Search Results (12)

Food enrichment represents a novel feeding strategy for aquaculture. In the current study, juvenile Nibea albiflora (average weight 29.65 ± 0.13 g) were used and three feeding regimes (A—commercial diet; B—a diet comprising 90% commercial feed and 10% ice-fresh Palaemon gravieri; C—a diet consisting of 90% commercial diet, 5% ice-fresh Palaemon gravieri and 5% live Perinereis nuntia; named control group, Group 1, and Group 2) with comparable nutrient compositions: were designed to establish the food enrichment model and explore the effects of such feeding strategies on the fish. The cultivation period was 60 days, and the physiological, pathological, and RNA-seq analyses were performed to evaluate the effects. The results showed that the food enrichment feeding strategy significantly enhanced fish growth performance, immunity, and stress resistance without increasing the unit production cost (UPC). Furthermore, the tri-combined food feeding (C) was better than the two-combined food feeding (B). Liver transcriptomic analysis revealed that, in the comparison between the control group and Group 1, the up-regulated genes (alox15b, gng7, hif1a, ppara, and pla2g) and down-regulated genes (ins, gck, il4i1) influenced fish physiology and further improved growth. Similar to the comparison between the control group and Group 2, the major functional genes included ugt, nlrp3, mx1, col1a, gst (up-regulated), and map2k1, myc, mmp9, wnt7, socs3 (down-regulated) that participated in regulating the body growth, immunity, and stress resistance. The up-regulated genes (ins, mhc2, foxo3, ppara, and mx1) alongside the down-regulated genes (egfr, fos, cyc, myc, and mmp9) probably contributed to the enhanced efficacy of the tri-combined food feeding compared to the two-combined food feeding. In summary, this study demonstrates the beneficial effects of such a food enrichment model on the fish and provides empirical evidence supporting the implementation of the feeding strategies in the healthy culturing of the fish. Full article

The cryopreservation of ovarian tissues from fish has recently been carried out for several endangered and commercially valuable species. However, previous studies in this context have focused on the cryopreservation of immature ovaries—mainly through slow freezing and vitrification—which requires specialized freezing equipment or higher cryoprotectant concentrations to keep cell viability. Therefore, the aim of this study was to explore a convenient, rapid, efficient and less toxic method for the cryopreservation of ovaries at the stage of vitellogenesis from yellow drum (Nibea albiflora), an economically important marine fish. The ovaries at the stage of vitellogenesis were isolated and cut into blocks of approximately 1 cm³, then cryopreserved with 15% propylene glycol (PG), fetal bovine serum (FBS) and 0.2 M trehalose as cryoprotectants. Finally, the samples were treated using three different freezing procedures, including a −80 °C refrigerator, liquid nitrogen, and their combination. After 7 days, the tissues were thawed and digested, and the cell survival rates and gene expression levels were detected using cell viability assay kits and qRT-PCR, respectively. The results of the viability assay showed that the procedure of ovarian tissue storage at −80 °C in a refrigerator for 1 h, followed by transfer to liquid nitrogen, resulted in the highest cell survival rate (>90%). Furthermore, the germ cells at various phases were of normal size; presented a full, smooth surface and regular shape; and did not show any signs of cell rupture, atrophy, depression, granulation or cavitation. Furthermore, the qRT-PCR results revealed that genes related to reproductive development, such as vasa, foxl2, zp3 and gsdf, were all down-regulated under the optimal protocol, while the expression of the nanos2 gene (which is specifically distributed in oogonia) maintained a higher level, similar to that in the control group. This indicated that the viability of germ stem cells (oogonia) was not weakened after freezing and that oogonia could be isolated from the cryopreserved ovaries for germ cell transplantation. The present study successfully establishes an optimal cryopreservation protocol for ovarian tissues from Nibea albiflora, providing reference for the preservation of ovaries at the stage of vitellogenesis from other species. Full article

