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The silver pomfret fish Pampus candidus (Previously known as Pampus argenteus Euphrasen) was collected from Iraqi marine waters in the northwest Persian Gulf between April and December 2021, using gillnet and demersal trawling. The lengths and weights of fish were recorded, along with data on the initial maturity length, sex ratio, gonadosomatic index (GSI), Dobriyal index, gonad maturation, development cycle, and absolute fecundity rate. The forked length of female individuals varied from 248 to 281mm, whereas that of male individuals ranged from 124 to 194mm. In July, young fish began to appear. Male individuals had a somehow shorter period of sexual maturity compared to female counterparts. Furthermore, it is noted that males tend to be generally less in size compared to females. The length at first maturity female and male was recorded as 203 and 115mm, respectively. The sex ratio tends to increase for males, and there were two peaks in the rise of the gonadosomatic index and Dobriyal's index, which indicate two periods of spawning activity during June and September. Six stages of fish maturity have been identified, with differences in the size of the eggs. They had a long and continuous breeding season that lasted from May to November, and they spawned by releasing eggs in batches. Notably, they have two distinct reproductive periods: The first during May and June and the second during October and November. The relationship of fecundity with weight was found to be more representative than with length. The document mentions that the silver pomfret spawning and nursery areas are adjacent to the Shatt al-Arab discharge area. [ABSTRACT FROM AUTHOR]

Shukri SM, Setyawan AD, MD Naim D. 2024. Metal concentrations in Silver pomfret Pampus argenteus (Euphrasen, 1788) and its risk assessment in Malaysia. Nusantara Bioscience 16: 13-22. Fish consumption is one of the most important sources of protein in Malaysia. Nevertheless, anthropogenic sources release contaminants, such as metals, which have the potential to accumulate wi thin marine organisms via the food chain. Hence, ingesting fish polluted with metals can be potentially hazardous to human health. This study aimed to ascertain the levels of metal concentrations in the edible tissues of Pampus argenteus (Euphrasen, 1788) inhabiting Malaysian waters to evaluate potential health hazards associated with their use. This study examines the levels of three metals, specifically Cd, Ni, and Pb, in P. argenteus. The samples underwent microwave digestion in a closed vessel to extract metals, which were subsequently analyzed using ICP-OES. The study revealed that the quantities of metals in P. argenteus were primarily Pb, with Ni and Cd following suit. These values ranged from 0.651 mg/kg to 0.001 mg/kg when measured on a dry weight basis. Notably, the samples collected from the Straits of Malacca exhibit a greater concentration of metals than those obtained from the South China Sea region. The tolerable daily intake of P. argenteus from all populations in this study was below the FAO/WHO oral reference dose. The risk assessment results showed that all populations' target hazard quotient was below 1.0. The results indicate that exposure to the metals studied poses a low non-carcinogenic risk and is considered safe for human consumption. This research offers baseline data for evaluating food safety and developing risk management recommendations concerning P. argenteus. [ABSTRACT FROM AUTHOR]

SM, Binashikhbubkr K, Setyawan AD, Md Naim D. 2024. Geometric morphometric divergence of five populations of Pampus argenteus (Euphrasen, 1788) from Malaysian waters. Nusantara Bioscience 16: 1-12. Phenotypic variation in fish may indicate different environmental conditions that affect species' growth and maturation rates and result from genetic factors that allow fish to adapt to different environments. Understanding population structure and dynamics is extremely important for establishing sustainable fisheries. Silver pomfret, Pampus argenteus (Euphrasen, 1788), is an economically important fish species with extensive geographical distribution from the East China Sea to Southeast Asia, Indian Ocean, Arabian Gulf, and the North Sea. It may represent morphologically distinct populations across their range. The main aim of this study is to use geometric morphometric analysis based on physical characteristics to look into the phenotypic diversity of the species across five different populations in Malaysia. Digital images of 260 mature specimens were captured for further analysis. Principle Component Analysis (PCA) and Multivariate analysis (MANOVA) were used in the intra-population analysis based on the transformed distance. At the same time, the Canonical Variance Analysis (CVA) and the Procrustes ANOVA were utilized to determine the inter-population analysis of P. argenteus. The Unweighted Pair Group with Arithmetic Mean (UPGMA) method used to support the analysis has shown that the population is clearly grouped according to homologous body shape. The results show that South, West, and North Coast specimens were grouped while the East Coast and Borneo Island shared in another group. The variations in the body shape of P. argenteus occurred in body depth, caudal region, and head orientation. The findings separated the populations into two main groups representing the marine region to which they belong. This present study is the first report on phenotypic variations of P. argenteus from Malaysian waters utilizing the geometric morphometric method. [ABSTRACT FROM AUTHOR]

In the artificial breeding of Pampus argenteus (Euphrasen, 1788), female fish spawn before male release sperm, which indicates rapid ovarian development. In fish, aromatase is responsible for converting androgens into estrogens and estrogen plays a crucial role in ovarian development. In this study, we aimed to investigate the potential role of brain-type and ovarian-type aromatase to study the rapid ovarian development mechanism. The results showed that cyp19a1a was mainly expressed in the ovary and could be classified as the ovarian type, whereas cyp19a1b could be considered as the brain type for its expression was mainly in the brain. During ovarian development, the expression of cyp19a1a in the ovary significantly increased from stage IV to stage V and Cyp19a1a signals were present in the follicle cells, while cyp19a1b expression in the pituitary gland decreased from stage IV to stage V. To further investigate the function of Cyp19a1a, recombinant Cyp19a1a (rCyp19a1a) was produced and specific anti-Cyp19a1a antiserum was obtained. The expressions of cyp19a1a, estrogen receptors 2 alpha (esr2a), and androgen receptor alpha (arα) were significantly upregulated in the presence of rCyp19a1a. Meanwhile, cyp19a1a was expressed significantly after E2 treatment in both ovarian and testicular tissue culture. Taken together, we found two forms of aromatase in silver pomfret. The ovarian-type aromatase might play an important role in ovarian differentiation and maturation, and participate in E2 synthesis through co-regulation with esr2a. The brain-type aromatase cyp19a1b might be involved in the regulation of both brain and gonadal development. [ABSTRACT FROM AUTHOR]

In this study, three genes associated with the metabolism of Pampus argenteus, namely dehydropeptidase (dp), carboxypeptidase A (cpa), and sulfotransferase (sult), were cloned and evaluated using transcriptomics analysis, and their functions in the digestion and absorption of jellyfish were discussed. First, full-length cDNA sequences for dp1, cpa2l, and sult2 were cloned using RACE and confirmed using sequencing. The total length of the dp1 was 2 522 bp, with this transcript including an open reading frame (ORF) of 1 272 bp, a signal peptide composed of 23 amino acids, and an amide hydrolase superfamily domain. The cpa2l transcript was 1 421 bp long and encoded a 1 260 bp ORF. This protein consisted of a signal peptide of 16 amino acids and was characterized by a typical M14 metal carboxypeptidase family domain. sult2 was 1 834 bp in length, producing an ORF of 714 bp, which included a typical sulfatase domain. In addition, homology evaluations of these three P. argenteus genes revealed that they were most similar to the bluefin tuna (Thunnus maccoyii), and phylogenetic tree analysis showed that dp1, cpa2l, and sult2 were all closely related to their corresponding genes from T. maccoyii. RT-qPCR was then used to evaluate the expression levels of these three genes in different tissues and the changes in expression patterns in response to jellyfish ingestion. These experiments revealed that dp1 expression was naturally the highest in the liver (P < 0.05) and significantly increased in the brain, gills (P < 0.01), midgut, and kidney (P < 0.05), but significantly decreased in the muscle (P < 0.05) when compared to that in the non-feeding control. cpa2l expression was highest in the middle intestine in the non-jellyfish feeding group and the kidney in the jellyfish feeding group (P < 0.05) and was shown to be significantly increased in the liver (P < 0.01) but significantly decreased in the midgut and muscle (P < 0.01) when compared to that in the non-feeding group. sult2 expression was highest in the liver (P < 0.05) and significantly increased in the midgut, brain, gill, liver, and kidney in the feeding group compared to that in the non-feeding group (P < 0.05). Taken together, these results suggest that dp1, cpa2l, and sult2 play important roles in nutrient digestion, absorption, and metabolism in P. argenteus, especially in response to jellyfish feeding. In addition, the results of the tissue expression patterns for each of these genes following jellyfish ingestion suggest that dp1 is primarily involved in the regulation of digestion, absorption, and nutrient deposition; cpa2l is involved in the regulation of nutrient metabolism in the liver; and sult2 may play an important role in the overall process of digestion, absorption, and metabolism.

