Search Results (28)

To elucidate the interactions among fatty acid metabolism, immune status, and gut microbiota, both cultured and wild Coilia nasus from the Yangtze River were examined in China. The results demonstrated that wild C. nasus exhibited markedly higher lipid and docosahexaenoic acid (DHA) contents, a greater ratio of total ω-3 PUFAs to total ω-6 PUFAs, and more active antioxidant enzymes compared to cultured C. nasus. However, the shear force, water-holding capacity, and total n-6 PUFA content were lower in wild C. nasus. Transcriptome analysis revealed distinct gene expression patterns: wild C. nasus upregulated immune-related genes, while cultured C. nasus downregulated genes related to fatty acid metabolism. Significant differences were observed in alpha and beta diversity between cultured and wild groups. LEfSe analysis identified Clostridium_T, Escherichia, and Glutamicibacter as biomarkers for cultured C. nasus, while eight genera, including Pseudomonas_E and Sphingomonas_L, were predominant in wild C. nasus. Modular analysis identified five modules linked to immune functions and fatty acid metabolism. Clostridium_T, Sphingomonas_L, and Pseudomonas_E were dominant in the first two modules, with Pseudomonas_E and Clostridium_T as key regulators of fatty acid metabolism and immune processes. These differences, likely due to gut microbiota variations, provide insights for C. nasus nutritional studies. Full article

Transport stress in aquaculture poses significant challenges to fish health by inducing oxidative stress and intestinal damage. This study investigated the effects of transport stress on intestinal microbiota, host gene regulation, and metabolic responses in Coilia nasus. The fish were subjected to simulated transport conditions, followed by an analysis of their intestinal antioxidant capacity, inflammatory factors, transcriptome sequencing, metagenomic profiling, and metabolomic assays. The results revealed that transport stress significantly suppressed antioxidant enzyme activities (e.g., catalase, superoxide dismutase, glutathione peroxidase) and elevated oxidative damage (malondialdehyde, lipid peroxidation) alongside upregulating pro-inflammatory cytokines. The transcriptomic analysis identified differentially expressed genes enriched in the lipid metabolism and ferroptosis pathways, with the increased lipid peroxidation and iron overload activating ferroptosis. The metagenomic data showed an altered gut microbiota composition, including increased Aeromonas and reduced beneficial metabolites (e.g., propionic acid, bile acids). Correlation analyses linked the microbial shifts and metabolite changes to ferroptosis and barrier dysfunction. These findings demonstrate that transport stress disrupts intestinal redox balance, induces ferroptosis, and reshapes gut microbiota, collectively compromising intestinal integrity and health in C. nasus. Full article

The expansion of intensive aquaculture has heightened metabolic dysregulation in fish caused by high-glucose and high-lipid (HG-HL) diets, contributing to growth retardation and hepatic pathologies. Using Coilia nasus hepatocytes, this study investigated the regulatory effects of short-chain fatty acids (SCFAs) on glucose-lipid metabolism. In vitro HG-HL exposure elevated intracellular glucose, triglycerides (TG), and cholesterol; suppressed catalase (CAT) and superoxide dismutase (SOD); and dysregulated metabolic genes (upregulated phosphoenolpyruvate carboxykinase and acetyl-CoA carboxylase; downregulated glucokinase and hormone-sensitive lipase). Co-treatment with acetate and propionate reversed these anomalies, reducing TG and cholesterol, restoring antioxidant capacity (SOD and CAT), and normalizing gene expression patterns. Molecular docking suggested potential binding interactions between SCFAs and free fatty acid receptor (FFAR2/3). This study provided initial evidence suggesting SCFAs might attenuate HG-HL-induced metabolic stress in a teleost model, potentially involving FFAR-related pathways and AMPK-associated responses. The findings contribute to understanding SCFA-mediated metabolic regulation in fish, offering preliminary support for developing dietary interventions to manage aquacultural metabolic syndromes. Full article