The inherent deficiency of phospholipids in Artemia limits its nutritional value as live prey for marine fish larvae. In our previous study, we optimized a phospholipid enrichment method by incubating Artemia nauplii with 10 g of soybean lecithin per m³ of seawater for 12 h, significantly enhancing their phospholipid content. Purpose: The present study evaluated the impact of this enrichment on yellow drum (Nibea albiflora) larvae, focusing on growth performance, intestinal morphology, body composition, weaning success, and desiccation stress resistance. Methods: The larvae (12 days post-hatching, dph) were fed either soybean lecithin-enriched (SL group) or newly hatched (NH group) Artemia nauplii for 10 days. Results: By the end of the experiment, the SL group exhibited a markedly greater body weight and standard length compared to the NH group (p < 0.05). This growth improvement was due to enhanced intestinal morphology, characterized by a significantly higher mucosal fold height, microvillus density, and microvillus length (p < 0.05). Intestinal RNA sequencing identified 160 upregulated and 447 downregulated differentially expressed genes (DEGs) in the SL group compared to the NH group. Soybean lecithin enrichment reduced the expression of lipogenesis-related genes (fasn, scd, elovl1) while upregulating lipid catabolism genes (ppara, cpt1, cpt2), indicating increased lipid breakdown and energy production. After a 5-day weaning period onto a commercial microdiet, the SL group continued to show significantly superior growth performance. In an afterward desiccation stress test, larvae from the SL group demonstrated significantly higher survival rates, potentially due to the decreased expression of intestinal cytokine genes (ccl13, mhc1, mhc2) observed in the RNA-seq analysis. Conclusions: This study highlights that feeding soybean lecithin-enriched Artemia nauplii enhances growth performance and desiccation stress in yellow drum larvae by promoting lipid catabolism, improving intestinal structure, and regulating immune responses. Full article

Sphingosine kinases (SPHKs) are essential enzymes that catalyze the phosphorylation of sphingosine to produce sphingosine-1-phosphate (S1P), which plays pivotal roles in inflammation and immune regulation. In this study, genome-wide association analysis (GWAS) identified the Ydsphk1 gene as closely associated with the resistance of yellow drum (Nibea albiflora) to Vibrio harveyi. Structural prediction showed that YDSPHK1 contains a typical diacylglycerol kinase catalytic (DAGKc) domain (154–291 aa). By constructing and transfecting Ydsphk1 expression plasmids into yellow drum kidney cells, we found that YDSPHK1 is localized in the cytoplasm. Subsequent RNA-Seq analysis of an overexpression plasmid identified 25 differentially expressed genes (DEGs), including 13 upregulated and 12 downregulated. Notably, nsun5 and hsp90aa1 were significantly upregulated, while Nfkbia and hmox1 were downregulated. Promoter analysis indicated that the core regulatory regions of Ydsphk1 are located between −1931~−1679 bp and −419~+92 bp, with two predicted TFAP2A binding sites in the −419~+92 bp region. Further studies demonstrated that varying concentrations of TFAP2A significantly reduced Ydsphk1 promoter activity. These findings underscore the pivotal role of Ydsphk1 in regulating immune responses in yellow drum, particularly through its impact on key immune-related genes and pathways such as NF-κB signaling and ferroptosis. The identification of Ydsphk1 as a mediator of immune regulation provides valuable insights into the molecular mechanisms of immune defense and highlights its potential as a target for enhancing pathogen resistance in aquaculture practices. This study lays a strong foundation for future research aimed at developing innovative strategies for disease management in aquaculture species. Full article

To describe the species composition of fish larvae and juveniles in the Nanji Islands, monthly collection was conducted at 12 stations around the Nanji Islands from March 2023 to February 2024 by using horizontal tow at the surface layer. The fish larvae and juveniles were collected by a larva net (1.3 m mouth diameter, 0.5 mm mesh aperture). A total of 6446 fish larvae and juveniles were collected, belonging to 59 species and 54 genera in 11 families. Most of them were preflexion larvae (93.31%). Gobiidae, with eight species, was the most diverse family. Based on the index of relative importance (IRI) result, the dominant species was Sebastiscus marmoratus (Cuvier, 1829), accounting for 84.52% of the total number of samples collected. The common species were Stolephorus commersonii Lacepède, 1803; Omobranchus elegans (Steindachner, 1876); Nibea albiflora (Richardson, 1846); Parablennius yatabei (Jordan & Snyder, 1900); Lateolabrax maculatus (McClelland, 1844); and Odontamblyopus lacepediiand (Temminck & Schlegel, 1845). Other species were all rare species. The highest species number was in September (18 species), and the highest density was in December. Only one fish larva was collected in April. Pielou’s evenness index was highest in November, while Margalef’s richness index and Shannon–Wiener diversity were highest in September. The result of cluster analysis showed that the 11 months (except April) could be divided into four groups. The species number, density, and three diversity indexes showed no significant correlation with temperature and salinity. Full article