We cultured silver pomfret for 20 days, decreasing water temperature from 18 to 8 ℃, and sampled muscle every 5 days. Muscle fiber degeneration and apoptosis began to increase at 13 ℃ detected by HE and TUNEL staining. Further analysis of transcriptome revealed that several apoptosis-related pathways were highly enriched by differentially expressed genes (DEGs). We analyzed 10 DEGs from these pathways by RT-qPCR during the temperature-decreasing process. JNK1, PIDD, CytC, Casp 3, and GADD45 were up-regulated after 15 and 20 days, while DUSP3, JNK2, and PARP genes were down-regulated after 15 and 20 days. DUSP5 was up-regulated from 10 to 20 days, and C-JUN was up-regulated after 20 days. We analyzed apoptosis in PaM cells under different temperatures (26 ℃, 23 ℃, 20 ℃, 17 ℃, and 14 ℃). The cell viability significantly declined from 14 to 20 ℃; the TUNEL and IHC results showed that the apoptosis signal increased with the temperature dropping, especially in 17 ℃ and 14 ℃; DUSP5, JNK1, CytC, C-JUN, Casp 3, and GADD45 were up-regulated at 17 ℃ and 14 ℃, and PIDD was up-regulated at 20 ℃, 17 ℃, and 14 ℃. DUSP3 was up-regulated at 20 ℃ but down-regulated at 17 ℃ and 14 ℃, and PARP was down-regulated at 17 ℃ and 14 ℃. JNK2 was up-regulated at 20 ℃ but down-regulated at 17 ℃ and 14 ℃. Our results suggest that DUSP could help inhibit apoptosis in the initial stage of cold stress, but low temperature could down-regulate it and up-regulate JNK-C-JUN, inducing apoptosis in a later stage. These data provide a basis for the study of the response mechanism of fish to cold. [ABSTRACT FROM AUTHOR]

Fish cell lines have become a useful tool to study in resource conservation, genetic breeding, diseases control, and environmental pollutants detection. The silver pomfret (Pampus argenteus) is a high‐valued marine fish species in aquaculture, which is seriously threatened by various fish diseases. In this study, a new cell line derived from P. argenteus liver (PaL) was established and characterized. PaL cells mainly consisted of fibroblast‐like morphology and multiplied well in Leibovitz's L‐15 medium supplemented with 15% foetal bovine serum and 3 ng/mL basic fibroblast growth factor at 22°C. Amplification of the Cyt b gene confirmed that the origin of PaL cells as P. argenteus. Chromosome analysis revealed that PaL cells had a diploid Karyotyp. The PaL cells were efficiently transfected with pEGFP‐N3 plasmids, indicating its potential application in foreign gene manipulation studies. The PaL cells were found to be susceptible to red sea bream iridovirus (RSIV) and the expression of immune‐related gene (TLR5) and apoptosis‐related genes (Bax, Cyt c3, CASP9) were upregulated. Furthermore, lipopolysaccharide and palmitic acid (PA) treatments decreased cell viability and up‐regulated the expression of inflammation related genes (IL‐8, IL‐1β). Meanwhile, PA incubation induced cell apoptosis by Bcl‐2‐regulated caspase activation. In conclusion, the newly established PaL cell line will be an appropriate in vitro tool for viral propagation and immune response. [ABSTRACT FROM AUTHOR]

Pampus argenteus is important for commercial fishery catch species and is an emerging target for aquaculture production. Notably, P. argenteus has a bizarre morphology and lacks pelvic fins. However, the reason for the lack of pelvic fins remains unclear, ultimately leading to frequent upside-down floating of P. argenteus during breeding and marked consumption of physical energy. Some lineages, including whales, fugu, snakes, and seahorse, independently lost the pelvic appendages over evolutionary time. Do different taxa employ the same molecular genetic pathways when they independently evolve similar developmental morphologies? Through analysis of the gene responsible for appendage localization, Hoxd9, it was discovered that the Hox domain was absent in the Hoxd9 gene of P. argenteus, and the Hoxd9b gene lacked the Hox9 activation region, a feature not observed in the Hoxd9 gene of other fish species. Interestingly, those distinctive characteristics are not observed in the Hoxd9 gene of other fish species. To determine the association between the Hoxd9 gene characteristics and the pelvic fin deletion in P. argenteus, the full-length cDNA of the Hoxd9a gene was cloned, and morphological observations of the species' juveniles were performed using stereomicroscopy and scanning electron microscopy. Thereafter, the tissue localization of Hoxd9a in the species was analyzed at the gene and protein levels. Based on the results, deletion of the Hoxd9a structural domain possibly leads to disruptions in the protein translation and the pelvic fin localization in P. argenteus during its early ontogenetic developmental stage, resulting in the absence of pelvic fins. [ABSTRACT FROM AUTHOR]

Photoperiod has a great influence on the growth and ovarian development and maturation of fishes. To analyse the effects of photoperiod on growth and ovarian development of an important marine economic fish, silver pomfret Pampus argenteus, short photoperiod group (L:D = 8:16), control group (L:D = 12:12) and long photoperiod group (L:D = 18:6) were set up for 60 days. The growth performance, ovarian development, changes in hormones and key enzyme activities in the hypothalamic–pituitary−gonadal (HPG) axis and expressions of key regulatory genes in the HPG axis were studied under different photoperiod conditions. The results showed that the final weight gain, body weight index, specific growth rate for weight, specific growth rate for length and average daily growth were the highest in the long photoperiod group, and the feed conversion rate was the lowest. Under long photoperiod condition, gonado‐somatic index and hepato‐somatic index were higher, ovarian maturity was better and expressions of HPG axis−related regulatory genes foxl2a, foxl2b, cyp19a1a, cyp19a1b, kiss, gpr54‐2, gnrh2, fsh and lh were higher. When compared with the other two groups, in the long photoperiod group, the change trend of estradiol (E2) was consistent with those of luteinizing hormone, melatonin (MT) and kisspeptin, and the levels were higher on the 20th and 50th days. These results indicate that prolongation of the photoperiod can improve the growth performance of P. argenteus and promote ovary development and maturation. The authors speculate that photoperiod may regulate the ovarian activity of P. argenteus through MT and kisspeptin/gpr54 signalling pathways. The results show that photoperiod can regulate the ovarian development of P. argenteus, which would help in breaking the seasonal restrictions of animals and regulating an animal's reproductive cycle. [ABSTRACT FROM AUTHOR]

Vitellogenesis is the main event of oocyte growth in oviparous animals, which is mainly manifested by the accumulation of vitellogenin (VTG). The accumulation of vitellogenin depends mainly on the absorption of exogenous vitellogenin, which enters oocyte through endocytosis mediated by its receptor (VGR). We investigated the expression and localization of VTG and VGR during gonad development of Pampus argenteus. The qPCR results show that vtgs were not expressed in male fish, but in the ovary and liver of female fish; the expression levels went up at first and then down. The expression levels of vgr in the testis were low and only 1%–3% of that in ovary. ELISA results show that during the ovarian development of P. argenteus, VTG in liver, serum, and ovary all showed a trend from increasing to decreasing. However, VTG in liver peaked in Stage IV, and in serum and ovary peaked in Stage V, reflecting changes in the characteristics of VTG in the liver (synthesis), blood (transport), and ovaries (accumulation). During gonad development, VGR in the ovaries first increased and then decreased, reaching a peak in Stage V, in contrast to vgr mRNA expression. The VGR content in the testis was extremely low and stable, consistent with vgr mRNA. Immunohistochemistry results show that the location and intensity of VTG and VGR positive signals were synchronized with the changes of their protein content, which revealed that VTG was mainly synthesized in the liver cytoplasm, secreted into the blood, and transported to ovary in Stage III. VGR is highly expressed in oocytes in Stage II. In Stage III, a large amount of VTG reaches the ovary, when VGR begins to translate and is subsequently transported to the plasma membrane of the oocyte. Therefore, the positive signal of VGR was stronger near the plasma membrane of oocytes in Stages I and II. By using qPCR, ELISA, and immunohistochemistry, the synthesis, transport, and accumulation of vitellogenin were elucidated and the mechanism of its endocytosis on egg membrane mediated by VTG during the development of P. argenteus was revealed preliminarily. [ABSTRACT FROM AUTHOR]