High-fat diets (HFDs) usually trigger disruptions in lipid metabolic processes and immune suppression in fish. As an eco-friendly and potent additive, the inclusion of probiotics in fish diets ameliorates dysregulations in lipid metabolism, mitigates oxidative stress, and reduces inflammatory reactions triggered by HFDs. However, little current research has focused on the improvement of the hazards of HFDs in fish by probiotics. Therefore, we employed 4-dimensional data-independent (4D-DIA) proteomic analysis to investigate the mechanism of the protective impact of probiotics against HFD-induced hepatic injury in Coilia nasus between the HFD group and the probiotic supplementation in HFD (PHFD) group. Additionally, lipid accumulation and antioxidant indicators in the liver were also measured via Oil Red O staining and activity detection. Administration of probiotics markedly attenuated the hepatic concentrations of triglycerides (TG), cholesterol (CHO), and low-density lipoprotein cholesterol (LDL-C) in C. nasus subjected to HFDs. Furthermore, it significantly upregulated the expression of the differentially expressed proteins (DEPs) implicated in cholesterol metabolism and fatty acid oxidation, while concurrently downregulating the DEPs associated with fatty acid synthesis. Additionally, probiotic supplementation significantly reduced the aspartate aminotransferase (AST), alanine aminotransferase (ALT), and malondialdehyde (MDA) levels induced by HFDs. It also upregulated the activities of catalase (CAT) and superoxide dismutase (SOD). Probiotic supplementation significantly upregulated the DEPs related to antioxidants, while significantly downregulating the DEPs associated with inflammatory responses and autophagy. These findings suggested that probiotics ameliorated HFD-induced hepatic lipid accumulation in C. nasus by enhancing cholesterol metabolism and fatty acid oxidation, concomitantly with the suppression of fatty acid synthesis pathways. Additionally, probiotics protected against HFD-induced hepatic injury by enhancing antioxidant defenses and suppressing inflammation in C. nasus. Full article

X-ray electron probe microanalyzer technology was used to study the microchemistry and habitat history of Coilia nasus collected from the Dawanzhou section of the Yangtze River between May and June 2023. The Sr/Ca ratio from the otolith core to the otolith diameter was low (640–1100 µm), representing the first stage of development. In the second stage, C. nasus exhibited two distinct types. The first type, which included individuals 5HK05 and 6HK03, exclusively inhabited brackish estuarine waters. The second type, comprising 13 individuals, resided in higher-salinity seawater environments (Sr/Ca > 7). Furthermore, individuals 5HK01, 5HK03, 5HK07, and 6HK05 displayed a phase with a high Sr/Ca ratio compared to other fish. Freshwater coefficient analysis indicated that C. nasus in the Dawanzhou water area was unlikely to continue upstream to Dongting Lake in the middle reaches of the Yangtze River but may have entered Poyang Lake through its mouth or reproduced in its upper reaches. Analysis of sexual maturity and migration history suggested that the Dawanzhou section primarily serves as a migration channel for C. nasus, with a potential spawning ground for this high-value fish located nearby. Full article

Large-scale intensive feeding triggered reduced growth performance and nutritional value. Exogenous probiotics can promote the growth performance and nutritional value of fish through improving the intestinal microbiota. However, detailed research on the correlation between the intestinal microbiota, growth performance, and nutritional value remains to be elucidated. Therefore, we performed metagenomic and metabolomic analysis to investigate the effects of probiotic addition to basal diet (1.0 × 10⁸ CFU/g) (PF) and water (1.0 × 10⁸ CFU/g) (PW) on the growth performance, muscle nutritional value, intestinal microbiota and their metabolites, and glucolipid metabolism in Coilia nasus. The results showed that FBW, BL, and SGR were enhanced in PF and PW groups. The concentrations of EAAs, TAAs, SFAs, MUFAs, and PUFAs were increased in PF and PW groups. Metagenomic and metabolic analyses revealed that bacterial community structure and metabolism were changed in the PF and PW groups. Moreover, adding probiotics to diet and water increased SCFAs and bile acids in the intestine. The gene expression associated with lipolysis and oxidation (hsl, pparα, cpt1, and acadm) and glycolysis (gck and pfk) was upregulated, while the gene expression associated with lipid synthesis (srebp1, acc, dgat, and elovl6) and gluconeogenesis (g6pca1, g6pca2, and pck) was downregulated in the liver. Correlation analysis displayed that hepatic glucolipid metabolism was regulated through the microbiota–gut–liver axis. Mantel test analysis showed that growth performance and muscle nutritional value were improved by the gut–liver axis. Our findings offered novel insights into the mechanisms that underlie the enhancement of growth performance and nutritional value in C. nasus and other fish by adding probiotics. Full article