In this study, twelve polymorphic microsatellite loci were screened to evaluate the genetic diversity of five yellow drum (Nibea albiflora) populations in the Zhoushan Sea region of the East China Sea, including one wild population (WP), one artificially propagated population (common population, CP), and three breeding populations (parent population, F4; all-female population, AF; and neo-male population, NeoG). The results of genetic diversity analyses showed that all five yellow drum populations had relatively high genetic diversity, with the highest in WP and the lowest in NeoG. Genetic structure analyses showed that the level of genetic differentiation among populations was low, with that between CP and F4 being the largest, whereas that between CP and WP was the smallest. Mutation–drift equilibrium analysis showed that the five populations likely did not experience a recent bottleneck. Our results suggest the CP population was the most suitable for large-scale release for stock enhancement, and precautionary measures shall be taken for the AF population before it is used for cage culture to avoid potential genetic concerns of the wild population. Nevertheless, further genetic diversity monitoring is needed to evaluate genetic effects and avoid the negative impact of excessive genetic differentiation between breeding and wild populations. Full article

The yellow drum (Nibea albiflora) is a marine teleost fish with strong disease resistance, yet the understanding of its immune response and key functional genes is fragmented. Here, RNA-Seq was used to investigate the regulation pathways and genes involved in the immune response to infection with lipopolysaccharide (LPS) and polyinosinic-polycytidylic acid (poly (I:C)) on the spleen of the yellow drum. There were fewer differentially expressed genes (DEGs) in the LPS-infected treatment group at either 6 or 48 h. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that these DEGs were mainly significantly enriched in c5-branching dibasic acid metabolic and complement and coagulation cascades pathways. The yellow drum responded more strongly to poly (I:C) infection, with 185 and 521 DEGs obtained under 6 and 48 h treatments, respectively. These DEGs were significantly enriched in the Toll-like receptor signaling pathway, RIG-I-like receptor signaling pathway, Jak-STAT signaling pathway, NOD-like signaling pathway, and cytokine–cytokine receptor interaction. The key functional genes in these pathways played important roles in the immune response and maintenance of immune system homeostasis in the yellow drum. Weighted gene co-expression network analysis (WGCNA) revealed several important hub genes. Although the functions of some genes have not been confirmed, our study still provides significant information for further investigation of the immune system of the yellow drum. Full article

To address the issue of minimum mesh size regulations of the stow net fishery for croaker species, we tested and compared the size selectivity and exploitation pattern for diamond- and square-mesh codends with mesh sizes 35, 45 and 55 mm for little yellow croaker (Larimichthys polyactis), silver croaker (Pennahia argentata), and flower croaker (Nibea albiflora) in the Yellow Sea, China. Our results showed that the legal codend (35 mm diamond-mesh) was inadequate to protect the juvenile croaker species because more than 75% of undersized individuals were retained, and the discard ratios were as high as approximately 60%. Irrespective of mesh shape, increasing the codend mesh sizes could significantly improve the size selectivity and exploitation pattern of croaker species. Between codends with the same mesh size, the square-mesh codends had higher size selectivity than diamond-mesh codends. Based on results, the 55 mm square-mesh codend was recommended for rational exploitation of croaker stocks. This study can provide feasibility and insight for the enforcement and reform of management strategies for sustainable fishing in Chinese stow net fisheries. Full article

Galectins are proteins that are involved in the innate immune response against pathogenic microorganisms. In the present study, the gene expression pattern of galectin-1 (named as NaGal-1) and its function in mediating the defense response to bacterial attack were investigated. The tertiary structure of NaGal-1 protein consists of homodimers and each subunit has one carbohydrate recognition domain. Quantitative RT-PCR analysis indicated that NaGal-1 was ubiquitously distributed in all the detected tissues and highly expressed in the swim-bladder of Nibea albiflora, and its expression could be upregulated by the pathogenic Vibrio harveyi attack in the brain. Expression of NaGal-1 protein in HEK 293T cells was distributed in the cytoplasm as well as in the nucleus. The recombinant NaGal-1 protein by prokaryotic expression could agglutinate red blood cells from rabbit, Larimichthys crocea, and N. albiflora. The agglutination of N. albiflora red blood cells by the recombinant NaGal-1 protein was inhibited by peptidoglycan, lactose, D-galactose, and lipopolysaccharide in certain concentrations. In addition, the recombinant NaGal-1 protein agglutinated and killed some gram-negative bacteria including Edwardsiella tarda, Escherichia coli, Photobacterium phosphoreum, Aeromonas hydrophila, Pseudomonas aeruginosa, and Aeromonas veronii. These results set the stage for further studies of NaGal-1 protein in the innate immunity of N. albiflora. Full article