Silver pomfret (Pampus argenteus) is one of the most important fishery products in the Indo‐Pacific Ocean. Nonetheless, little is known about the genetic parameters of economic traits. To determine whether the selective breeding programme would improve economic traits, the authors evaluated the growth performance of the selected group and the control group at 60, 90 and 120 days, and the growth performance parameters of the selected group were higher than those of the control group. Through Pearson correlation analysis, the authors found that the morphological traits that are highly related to the weight of P. argenteus are body length and body height. Genetic gain and realized heritability for body weight were highest at day 90, which were 12.72% and 0.23%, respectively. Therefore, the authors speculate that day 90 may be a critical time for screening. The average coefficient of variation for body weight reached over 30%. All three morphological traits reached moderate realized heritability at day 90 after hatching. These implied that selective breeding has the potential to improve the growth traits of P. argenteus. In addition, the reproductive performance of P. argenteus parent fish was obviously improved after gonadal strengthening. These results provide important information for future breeding programmes for P. argenteus. [ABSTRACT FROM AUTHOR]

Schizochytrium sp. is a kind of heterotrophic protist, rich in docosahexaenoic acid (DHA). To study the application value of Schizochytrium sp. in fish diet, a 20-day feeding experiment was initiated to evaluate its effect on growth, fatty acid contents, and the gut microbiota of the important economic fish, silver pomfret. In this study, the diets of the treatment group were added with 2% Schizochytrium sp. The fish in the treatment group gained more weight and had a higher growth rate than the control group. The levels of DHA, eicosapentaenoic acid, and polyunsaturated fatty acids in the edible tissue of fish were highly increased in the treatment group after 20 days. After feeding Schizochytrium sp., high-throughput 16S rRNA sequencing showed that the Proteobacteria, Firmicutes and Bacteroidetes were the phyla with the highest abundance, and at the genus and species level, we observed an increased abundance of probiotics. The results indicated that ingestion of Schizochytrium sp. could change the dominant microbiota population, which might lead to accelerated growth and improved unsaturated fatty acid content and fish health. This study provides a reference for Schizochytrium sp. supplementation in fish diets and could aid in the industrialization of silver pomfret. [ABSTRACT FROM AUTHOR]

The intensity of light has been known to play a crucial role in the growth and developmental processes of fish through the visual system. To investigate effects of light intensity on the growth, feeding patterns, retinal structure, and vision-related genes of silver pomfret, we set four groups including control (natural light), L0 (darkness), L100 (100 lux), and L1000 (1000 lux) at larval, juvenile and young stages. Full length and survival rate were significantly lower in L0 at larval and juvenile, while feeding rate was significantly higher in control and L1000; at young stage, weight and feeding rate was significantly lower in L0 and specific growth rate was significantly higher in control; but there was no significant difference in condition factor among four groups. Next, at larvae stage, we observed a clear ten-layer structure of the retina, which developed better in high light intensity groups; the number of melanin particles in pigment epithelial layer also increased with development of retina; at juvenile and young stages, low light intensity led to aggregation of melanin particles, and thickness of ganglion cell layer became thinner, with cell body decreasing to one layer in high light intensity groups. Finally, we examined expression of seven vision-related genes: RH1 gene was up-regulated at larvae stage and down-regulated at juvenile and young stages in L0 and L100, and RH2 and LWS initially increased and then declined with the development of the fish in control; conversely, SWS, SWS2, RPE65, and RBP were up-regulated in high light intensity groups. In conclusion, our study suggests that high light intensity can lead to improved growth and feeding patterns in fish, as well as promoting the development of retina and up-regulating the expression of pigment genes. Consequently, our findings provide a valuable theoretical foundation for optimizing the lighting scheme of the artificial breeding process of silver pomfret.

In the artificial breeding of Pampus argenteus (Euphrasen, 1788), female fish spawn before male release sperm, which indicates rapid ovarian development. In fish, aromatase is responsible for converting androgens into estrogens and estrogen plays a crucial role in ovarian development. In this study, we aimed to investigate the potential role of brain-type and ovarian-type aromatase to study the rapid ovarian development mechanism. The results showed that cyp19a1a was mainly expressed in the ovary and could be classified as the ovarian type, whereas cyp19a1b could be considered as the brain type for its expression was mainly in the brain. During ovarian development, the expression of cyp19a1a in the ovary significantly increased from stage IV to stage V and Cyp19a1a signals were present in the follicle cells, while cyp19a1b expression in the pituitary gland decreased from stage IV to stage V. To further investigate the function of Cyp19a1a, recombinant Cyp19a1a (rCyp19a1a) was produced and specific anti-Cyp19a1a antiserum was obtained. The expressions of cyp19a1a, estrogen receptors 2 alpha (esr2a), and androgen receptor alpha (arα) were significantly upregulated in the presence of rCyp19a1a. Meanwhile, cyp19a1a was expressed significantly after E2 treatment in both ovarian and testicular tissue culture. Taken together, we found two forms of aromatase in silver pomfret. The ovarian-type aromatase might play an important role in ovarian differentiation and maturation, and participate in E2 synthesis through co-regulation with esr2a. The brain-type aromatase cyp19a1b might be involved in the regulation of both brain and gonadal development.

The pharyngeal sac is a comparatively rare organ in the digestive tract among teleost fishes. However, our understanding of this remarkable organ in the silver pomfret (Pampus argenteus) is limited. In the present study, we examined the various morphological and histological characteristics of the pharyngeal sac using histochemical techniques and electron microscopy. The pharyngeal sac showed unique characteristics such as well-developed muscular walls, weakly keratinized epithelium, numerous goblet cells, and needle-like processes on the papillae. The porous cavity of the papillae contained numerous adipocytes and was tightly enveloped by type I collagen fibers. These structures might provide mechanical protection and excellent biomechanical properties for grinding and shredding prey. A comparison of gene expression levels between the pharyngeal sac and esophagus using RNA-seq showed that phenotype-associated genes (epithelial genes and muscle genes) were upregulated, whereas genes related to nutrient digestion and absorption were downregulated in the pharyngeal sac. These results support the role of the pharyngeal sac in shredding and predigesting food. Overall, these findings provide a clearer understanding of the pharyngeal sac morphology and explain the morphological adaptations of the digestive tract for feeding on gelatinous prey. To our knowledge, this is the first report on pharyngeal sac gene expression in P. argenteus. [ABSTRACT FROM AUTHOR]

Our study delved into exploring the bacterial profiles and volatile compounds during the fermentation of two distinct fish sauces, i.e., Larimichthys polyactis (LP) and Pampus argenteus (PA), and a co-occurrence network was employed to investigate the underlying relationship between flavor and microorganisms. The pH (6.97–5.66) remarkably declined while the total volatile basic nitrogen (TVB-N, 92.36–116.55 mg/100 mL) and amino acid nitrogen (AAN, 104.49–638.68 mg/100 mL) contents gradually rose with the fermentation of LP and PA samples. Bacterial community analysis revealed that Psychrobacter was the dominant genus before LP fermentation, and its relative abundance was gradually occupied by Staphylococcus after 7M. The most dominant genus before PA fermentation was Photobacterium , while Virgibacillus emerged as the predominant genera of PA samples after 7M. Seven main volatile compounds made salient contributions (VIP ≥1.0, ROAV ≥1.0) to the flavor of LP- and PA-fermented samples, respectively. Among them, three typical genera (Tetragenococcus , Streptococcus and Staphylococcus) and four specific genera (Tetragenococcus , Psychrobacter , Vagococcus and Lactobacillus) were the core microorganisms contributing to flavor compounds in LP and PA samples, respectively. Therefore, acquiring insight into the microbes responsible for key flavors in multi-variety fermented fish sauces could provide essential indicators for optimizing commercial fermentation processes. • LP- and PA-fermented fish sauces at different stages were prepared. • 7 and 7 flavor compounds made salient contribution to the LP and PA fish sauces. • Microbial profiles exist differences among two samples and four fermentation stages. • Co-occurrence network model elucidated microbe correlations with volatile compounds. • 3 and 4 core genera were well related to key flavor compounds in LP and PA samples. [ABSTRACT FROM AUTHOR]

