-protein ratios. The expression of the antioxidant genes (superoxide dismutase isoform 5, sod-5; peroxiredoxin, prx; ferriten) and heat shock protein 70 in intestine was up-regulated (approximately 20–250 fold) (P < 0.05), while the expression of antioxidant genes (sod-5, prx, ferriten) in hepatopancreas was lowered (P < 0.05) with the dietary increased carbohydrate-to-protein ratios. With the dietary increased carbohydrate-to-protein ratios, energy metabolism genes were up-regulated (P < 0.05) while the pepck1 level was down-regulated (P < 0.05) in the hepatopancreas. In addition, there was a first increased and then decreased trend (P < 0.05) of energy metabolism associated gene expressions in intestine. When shrimp fed with 0.72 C/P diet, although above energy metabolism associated genes expression except pepck1 showed a downward trend, its value was still significantly higher (P < 0.05) compared with the control group. In conclusion, although growth performance was not significantly influenced by different carbohydrate-to-protein ratios, antioxidant capacity and energy metabolism was affected in M.japonicus. The response mechanism to different carbohydrate-to-protein ratios showed tissue-specific. Hepatopancreas and intestine were collaborative to regulate antioxidant and energy metabolism in M.japonicus.

DnaJC16, the molecular chaperone, is implicated in hemocyte apoptosis and facilitates of WSSV infection in shrimp.

Chaperone proteins, including heat shock proteins (HSPs) and DnaJ proteins, are highly conserved and well known for their quick responses to environmental stresses and pathogen infections, especially viruses. However, how DnaJ, an HSP family member, in Penaeus vannamei responds to viral invasion has not been reported. In this research, the novel DnaJ homolog subfamily C member 16-like, or DnaJC16, was characterized in P. vannamei. It contains the DnaJ and thioredoxin domains. Phylogenetic tree analysis demonstrated the conservation of DnaJC16 among penaeid shrimp, where PvDnaJC16 was found to be closely related to DnaJC16 from Fenneropenaeus chinensis and Marsupenaeus japonicus. The transcripts of PvDnaJC16 were expressed in all the tissues tested, and the highest expression was in the lymphoid organs. As hemocytes are major immune tissue, we found significant upregulation of PvDnaJC16 in shrimp hemocytes after white spot syndrome virus (WSSV) infection. Furthermore, the suppression of PvDnaJC16 expression by RNA interference in WSSV-infected shrimp showed a decrease in replication and WSSV copy number. Interestingly, a dramatically high cumulative survival rate following the WSSV challenge (over 60%) was observed in PvDnaJC16-silenced shrimp. Meanwhile, the total hemocyte number was significantly increased in PvDnaJC16 knockdown. In addition, the expression of caspase-3 was reduced, as was the caspase-3/7 activity in PvDnaJC16 silencing. Additionally, the percentage of late apoptotic hemocytes diminished after PvDnaJC16 reduction, whereas the percentage of hemocyte viability increased. Our data reflect the fact that the upregulation of PvDnaJC16 expression upon WSSV infection enhances hemocyte apoptosis, which can accelerate viral spreading in shrimp.

Erratum: Eyestalk Ablation to Increase Ovarian Maturation in Mud Crabs.

Erratum: Eyestalk Ablation to Increase Ovarian Maturation in Mud Crabs.