Uncertainty and controversy exist in the phylogenetic status of the Sciaenidae family because of the limited genetic data availability. In this study, a data set of 69,098 bp, covering 309 shared orthologous genes, was extracted from 18 genomes and 5 transcriptomes of 12 species belonging to the Sciaenidae family and used for phylogenetic analysis. The maximum likelihood (ML) and Bayesian approach (BA) methods were used to reconstruct the phylogenetic trees. The resolved ML and BA trees showed similar topology, thus revealing two major evolutionary lineages within the Sciaenidae family, namely, Western Atlantic (WA) and Eastern Atlantic–Indo–West Pacific (EIP). The WA group included four species belonging to four genera: Cynoscion nebulosus, Equetus punctatus, Sciaenops ocellatus, and Micropogonias undulatus. Meanwhile, the EIP group formed one monophyletic clade, harboring eight species (Argyrosomus regius, A. japonicus, Pennahia anea, Nibea albiflora, Miichthys miiuy, Collichthys lucidus, Larimichthys polyactis, and L. crocea) from six genera. Our results indicated that the Western Atlantic (WA) group was more ancient in the studied species, while the Eastern Atlantic–Indo–West Pacific (EIP) group was a younger group. Within the studied species, the genera Collichthys and Larmichthys were the youngest lineages, and we do not suggest that Collichthys and Larmichthys should be considered as one genus. However, the origin of the Sciaenidae family and problems concerning the basal genus were not resolved because of the lack of genomes. Therefore, further sampling and sequencing efforts are needed. Full article

Phosphoribosyl pyrophosphate synthetases (EC 2.7.6.1) are key enzymes in the biological synthesis of phosphoribosyl pyrophosphate and are involved in diverse developmental processes. In our previous study, the PRPS1 gene was discovered as a key disease-resistance candidate gene in yellow drum, Nibea albiflora, in response to the infection of Vibrio harveyi, through genome-wide association analysis. This study mainly focused on the characteristics and its roles in immune responses of the PRPS1 gene in yellow drum. In the present study, the NaPRPS1 gene was cloned from yellow drum, encoding a protein of 320 amino acids. Bioinformatic analysis showed that NaPRPS1 was highly conserved during evolution. Quantitative RT-PCR demonstrated that NaPRPS1 was highly expressed in the head-kidney and brain, and its transcription and translation were significantly activated by V. harveyi infection examined by RT-qPCR and immunohistochemistry analysis, respectively. Subcellular localization revealed that NaPRPS1 was localized in cytoplasm. In addition, semi-in vivo pull-down assay coupled with mass spectrometry identified myeloid differentiation factor 88 (MyD88) as an NaPRPS1-interacting patterner, and their interaction was further supported by reciprocal pull-down assay and co-immunoprecipitation. The inducible expression of MyD88 by V. harveyi suggested that the linker molecule MyD88 in innate immune response may play together with NaPRPS1 to coordinate the immune signaling in yellow drum in response to the pathogenic infection. We provide new insights into important functions of PRPS1, especially PRPS1 in the innate immunity of teleost fishes, which will benefit the development of marine fish aquaculture. Full article

The yellow drum (Nibea albiflora) is an important marine economic fish that is widely distributed in the coastal waters of the Northwest Pacific. In order to understand the molecular regulatory mechanism of the yellow drum under salinity stress, in the present study, transcriptome analysis was performed under gradients with six salinities (10, 15, 20, 25, 30, and 35 psu). Compared to 25 psu, 907, 1109, 1309, 18, and 243 differentially expressed genes (DEGs) were obtained under 10, 15, 20, 30, and 35 psu salinities, respectively. The differential gene expression was further validated by quantitative real-time PCR (qPCR). The results of the tendency analysis showed that all DEGs of the yellow drum under salinity fluctuation were mainly divided into three expression trends. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that the PI3K-Akt signaling pathway, Jak-STAT signaling pathway as well as the glutathione metabolism and steroid biosynthesis pathways may be the key pathways for the salinity adaptive regulation mechanism of the yellow drum. G protein-coupled receptors (GPCRs), the solute carrier family (SLC), the transient receptor potential cation channel subfamily V member 6 (TRPV6), isocitrate dehydrogenase (IDH1), and fructose-bisphosphate aldolase C-B (ALDOCB) may be the key genes in the response of the yellow drum to salinity stress. This study explored the transcriptional patterns of the yellow drum under salinity stress and provided fundamental information for the study of salinity adaptability in this species. Full article