Silver pomfret, an economically important fish species, encounters significant challenges posed by copper pollution in wild and culturing environment. High level of copper has the potential to accumulate in aquatic organisms over prolonged exposure periods. The extracellular matrix, which is highly susceptible to copper, encompasses various proteins, among which tenascin (TN) might play a crucial role in potentially regulating copper-induced apoptosis. To investigate this hypothesis in fish, we initially identified six TN family members in silver pomfret, namely TNCa , TNCb , TNR , TNXB , TNXBa and TNN. Phylogenetic analysis showed four gene subfamilies, namely TNC, TNR, TNN, and TNX, through comparative analysis with TNs from seven other teleost fish species. Subsequently, we analyzed transcriptome of silver pomfret under copper stress and found differential expression of TN family genes under varying levels of copper stress, particularly TNCa. KEGG enrichment analysis demonstrated a significant enrichment of TN downstream pathway, specifically the Pi3K-AKT signaling pathway. RT-qPCR results indicated up-regulation of TNs and apoptosis inhibition-related genes and down-regulation of apoptosis promotion-related genes within this pathway. Hence, we speculated that TN inhibits copper-induced apoptosis by modulating this particular pathway. To further validate this hypothesis, we established a copper stress cell model using a silver pomfret kidney cell line (PaK) and utilized siRNA to knock down TNCa expression within this cellular model. Comparing RNAi-Cu group to NC-control group, we observed significantly reduced cell viability and intensified apoptosis signals in the former. Additionally, RNAi-Cu group displayed down-regulation of apoptosis inhibition-related genes and up-regulation of apoptosis-related genes in Pi3K-AKT signaling pathway compared to NC-Cu group. These findings indicated that TN might be able to inhibit copper-induced apoptosis through Pi3K-AKT signaling pathway. Ultimately, this study offers foundational knowledge for exploring heavy metal toxicity effect on fishes and some references for utilization of copper in parasite control. [Display omitted] • We initially identified six tenascin family members in silver pomfret. • Phylogenetic analysis revealed four tenascin subfamilies in silver pomfret. • TN can inhibit copper-induced apoptosis through the Pi3K-AKT signaling pathway. [ABSTRACT FROM AUTHOR]

Background: Silver pomfret (Pampus argenteus) is one of the most widely distributed and economically important pelagic fish species. However, an unique morphological feature of P. argenteus is the loss of pelvic fins, which can increase the energy requirement during food capture to some extent and is therefore not conducive to artificial culture. Tbx4/5 genes are highly conserved regulatory factors that regulate limb development in vertebrates and are in turn regulated by microRNAs (miRNAs). However, the miRNAs that directly regulate the Tbx4/5 genes in P. argenteus remain to be elucidated. Methods: The Tbx4/5 genes of P. argenteus were first cloned, and the small RNA transcriptomes were sequenced by high-throughput sequencing during the critical period of the fin development at days 1, 7, and 13 of hatching. The miRNAs regulating the Tbx4/5 genes of P. argenteus were subsequently predicted by bioinformatics analysis, and the related miRNAs were verified in vitro using a dual fluorescence reporter system. Results: A total of 662 miRNAs were identified, of which 257 were known miRNAs and 405 were novel miRNAs were identified. Compared to day 1, 182 miRNAs were differentially expressed (DE) on day 7, of which 77 and 105 miRNAs were downregulated and upregulated, respectively, while 278 miRNAs were DE on day 13, of which 136 and 142 miRNAs were downregulated and upregulated, respectively. Compared to day 13, four miRNAs were DE on day 7, of which three miRNAs were downregulated and one miRNA was upregulated. The results of hierarchical clustering of the miRNAs revealed that the DE genes were inversely expressed between days 1 and 7, and between days 1 and 13 of larval development, indicating that the larvae were in the peak stage of differentiation. However, the number of DE genes between days 7 and 13 of larval development was relatively small, suggesting the initiation of development. The potential target genes of the DE miRNAs were subsequently predicted, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of target genes were performed. The results suggested that the DE miRNAs were involved in growth, development, and signal transduction pathways, of which the Wnt and Fgfs signaling pathways are known to play important roles in the growth and development of fins. The results of dual fluorescence reporter assays demonstrated that miR-102, miR-301c, and miR-589 had a significant negative regulatory effect on the 3?Œ-UTR of the Tbx4 gene, while miR-187, miR-201, miR-219, and miR-460 had a significant negative regulatory effect on the 3′-UTR of the Tbx5 gene. Altogether, the findings indicated that miRNAs play an important role in regulating the growth and development of pelvic fins in P. argenteus. This study provides a reference for elucidating the interactions between the miRNAs and target genes of P. argenteus in future studies. [ABSTRACT FROM AUTHOR]

Insulin-like growth factor 3 plays an important role in gonad development in teleost fish. Previous studies found that igf3 was specifically expressed in gonads of silver pomfret (Pampus argenteus). Unlike in other fish, IGF3 is a membrane protein in silver pomfret, and its specific role in gonads is unclear. Herein, we explored the importance of IGF3 in oogenesis and spermatogenesis in silver pomfret by analyzing gene expression and cellular localization. During follicular development, igf3 was detected in ovaries at both mRNA and protein levels during the critical stages of vitellogenesis (IV–VI). Localization analysis detected igf3 mRNA and protein in somatic cells, including theca and granulosa cells around oocytes. Similar to cathepsin L and cathepsin K, igf3 was consistently expressed in ovaries during vitellogenesis, suggesting that it might play a key role in vitellogenesis of oocytes. During spermatogenesis, igf3 mRNA and protein levels were high in stages II, IV, and V, similar to sycp3 and dmc1, and the highest igf3 mRNA and protein levels were reached in stage VI. Furthermore, igf3 mRNA and protein were detected in spermatogonia, spermatocytes, spermatids, and surrounding Sertoli cells, but not in spermatozoon, indicating that IGF3 might be involved in differentiation and meiosis of spermatogonia. [ABSTRACT FROM AUTHOR]

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The present study aimed at assessing the impact of addition of fumaric acid (0.5%), as an active agent, in a corn starch (2%) based edible coating, on the lipid quality and microbial shelf life of silver pomfret (Pampus argenteus) fish steaks stored at 4 °C. Treating fish steaks with FA resulted in a bacteriostatic effect leading to reduced counts of total mesophilic and psychrotrophic bacteria, H2S producing bacteria and Pseudomonas spp. The total mesophilic bacterial count of uncoated control sample exceeded the permissible limit of 7 log cfu g−1 on 6th day and had the lowest microbial shelf life. FA incorporation in the CS coating improved the microbial stability of fish steaks resulting in a shelf life of 15 days. The outcomes of the study suggest that CS based coating is beneficial in delaying lipid oxidation as displayed by the lower TBA and PV values while FA is an effective agent for further increasing the preservative action of CS coating by significantly inhibiting microbial growth as well as lipid quality deterioration, which could be exploited by the seafood industry as an active packaging component. [ABSTRACT FROM AUTHOR]

Silver pomfret (Pampus argenteus) is an economically important mariculture species. However, little is known about the genetic parameters of its commercially important traits. In order to determine whether continuous progress can be achieved by selection for growth, we took the body weight trait of East China Sea P. argenteus as the target trait of mass selection. The realized heritability of P. argenteus from the selected group and control group was analyzed at the three growth times (60, 90, and 120 days). The results showed that the growth performance parameters of the selected group in the third month post hatching were higher than those in the control group, but the opposite results were found in the fourth month. The morphological traits highly correlated with the body weight of P. argenteus were found by Pearson correlation analysis and path analysis, which were body length and tail length, respectively. On the 60th, 90th, and 120th days after hatching, the genetic gains of body weight trait in the selected group were 9.44%, 17.64%, and 15.18%, respectively, and the mean values of realized heritability were at moderate level. Nevertheless, in the selected group, the genetic variation values of the two morphological traits significantly related to body weight were all below 10%, and the genetic gains were relatively low and stable, but the genetic variation values of body weight trait in the selected group were above 20%, and genetic gains were relatively high. These implied that it is possible to obtain considerable genetic gains by selecting for body weight trait, and the results provide supportive evidence for the continuity of the P. argenteus-selective breeding program.

Abstract The present investigation was aimed to examine the percentage quantity of protein and amino acids in scales and muscles of Pampus argenteus and Parastromateus niger gathered from the local fish market of district Quetta of Balochistan. About 80 specimens of these two species, i.e., Pampus argenteus (N=40) and Parastromateus niger (N = 40), were collected from April 2017 to May 2018. In general, crude protein content was high in scales, that is, 71.03% in Parastromateus niger and 52.11% in Pampus argenteus, as well as in muscles of two Pomfret species of fishes i.e., 63.44% in Pampus argenteus and 60.99% in Parastromateus niger on a dry-weight basis, respectively. Likewise, the muscles and scales of Parastromateus niger reveal well compositions of amino acids that include proline was found to be high, and methionine was less than other amino acids, whereas threonine was found high in the scales of Pampus argenteus, but methionine was observed in lesser amount. However, the amino acids found in Pampus argenteus muscles also showed different compositions, such as lysine was found to be high, but histidine was less, respectively. In comparison, amino acids like tryptophan and cysteine were not detected in both scales and muscles of thesePomfret species of fishes. Thus, this study was based on analyzing the utilization of both Pomfret species of scales and meat whether they could have values as good supplements of both protein and certain kinds of essential amino acids in animal diets.