Coilia nasus are an important fish resource in the Yangtze River, and the Yangtze River Estuary is a crucial migration pathway for them. In this study, we used otolith microchemistry to analyze the strontium/calcium (Sr/Ca) ratios and Sr contents in the sagitta otolith of C. nasus from the south branch (SB) and north branch (NB) of the Yangtze River Estuary and obtained the diversity of migration patterns and spawning ground distribution for C. nasus. The results indicate that C. nasus from both branches include two types of habitat history: freshwater (F)–brackish water (B) (Type I) and F-B seawater (S) (Type II), with Type I being dominant at 62.50% in both branches. The C. nasus from the SB comprise six migration patterns, while that from the NB has seven migration patterns. The C. nasus from both branches hatch in F habitats. At the time of capture, the C. nasus from the SB predominantly remain in F, accounting for 62.5%, while C. nasus from the NB primarily stay in B, accounting for 87.5%. Throughout the migration process, C. nasus from both branches switch between different habitats, with C. nasus from the NB exhibiting more frequent transitions between F and B, showing a greater reliance on the estuarine brackish habitat. The radius of the first blue region near the core (L_f) and freshwater coefficient (Fc) of the otolith for C. nasus from both branches are divided into three groups: long-distance freshwater dependence (LD), medium-distance freshwater dependence (MD), and short-distance freshwater dependence (SD), with the LD only appearing in the SB, while the NB is primarily represented by MD. There is a correlation between the differences in L_f among different groups of C. nasus and the differences in the distance from the spawning grounds of C. nasus in different sections of the Yangtze River to the estuary (D_YRE), reflecting the distribution pattern of C. nasus spawning grounds in different sections of the Yangtze River. This study provides theoretical guidance for the protection of migration pathways and maintenance of spawning grounds for C. nasus, which have significant practical value in the precise management of C. nasus resources in the Yangtze River Estuary. Full article

To reveal the effects of waterborne copper stress on gene expression changes, molecular pathways, and physiological functions in Coilia nasus, juvenile fish were equally divided into two experimental groups, and the copper levels were 1.61 ± 0.03 mg/L (copper-exposed group) and 0 mg/L (control group), respectively. After 4 h, gill tissue samples were collected for transcript sequencing analysis, and two libraries were constructed from the copper treatment group (Cu) and the control group (C) and sequenced using Illumina sequencing technology. The results showed that approximately 40.2–46.0 M clean reads were obtained from each library, and the percentage of uniquely mapped transcripts ranged from 80.57 to 84.93%. A total of 3915 differentially expressed genes (DEGs) were identified under waterborne copper stress, among which 1300 genes were up-regulated, and 2615 genes were down-regulated. Twelve DEGs were randomly selected for quantitative RT-PCR (qRT-PCR) analysis, and the results confirmed that the transcriptome analysis was reliable. Furthermore, the DEGs were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and the results showed that most of the DEGs were involved in metabolic pathways, including steroid biosynthesis, glutathione metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling pathways. Furthermore, due to the waterborne copper levels, gsk-3β was significantly up-regulated, while other metabolism-related genes (tor, pi3k, lpl, aqp7, fabp3) were significantly down-regulated. In addition, the copper-exposed group significantly reduced the expression of some immunity genes (ifn-γ, stat1, cxcl10, and tgf-β), and enhanced the expression of il-1β and tnf-α. In summary, these results indicated that copper causes metabolic disorders and insufficient energy supply in the body, and induces oxidative stress, which results in reduced immune functions. Full article

Recently, probiotics have been widely applied for the in situ remediation of aquatic water. Numerous studies have proved that probiotics can regulate water quality by improving the microbial community. Nitrogen cycling, induced by microorganisms, is a crucial process for maintaining the balance of the aquatic ecosystem. Nevertheless, the underlying mechanisms by which probiotics enhance water quality in aquatic systems remain poorly understood. To explore the water quality indicators and their correlation with nitrogen cycling-related functional genes, metagenomic analysis of element cycling was performed to identify nitrogen cycling-related functional genes in Coilia nasus aquatic water between the control group (C) and the groups supplemented with probiotics in feed (PF) or water (PW). The results showed that adding probiotics to the aquatic water could reduce the concentrations of ammonia nitrogen (NH₄⁺-N), nitrite (NO₂⁻-N), and total nitrogen (TN) in the water. Community structure analysis revealed that the relative abundance of Verrucomicrobiota was increased from 30 d to 120 d (2.61% to 6.35%) in the PW group, while the relative abundance of Cyanobacteria was decreased from 30 d to 120 d (5.66% to 1.77%). We constructed a nitrogen cycling pathway diagram for C. nasus aquaculture ponds. The nitrogen cycle functional analysis showed that adding probiotics to the water could increase the relative abundance of the amoC_B and hao (Nitrification pathways) and the nirS and nosZ (Denitrification pathways). Correlation analysis revealed that NH₄⁺-N was significantly negatively correlated with Limnohabitans, Sediminibacterium, and Algoriphagus, while NO₂⁻-N was significantly negatively correlated with Roseomonas and Rubrivivax. Our study demonstrated that adding probiotics to the water can promote nitrogen element conversion and migration, facilitate nitrogen cycling, benefit ecological environment protection, and remove nitrogen-containing compounds in aquaculture systems by altering the relative abundance of nitrogen cycling-related functional genes and microorganisms. Full article