Pampus argenteus is important for commercial fishery catch species and is an emerging target for aquaculture production. Notably, P. argenteus has a bizarre morphology and lacks pelvic fins. However, the reason for the lack of pelvic fins remains unclear, ultimately leading to frequent upside-down floating of P. argenteus during breeding and marked consumption of physical energy. Some lineages, including whales, fugu, snakes, and seahorse, independently lost the pelvic appendages over evolutionary time. Do different taxa employ the same molecular genetic pathways when they independently evolve similar developmental morphologies? Through analysis of the gene responsible for appendage localization, Hoxd9, it was discovered that the Hox domain was absent in the Hoxd9 gene of P. argenteus, and the Hoxd9b gene lacked the Hox9 activation region, a feature not observed in the Hoxd9 gene of other fish species. Interestingly, those distinctive characteristics are not observed in the Hoxd9 gene of other fish species. To determine the association between the Hoxd9 gene characteristics and the pelvic fin deletion in P. argenteus, the full-length cDNA of the Hoxd9a gene was cloned, and morphological observations of the species’ juveniles were performed using stereomicroscopy and scanning electron microscopy. Thereafter, the tissue localization of Hoxd9a in the species was analyzed at the gene and protein levels. Based on the results, deletion of the Hoxd9a structural domain possibly leads to disruptions in the protein translation and the pelvic fin localization in P. argenteus during its early ontogenetic developmental stage, resulting in the absence of pelvic fins.

Schizochytrium sp. is a kind of heterotrophic protist, rich in docosahexaenoic acid (DHA). To study the application value of Schizochytrium sp. in fish diet, a 20-day feeding experiment was initiated to evaluate its effect on growth, fatty acid contents, and the gut microbiota of the important economic fish, silver pomfret. In this study, the diets of the treatment group were added with 2% Schizochytrium sp. The fish in the treatment group gained more weight and had a higher growth rate than the control group. The levels of DHA, eicosapentaenoic acid, and polyunsaturated fatty acids in the edible tissue of fish were highly increased in the treatment group after 20 days. After feeding Schizochytrium sp., high-throughput 16S rRNA sequencing showed that the Proteobacteria, Firmicutes and Bacteroidetes were the phyla with the highest abundance, and at the genus and species level, we observed an increased abundance of probiotics. The results indicated that ingestion of Schizochytrium sp. could change the dominant microbiota population, which might lead to accelerated growth and improved unsaturated fatty acid content and fish health. This study provides a reference for Schizochytrium sp. supplementation in fish diets and could aid in the industrialization of silver pomfret.

Temperature is a major environmental factor influence fish growth, development, metabolism and physiological performance. Silver pomfret (Pampus argenteus) is an economically important fishery species, however, the molecular mechanisms responsive to long-term cold stress are still unclear. Hence, we altered water temperature from 13 °C to 8 °C, a logistic fit curve for the survival rate of P. argenteus under a gradient cold stress were thus achieved, 50% survival rate at a measured temperature of 7 °C–7.5 °C. After stimulation, the gill, liver and muscle tissues were investigated through transcriptome, antioxidant enzymes and histological observation. The results showed that antioxidant enzyme and Na+-k+ ATPase activity in gill tissue was significantly increased, tissue damage and apoptosis were observed in multi-tissues. By high-throughput sequencing, a total of 618,097,404 reads of raw data and 598,855,490 reads of clean data were obtained, containing 12,489 differently expressed genes (DEGs). KEGG pathway enrichment analysis showed that DNA replication, protein digestion and absorption, cardiac muscle contraction, adrenergic signaling in cardiomyocytes, and metabolic pathways were significantly enriched in multi-tissues. Fifteen DEGs were selected for real-time PCR (RT-qPCR) analysis, and the results were consistent with transcriptome profiling. Based on the results, we inferred that P. argenteus survived at low temperatures may be achieved by improving the ability to scavenge oxyradical substance and enhancing cell fluidity. This present study indicated that the effects of long-term cold stress on P. argenteus , which is valuable for breeding cold-tolerant P. argenteus stocks for cultivation. • Long-term cold stress caused tissue damage of the gill, liver and muscle tissue of P. argenteus, antioxidant enzyme and Na-k ATPase activity in gill tissue were significantly increased. • The transcriptome profiling showed that a total of 618,097,404 reads of raw data were achieved, protein digestion and absorption, cardiac muscle contraction, were enrichment significantly. • Fifteen DEGs were selected from three tissues for real-time PCR (RT-qPCR) analysis, and the results consistent with transcriptome profiling. [ABSTRACT FROM AUTHOR]

The effects of different processing methods (Frying cooking, brining and boiling) on the proximate composition of fish species (Pampus argenteus) were investigated. The objective of this work is to know the best processing methods, the effect of processing on nutritional values of fish products. The result of the proximate composition of the fish species showed that the highest protein content (38.17%) was in P. argenteus processed with the frying process. The result of moisture content indicated that boiled samples were consistently the least (25.20%) while for fried sample had the highest moisture percentage. The lipid was reduced to the least value of 9.94% in the brined fish. In cooking, the important factors for consideration are moisture, lipids, and protein, though low moisture would ensure a fish product with extended shelf life. To have a longer shelf life, high protein is desirable, a low lipid is equally desirable as to reduce oxidation and rancidity in the samples which causes off-flavor and bad taste in fish products. In conclusion, all the processing methods are good and could extend the shelf life of the products with an exception of boiling method; they could keep the fish fillet free from spoilage and microorganisms attack for some period. This study showed that the proximate values obtained could be of help in choosing fish based on nutritional values.

The pharyngeal sac is a comparatively rare organ in the digestive tract among teleost fishes. However, our understanding of this remarkable organ in the silver pomfret (Pampus argenteus) is limited. In the present study, we examined the various morphological and histological characteristics of the pharyngeal sac using histochemical techniques and electron microscopy. The pharyngeal sac showed unique characteristics such as well-developed muscular walls, weakly keratinized epithelium, numerous goblet cells, and needle-like processes on the papillae. The porous cavity of the papillae contained numerous adipocytes and was tightly enveloped by type I collagen fibers. These structures might provide mechanical protection and excellent biomechanical properties for grinding and shredding prey. A comparison of gene expression levels between the pharyngeal sac and esophagus using RNA-seq showed that phenotype-associated genes (epithelial genes and muscle genes) were upregulated, whereas genes related to nutrient digestion and absorption were downregulated in the pharyngeal sac. These results support the role of the pharyngeal sac in shredding and predigesting food. Overall, these findings provide a clearer understanding of the pharyngeal sac morphology and explain the morphological adaptations of the digestive tract for feeding on gelatinous prey. To our knowledge, this is the first report on pharyngeal sac gene expression in P. argenteus.