The longjaw tapertail anchovy Coilia nasus, which migrates from ocean to freshwater for spawning in spring, is an important anadromous fish with ecological and cultural significance. To determine parasite infection in anadromous C. nasus, a total of 103 fish from the Yangtze River were collected and examined in 2021 and 2022. The overall infection prevalence of nematodes in C. nasus was 100%, with a mean intensity of 13.81 ± 16.45. The mean intensity of nematode infections in 2022 was significantly higher than that observed in 2021 across all sampling sites (p < 0.05). Nematodes were widely detected in the mesentery, pyloric cecum, stomach, and liver, among which the mesentery accounted for the highest proportion, reaching up to 53.52%. A total of eight ascaridoid nematodes belonging to the family Anisakidae and Raphidascarididae were identified by using morphological characters and molecular biological techniques, including two species of Anisakis, five species of Hysterothylacium, and one species of Raphidascaris. A. pegreffii was found as the predominant species, accounting for 48.65% of all identified parasitic nematodes in liver, while Raphidascaris sp. was the most common nematode in the mesentery, pyloric cecum, and stomach, reaching up to 39.81%, 36.21%, and 74.36%, respectively. The present study systematically investigated the parasitic status and community structure of the nematode in C. nasus during its migration in the Yangtze River. This research provides a foundation for studying the impact of nematode parasitism on the reproductive migration and population recruitment of C. nasus, and offers valuable insights for biomarker screening and nematode identification in C. nasus. Full article

Coilia nasus is a typical anadromous migratory fish found in the lower reaches of the Yangtze River. Every year, C. nasus clusters offshore and swims upstream along the Yangtze River into the tributaries and lakes in the middle and lower reaches of the Yangtze River to breed. In this study, female C. nasus were collected as study subjects from the Chongming section of Shanghai, the Taizhou section of Jiangsu, and the Anqing section of Anhui. Their ovaries were used to examine tissue sections and investigate gene expression, including the follicle-stimulating hormone receptor (fshr), the luteinizing hormone receptor (lhr), kisspeptin-1 (kiss1), and forkhead box l2 (foxl2), which are related to reproductive development, while the serum levels of estrogen (including estradiol, E2) and progestins (including 17α,20β-dihydroxy-4-pregenen-3-one, 17α,20β-DHP) were also analyzed. Our results showed that, first, the growth period of the oocytes was small in stage II of ovarian development, in which both E2 and 17α,20β-DHP levels and gene expression were low. Then, in stage III, the growth period of the oocytes became large, and the yolk granules and oil droplets began to appear. Simultaneously, E2 and the expression of kiss1 and foxl2 were significantly elevated. Finally, stage IV was the period of a large amount of accumulation of nutrients in the oocytes, and 17α,20β-DHP levels and the expression of fshr and lhr were significantly elevated. These results enrich the theoretical study of ovarian development in the natural population of C. nasus, supplementing the biological basis of C. nasus reproduction and scientifically supporting the study of C. nasus population ecology and resource conservation. Full article