Matrix metalloproteinase (MMP)-9 belongs to the zinc-dependent endopeptidase family, which is associated with important inflammatory processes and plays an important role in cell metabolism, embryonic development, and wound repair. The present study was performed using Pampus argenteus individuals fed with different feeds. The full-length cDNA of the MMP-9 gene was 2783 bp and encoded 681 amino acids. The amino acid sequence analysis of Pampus argenteus MMP-9 showed that it contained a highly conserved fibronectin type II domain and heme domain, and it was evolutionarily closely related to the MMP-9 of Seriola dumerili. Real-time PCR, western blotting, and enzyme activity assay were used to analyze the expression of MMP-9 in P. argenteus under different feeding conditions, in various tissues, and on different feeding days. The results showed that the expression of MMP-9 in group A (fed with jellyfish for the first 20 days) and B' group (fed with jellyfish for subsequent 15 days) was significantly higher than that in other groups (P < 0.05) and the expression in the kidney was significantly higher than that in other tissues (P < 0.05). The expression increased gradually with the increase in feeding time. The results suggest that MMP-9 expression is induced in P. argenteus fed with jellyfish and plays a very important role in the immune response of the body. [ABSTRACT FROM AUTHOR]

Silver pomfret (Pampus argenteus) performs a significant appetite for jellyfish, and amino acids are common components of the natural prey of fish, so we investigated the effect of aspartic acid, glycine and cysteine (high‐content amino acid in jellyfish) on olfactory‐related receptors regulating appetite in silver pomfret. The fish showed significant attractant responses to these amino acids in water, which were also observed to improve the ingestion rates of the fish. Next, we conducted transcriptomes of the olfactory epithelium (OE) and identified 34 olfactory‐related receptor genes were including olfactory receptors, trace amine‐associated receptors and vomeronasal receptors genes, and we examined these genes in the OE and appetite‐related genes (ghrelin and leptin in gut/stomach and neuropeptide Y, agouti‐related protein and proopiomelanocortin in brain) by qRT‐PCR. The olfactory‐related receptor genes significantly expressed in amino acid groups, and the expression level of appetite‐related genes was highest in aspartic acid group. Thus, olfactory‐related receptors induced by amino acids might regulate appetite in fish through the OE–brain–gut and stomach axis. Using these data, we identified some effective amino acid phagostimulants which could be supplied in silver pomfret diet, and the results improved our understanding of the mechanism of olfactory‐related receptors regulating appetite in fish. [ABSTRACT FROM AUTHOR]

Silver pomfret (Pampus argenteus) is an important economic fish for aquaculture industry in China and Southeast Asian countries.The relationship between twelve morphological traits of P. argenteus were studied at different growth stages [60-, 90-, 120-, and 360-days post hatching (dph)] by usingcorrelation, path analyses, and multiple linear regression tools. The results showed that coefficient of variation of the body weight and trunk length traits remained stable and at a high level across all age groups (all above 20%), while other traits were the opposite. The body length and tail length traits had great direct effect on the body weight of P. argenteus at the first three growth stages (60, 90, and 120 dph). However, body length and body height traits had great direct effect in 360 dph, and the direct effect coefficient of caudal length was negative, indicating that the trait had a negative effect on body weight. Multiple linear regression analysis between morphological traits and body weight indicated that R2 was greater than 0.84 across all age groups (P < 0.05).The optimal multiple linear regression equations, as determined with stepwise regression, were constructed with morphological traits as independent variables and body weight as dependent variables.These results elucidated the linear relationship between the body weight and various main morphological traits of P. argenteus at different growth stages. In actual production, during mass selection of P. argenteus with body weight as the main objective, the recommended as auxiliary selection traits were the body length, body height, tail length, and caudal length traits. These results can provide a reference basis for the measurement of target traits for the selective breeding of new varieties of P. argenteus. [ABSTRACT FROM AUTHOR]

Nocardia seriolae , a widespread opportunistic pathogen, has the ability to infect various economically farmed fishes, leading to prolonged disease courses and high mortality rates. In our current study, we focused on the silver pomfret (Pampus argenteus) and examined the liver, spleen, and kidney tissues at three specific N. seriolae infection phases: control (0 day), L group (infection for 5 days), and H group (infection for 15 days). Utilizing HE staining, we observed typical granulomatous nodules displaying stratified concentric layers, including caseous necrotic cells, epithelioid cells and multinucleated giant cells, fibroblasts and fibrocyte envelopes. The TUNEL assay revealed a significant presence of apoptotic cells concentrated within the renal nodules. Following the infection, there was a noticeable increase in AKP, ACP, and LZM levels in all tissues, while LPS exhibited a consistent decline. Through combined analysis of WGCNA and KEGG pathways derived from the tissue transcriptome, we identified several highly enriched pathways, such as the PI3K-Akt signaling pathway and p53 signaling pathway, in all three tissues. Key DEGs from these pathways underwent further investigation through RT-qPCR. In comparison to the control group, the L group exhibited up-regulation of genes associated with biosynthesis catabolism, whereas genes related to immune response, apoptosis, and ion transport displayed down-regulation. Interestingly, the H group showcased a stark reversal of this trend. To validate these DEGs expressions in vitro, we established a Pampus argenteus spleen cell line (PaS). By evaluating the invasion metrics of NS into PaS, we determined an optimal invasion threshold of 105 CFU/ml. The TUNEL assay demonstrated a notable presence of apoptotic signals in the 5 h and 7 h treatment groups. JC-1 assays indicated a gradual decline in membrane potential starting from the 3-h mark. As the duration of treatment increased, RT-qPCR and IHC findings highlighted an initial up-regulation followed by a subsequent down-regulation of genes associated with biosynthesis catabolism. In contrast, genes related to innate immunity displayed up-regulation, whereas genes related to adaptive immunity and ion transport exhibited an initial surge followed by a gradual decrease. Additionally, genes inhibiting apoptosis showed down-regulation. In conclusion, these findings provide valuable insights into the apoptosis mediated by N. seriolae in piscine hosts. These effects are potentially attributed to the increased expression of ion transport-related genes. Moreover, our study sheds light on the intricate molecular mechanisms underlying piscine immunological responses throughout the entire infection timeline, offering promising opportunities for disease control. • N. seriolae infection caused quintessential granulomatous nodules. • Many apoptotic cells centrally located within the renal nodules. • The weakening of metabolism declined acquired immunity after N. seriolae infection. • We constructed the spleen tissue cell line of silver pomfret. • The apoptosis caused by N. seriolae might be related to ion transport. [ABSTRACT FROM AUTHOR]

A 20 days feeding experiment and 15 days reversed feeding experiment were conducted to study the growth of Pampus argenteus juveniles under different feeding strategies. A total of 900 juveniles (an average ± SD, 5.88 ± 0.98 cm and 5.69 ± 0.64 g) were divided into three feeding groups and the experiments run in triplicate. Each experimental tank contained 1000 L of water and each group was fed to satiation four times a day. Three groups were constructed: group A (fed with 100% jellyfish), group B (fed with 100% Yubao 5# feed), and group C (fed with 50% jellyfish and 50% Yubao 5# mixed feed). The remaining 200 healthy individuals respectively in groups A and B were removed following the 20 days feeding experiment and subjected to 15 days of reverse feeding, resulting in group A' (fed with 100% Yubao 5# feed) and group B′ (fed with 100% jellyfish). Yubao 5# feed is 42% protein while live jellyfish larvae with a 1–2 cm umbrella diameter contain approximately 10% protein content. After 20 days, the results showed similar growth performance in terms of weight gain and specific growth rate (P > 0.05) for group A and B, indicating that the P. argenteus juveniles were able to survive on a jellyfish diet. However, the juveniles in group C showed significant (P < 0.05) weight gain and specific growth rate (8.96 ± 0.77 and 4.739 ± 0.572, respectively) over the same culture period. Serine protease (SP) was selected to study the detoxification mechanism of P. argenteus that were fed on jellyfish, and the SP enzyme activities, mRNA, and protein expression under different culture conditions were analyzed to illustrate the detoxification effect of SP protease on jellyfish toxin. The results showed that the highest SP enzyme activities occurred in the kidneys, liver, stomach, lateral capsules, caecum, and intestine (P < 0.05), with enzyme activity in the order group A > group C > group B, group A > A', and group B′ > B (P < 0.05). The highest enzyme activity of 188.91 UL /L was observed in group A when P. argenteus were fed jellyfish exclusively for 20 days (P < 0.05). The results indicate that jellyfish were the main contributors to the changes observed in the SP mRNA, protein, and enzyme activities. Our results indicate that P. argenteus juveniles can survive when feeding only on jellyfish and grow more rapidly when 50% jellyfish is added to the feed than when fed with jellyfish or Yubao 5# feed alone. SP enzymes, which are sensitive to jellyfish, play an important regulatory role in the digestion and decomposition of jellyfish by P. argenteus , and the kidneys are the most important organ for the detoxification and regulation of jellyfish toxin. • Pampus argenteus juveniles are able to maintain growth by feeding only on jellyfish. • Addition of jellyfish to feed significantly improves the growth of Pampus argenteus. • Serine protease in the kidney of Pampus argenteus plays a detoxifying role against jellyfish toxins. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms of lipid transport and metabolism in fish is crucial to enhance dietary lipid utilization. Here, fatty acid translocase (CD36) gene was characterized in silver pomfret (Pampus argenteus). The open reading frame of silver pomfret cd36 gene was 1395 bp, encoding 464 amino acids. The silver pomfret CD36 protein contained typical transmembrane regions and N-glycosylation modification sites, and was localized to the cytomembrane. The cd36 gene was ubiquitously expressed in all tested tissues, with the highest expression observed in brain tissue. In vivo , both fasting and short-term high-fat feeding could increase cd36 expression in intestinal tissue. In vitro , cd36 expression was induced by palmitic acid, oleic acid, linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid treatment in intestinal tissue. Furthermore, dual-luciferase reporter assay results indicated that peroxisome proliferator-activated receptor gamma (PPARγ) could enhance cd36 promoter activity, and the co-expression of cd36 and pparγ was observed in EPA-incubated intestine, suggesting that EPA may regulate the expression of cd36 via PPARγ to maintain the homeostasis of intestinal lipid metabolism in silver pomfret. These results highlighted the crucial role of CD36 in silver pomfret, and suggested that the cd36 expression may be regulated by PPARγ. This study could contribute to a greater understanding of lipid metabolism and the development of effective strategies for nutrient requirements in fish. [Display omitted] • CD36 was identified and characterized in silver pomfret. • Silver pomfret CD36 possessed typical transmembrane receptor characteristics. • Silver pomfret cd36 expression was regulated by nutritional status and LCFAs. • EPA might regulate Silver pomfret cd36 expression via PPARγ pathway. [ABSTRACT FROM AUTHOR]

Hepatic lipase (HL) is a key enzyme in endogenous triglyceride metabolism in blood circulation. The molecular mechanism and function of Pampus argenteusHL gene was investigated by cloning the full‐length cDNA of HL using PCR and RACE. The temporal and spatial expression characteristics of HL in different tissues and growth stages of P. argenteus and its localization in the liver were examined using real‐time PCR and in situ hybridization, and liver crude fat content was determined. The full‐length cDNA of P. argenteusHL gene was 1836 bp (GenBank No. KU497716); the 1485 bp ORF encodes 494 amino acids. P. argenteus HL protein had the highest homology with Siniperca chuatsi HL protein. In P. argenteus, HL was highly expressed in the liver and scarcely expressed in other tissues. HL expression in P. argenteus initially increased and then decreased at different growth stages (1–5, 5–15, 15–30, 30–50, 50–100 and >100 g), with the highest expression at 30–50 g fish weight, which was positively correlated with liver fat content. In situ hybridization showed that, in liver cells, HL was highly and weakly expressed in the cytoplasm and nucleolus, respectively, and not expressed in the nuclear interstitium. [ABSTRACT FROM AUTHOR]

• The rank of PTEs in fillet silver pomfret fish was Fe > Zn > Cr > Pb > Se > Cd > Ni > Cu > Total As > Co > methyl Hg. • The rank TTHQ in the adults consumers was Malaysia (2.500) > Bangladesh (0.886) > Iran (0.144) > China (0.045) > Pakistan (0.020) > India (0.015). • The rank TTHQ in the children consumers was Malaysia (11.790) > Bangladesh (4.146) > Iran (0.675) > China (0.206) > Pakistan (0.096) > India (0.077). The contamination of fish type products such as silver pomfret fish fillets by potentially toxic elements (PTEs) has raised global health concerns. Related studies regarding the concentration of PTEs in fillets of silver pomfret fish were retrieved among some international databases such as Scopus, PubMed and Embase between 1 January 1983 and 10 March 2020. The pooled (mean) concentration of PTEs in fillets of silver pomfret fish was meta-analyzed with the aid of a random-effect model (REM). Also, the non-carcinogenic risk was estimated via calculating the 95th percentile of the total target hazard quotient (TTHQ). The meta-analysis of 21 articles (containing 25 studies or data reports) indicated that the ranking of PTEs in fillets of silver pomfret fish was Fe (11,414.81 µg/kg wet weight, ww) > Zn (6055.72 µg/kg ww) > Cr (1825.79 µg/kg ww) > Pb (1486.44 µg/kg ww) > Se (1053.47 µg/kg ww) > Cd (992.50 µg/kg ww) > Ni (745.23 µg/kg ww) > Cu (669.71 µg/kg ww) > total As (408.24 µg/kg ww) > Co (87.03 µg/kg ww) > methyl Hg (46.58 µg/kg ww). The rank order of health risk assessment by country based on the TTHQ for adult consumers was Malaysia (2.500) > Bangladesh (0.886) > Iran (0.144) > China (0.045) > Pakistan (0.020) > India (0.015), while the corresponding values for child consumers was Malaysia (11.790) > Bangladesh (4.146) > Iran (0.675) > China (0.206) > Pakistan (0.096) > India (0.077). The adult consumers in Malaysia and children in Malaysia and Bangladesh were at considerable non-carcinogenic risk. Therefore, following the recommended control plans in order to reduce the health risk associated with the ingestion of PTEs via consumption of silver pomfret fish fillets is crucial. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The silver pomfret (Pampus argenteus) is one of the most commercially important marine fish species in the Bay of Bengal, Indian Ocean. However, detailed information on the reproductive biology of silver pomfret is limited for the Bay of Bengal, Bangladesh. To understand their reproductive biology, especially the gonadal developmental cycle and spawning season, a total of 373 individuals were collected monthly from February 2016 to January 2018 and examined. The total length (TL) and weight (TW) of P. argenteus ranged from 18.82–35.73 cm and 89.26–617.60 g, respectively. The highest gonadosomatic index (GSI) values were observed from April–June with a second (smaller) peak in October. The highest oocyte diameter was observed in May (630.50 ± 96.70 μm), when the fish reached full maturity, and the lowest was observed in July (35.10 ± 7.12 μm), when new eggs began their development for the next spawning season. The maximum number of eggs in the ovary were found in the yolk granule stage in May with a number of post-ovulatory follicles, which indicated that the ovaries developed to a peak leading up to the spawning season. A number of spermatids were also seen in males in April–June along with females. From these detailed observations, it may be concluded that P. argenteus shows two spawning peaks, in May–June and October. This observation will be helpful for the artificial breeding, sustainable management and conservation of this species in the study area. [ABSTRACT FROM AUTHOR]

Abstract Pampus argenteus (Perciformes: Stromateidae) is widely distributed along the coast of China, Indian Ocean, Arabian Gulf and North Sea. Due to overfishing and environmental degradation, its resources reduced year after year. Thus, new management strategies are urgently needed for the sustainable growth and utilization of this species. Characterization of the genetic variation of this fish species is essential for conserving the genetic resource and restraining the population decline. Therefore, it is necessary to have a clear understanding of the intraspecific genetic diversity and population structure of the species. In this study, we assess the genetic diversity and population structure of P. argenteus by using microsatellites. We genotyped 240 P. argenteus individuals from eight wild populations collected from Shidao (SD), Lianyungang (LYG), Lvsi (LS), Zhoushan (ZS), Dongtou (DT), Xiapu (XP), Haikou (HK), and Beibuwan (BBW) along the coast of China using fifteen polymorphic microsatellites. A total of 139 alleles were determined at 15 loci across the eight populations, and a relatively high level of genetic diversity was observed, with observed heterozygosity (Ho) and expected heterozygosity (He) ranging from 0.100 to 1.000, and from 0.669 to 0.934 per locus-location combination, respectively. LS had the highest average allele (number of alleles, A=15.200), and HK the lowest (A=13.000). Hos of P. argenteus are less than Hes, indicating lack of heterozygote within populations. Analysis of molecular variance (AMOVA) showed that most variation (95.66%) occurred within populations, suggesting that this is the main source of total variance. This study will provide useful information for conservation and sustainable exploitation of this important fishery resource.

Gut microorganisms play an important role in host health and have susceptibility to diseases, undergoing a distinct transformation at early stages of development. This study aimed to determine the regulation of gut microorganism development from fertilized eggs to 150 DAH (days after hatching) and the differences between flatulent and healthy silver pomfret (Pampus argenteus). High‐throughput sequencing was used to analyze the diversity and relative abundance of microorganisms. PICRUSt was used to predict functional alterations of dominant microorganisms. The results showed that from all 42 samples, a total of 3,746,895 reads were obtained, representing 6,081 operational taxonomic units (OTUs). Top 3 phyla were Proteobacteria, Firmicutes and Bacteroidetes. From 0 to 32 DAH, the relative abundance of Proteobacteria continuously increased and peaked at 94.99%. After that, the abundance of Proteobacteria decreased, but Bacteroidetes and Firmicutes increased instead. Alpha diversity is the lowest at 32 DAH, the difference is significant compared with others, p <.05. Comparing flatulent fish with healthy fish, the former has more specific OTUs, higher diversity and abundance. There were four genera Ethanoligenens, Methanobacterium, Caproiciproducens and Leptolinea that only obtained from the flatulent samples, but almost none in the healthy samples. All of these four genera are directly or indirectly involved in gas metabolism. This study enriched the basic research of silver pomfret, for the first time, focused on flatulent individuals which would provide a theoretical basis for the subsequent breeding. [ABSTRACT FROM AUTHOR]

Salinity is a major ecological factor in the marine environment, and extremely important for the survival, development, and growth of fish. In this study, gill transcriptomes were examined by high-throughput sequencing at three different salinities (12 ppt as low salinity, 22 ppt as control salinity, and 32 ppt as high salinity) in an importantly economical fish silvery pomfret. A total of 187 genes were differentially expressed, including 111 up-regulated and 76 down-regulated transcripts in low-salinity treatment group and 107 genes differentially expressed, including 74 up-regulated and 33 down-regulated transcripts in high-salinity treatment group compared with the control group, respectively. Some pathways including NOD-like receptor signaling pathway, cytokine-cytokine receptor interaction, Toll-like receptor pathway, cardiac muscle contraction, and vascular smooth muscle contraction were significantly enriched. qPCR analysis further confirmed that mRNA expression levels of immune (HSP90A, IL-1β, TNFα, TLR2, IP-10, MIG, CCL19, and IL-11) and ion transport–related genes (WNK2, NPY2R, CFTR, and SLC4A2) significantly changed under salinity stress. Low salinity stress caused more intensive expression changes of immune-related genes than high salinity. These results imply that salinity stress may affect immune function in addition to regulating osmotic pressure in silvery pomfret. [ABSTRACT FROM AUTHOR]

The effects of different processing methods (Frying cooking, brining and boiling) on the proximate composition of fish species (Pampus argenteus) were investigated. The objective of this work is to know the best processing methods, the effect of processing on nutritional values of fish products. The result of the proximate composition of the fish species showed that the highest protein content (38.17%) was in P. argenteus processed with the frying process. The result of moisture content indicated that boiled samples were consistently the least (25.20%) while for fried sample had the highest moisture percentage. The lipid was reduced to the least value of 9.94% in the brined fish. In cooking, the important factors for consideration are moisture, lipids, and protein, though low moisture would ensure a fish product with extended shelf life. To have a longer shelf life, high protein is desirable, a low lipid is equally desirable as to reduce oxidation and rancidity in the samples which causes off-flavor and bad taste in fish products. In conclusion, all the processing methods are good and could extend the shelf life of the products with an exception of boiling method; they could keep the fish fillet free from spoilage and microorganisms attack for some period. This study showed that the proximate values obtained could be of help in choosing fish based on nutritional values. [ABSTRACT FROM AUTHOR]

Pampus argenteus (Perciformes: Stromateidae) is an economically important benthopelagic fish, which is widely distributed along the coast of China, Indian Ocean, Arabian Gulf and North Sea. To benefit population genetics studies and resource management, 26 pairs of novel microsatellite loci of P. argenteus were isolated using combined biotin capture method. These loci all included di-nucleotide repeat motifs. All markers showed polymorphism when assessed in 30 individuals from Xiapu population. The number of alleles per locus (NA) ranged from 4 to 22, and polymorphism information content (PICs) were from 0.565 to 0.924. Mean values of observed (HO) and expected (HE) heterozygosities ranged from 0.267 to 1.000 and from 0.633 to 0.929, respectively. Cross-species amplification showed that 22 microsatellite markers were successfully amplified in 30 individuals of P. minor, a closely related species of P. argenteus, and indicated clearly polymorphisms. The markers developed in this study will provide a useful tool for investigating the genetic structure, gene flow, and mating system of P. argenteus and the closely related species. They will also facilitate study on their evolutionary responses to the ongoing coastal systems change. [ABSTRACT FROM AUTHOR]

Silver pomfret fish (Stromateidae) is a family of Perciformes order. One species of this family is Pampus argenteus known as silver pomfret and lives in different parts of the Persian Gulf and Gulf of Oman. Therefore, the genetic relationship between its populations is so important. In this study, eight samples of Pampus argenteus were collected from four locations involved: Emam Khomeyni, Bushehr and Bandar Abbas in Persian Gulf and Chabahar in Gulf of Oman. Cytochrome b gene and D-loop region of mitochondrial DNA on these samples are analyzed. These genes are carried out using PCR with specific mtDNA primers and sequenced. Then, the evolutionary history was inferred by using the maximum-likelihood method. Evolutionary analyses were conducted in MEGA7. According to the phylogenetic trees, with translocations in Persian Gulf to Gulf of Oman, similarity decreases slowly. Chabahar1 sample in phylogenetic tree of cytochrome b is phylogenetically near China Sea samples. The reason may be migration from ocean to gulf throughout the centuries and Chabahar is in Gulf of Oman and locationally near the Arabian Sea and Indian Ocean. In D-loop region, results are similar to cytochrome b excepting one sample (Emam Khomeyni1). D-Loop in samples shows modification more than cytochrome b for the reason absence of protein product.

A cell line (PaF) derived from the fin tissue of silver pomfret (Pampus argenteus) was established and characterized in this study. The cell line has been subcultured for more than 50 times in Dulbecco's modified Eagle's medium (DMEM) containing 15% foetal bovine serum (FBS) since the initial primary culture. PaF cells grew well at temperatures from 24°C to 28°C in DMEM supplemented with 15% FBS. Partial amplification and sequence analysis of the cytochrome B gene indicated that PaF originated from silver pomfret. Cytogenetic analysis demonstrated that the modal chromosome number was 48. A significant cytopathic effect was observed in PaF cells during viral haemorrhagic septicaemia virus (VHSV) infection, and the VHSV replication was confirmed by qRT‐PCR and viral titre assays. In contrast, PaF cells were resistant to red‐spotted grouper nervous necrosis virus infection. Moreover, PaF cells could respond to VHSV and lipopolysaccharide treatments, as indicated by the expression of immune‐related genes, TLR5 and TLR9. In conclusion, the establishment of PaF cell line will provide an appropriate in vitro tool for the study of mechanisms of pathogen–silver pomfret interaction. [ABSTRACT FROM AUTHOR]

Pampus argenteus is an aquatic cold-blooded animal, and its growth and survival are greatly affected by ambient temperature. During aquaculture, a sudden change in water temperature may be caused by climate change or other human factors, resulting in acute temperature stress. In this study, de novo transcriptome sequencing technology was used to analyze changes in the gene expressions in the liver of P. argenteus under temperature stress to understand the mechanisms of temperature regulation in P. argenteus. The results showed that 72447398, 69534310, 63698204, 78876728 and 53969050 clean reads were obtained from four cDNA libraries (A: 27°C (control group), B: 22°C and 6 h, C: 32°C and 6 h, D: 22°C and 12 h, E: 32°C and 12 h) of the P. argenteus by Illumina sequencing technology. In A\B, A\C, A\D and A\E pairwise comparison, 353, 431, 1303 and 343 differentially expressed genes (DEGs) were detected, respectively. Of these genes, 67 genes were identified among all the pairwise comparisons as the common DEGs. Four genes related to metabolic adaption to temperature were randomly selected to validate the DEGs results by real time PCR. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated some vital genes and pathways associated with metabolism in response to temperature challenge. These results will help us to understand the molecular mechanism underlying temperature regulation in P. argenteus and provide a theoretical basis for the study of related molecular mechanisms in fish under temperature stress. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the illegal Silver pomfret catch by fixed gill-nets in Hormozgan inshore waters (Qeshm Island). Sampling was performed in Bandar Laft estuaries through three fishing boats between April to July 2015. The fishing gears were the nylon mono-filament fixed gill-net with 6.5 cm mesh size (bar), 200 m length and 8-10 m height. The non-parametric bootstrap method was utilized to estimate the average catch rate (± Confidence interval) of commercial fish caught. After forty-eight landings, the catch composition included 14 teleost fish species and 1 invertebrate. The catch composition by weight also included 59.57 % target species (P. argenteus) and 40.43 % incidental catch. For incidental fish caught, M. cephalus and P. sextarius with 39.58 % and 6.83 % had highest and lowest occurrence and L. johnii with 4.57 % had highest weight percentage. The catch rate (kg.boat-1.day-1) of P. argenteus was calculated between 9.125 and 16.941. Using Monte Carlo procedure, annual illegal Silver pomfret catch was estimated between 265.690 to 303.701 tonnes (α=0.05).