The survey of fish diversity is an important part of the protection of the ecological health of rivers and lakes. Environmental DNA technology is a new tool to improve the accuracy of traditional morphological surveys of biodiversity and to monitor the amount of diversity. At present, there are few studies on monitoring fish diversity in lake inlets using eDNA technology. In this study, we used various types of estuaries in the Dianchi basin as the research object, used environmental DNA technology to monitor the fish diversity in typical estuaries, and analyzed the temporal and spatial changes and the relationship between environmental factors and fish diversity. In the Dianchi basin, we identified a total of 63 fish species belonging to 8 different orders, 21 families, and 51 genera across two seasons. The Carpidae family had the highest number of species, with Carassius auratus being the most prevalent species. The Shannon index analysis yielded a p-value of 0.0018 (<0.05), suggesting significant seasonal variations in the fish community structure within the typical estuaries of the Dianchi basin. Furthermore, the β-diversity accounted for 59.6% and 57% of the variations in fish communities among the various estuary types in March and July, respectively. Fish species varied considerably between estuaries, with Carassius auratus, Cyprinus carpio, Rhodeus sinensis, Acheilognathus chankaensis, and Coilia nasus all occurring at various points. The agricultural estuary differed substantially from the urban, suburban, and lake areas. Redundancy analysis revealed that the fish community structure during the dry period was primarily influenced by total phosphorus, pH, total nitrogen (TN), and chlorophyll. Conversely, during the rich period, the fish community structure was mainly influenced by dissolved oxygen and TN. This study demonstrated the utilization of environmental DNA technology in assessing the ecological health of rivers and lakes, specifically highlighting its effectiveness in exposing the ecological condition of a representative Dianchi estuary. Full article

In order to study the community of fishery resources, five sampling sections were set up in the lower Yellow River from 2019 to 2022 to investigate the diversity of fishery resources. A total of 54 fish species were identified in the survey, belonging to 9 orders, 19 families, and 48 genera. The number of species reached its highest level since the Integrated Water Regulation of the Lower Yellow River in 1999. The original rare and endangered fish species in the lower reaches of the Yellow River, such as Coilia nasus, Rhinogobio nasutus, and Pseudobagrus ussuriensis, have reappeared in the lower reaches. The population and abundance of main economic fish and common small-sized fish in the lower reaches of the Yellow River have increased. These signs all indicate that, and the fishery resources are recovering slowly in the lower Yellow River. By comparing the fish resources of various investigation sections, it was found that there are differences in fish diversity: the closer to the estuarine waters, the higher the variety of fish in the Yellow River at the upper level of the taxonomic category. However, that section of the lower Yellow River where species evenness, species diversity, and community structure of fishery resources were most stable was the confluence of Dongping Lake into the Yellow River, which has the most significant number of fish species, the smallest Λ⁺ value, and the most extensive G-F index. The above results indicate that Dongping Lake, as the only lake connected to the lower reaches of the Yellow River, plays an essential role in replenishing fish resources in the lower reaches of the Yellow River. Full article

The process by which spermatogonial stem cells (SSCs) continuously go through mitosis, meiosis, and differentiation to produce gametes that transmit genetic information is known as spermatogenesis. Recapitulation of spermatogenesis in vitro is hindered by the challenge of collecting spermatogonial stem cells under long-term in vitro culture conditions. Coilia nasus is a commercially valuable anadromous migrant fish found in the Yangtze River in China. In the past few decades, exploitation and a deteriorating ecological environment have nearly caused the extinction of C. nasus’s natural resources. In the present study, we established a stable spermatogonial stem cell line (CnSSC) from the gonadal tissue of the endangered species C. nasus. The cell line continued to proliferate and maintain stable cell morphology, a normal diploid karyotype, and gene expression patterns after more than one year of cell culture (>80 passages). Additionally, CnSSC cells could successfully differentiate into sperm cells through a coculture system. Therefore, the establishment of endangered species spermatogonial stem cell lines is a model for studying spermatogenesis in vitro and a feasible way to preserve germplasm resources. Full article

Coilia nasus is a threatened migratory species in the Yangtze River Basin. To reveal the genetic diversity of natural and farmed populations of C. nasus and the status of germplasm resources in the Yangtze River, the genetic diversity and structure of two wild populations (Yezhi Lake: YZ; Poyang Lake: PY) and two farmed populations (Zhenjiang: ZJ; Wuhan: WH) of C. nasus were analyzed using 44,718 SNPs obtained via 2b-RAD sequencing. The results indicate that both the wild and farmed populations had low genetic diversity, and germplasm resources have undergone varying degrees of degradation. Population genetic structure analyses indicated that the four populations may have come from two ancestral groups. Different amounts of gene flow were identified among WH, ZJ, and PY populations, but gene flow among YZ and other populations was low. It is speculated that the river–lake isolation of Yezhi Lake is the main cause of this phenomenon. In conclusion, this study revealed that genetic diversity reduction and germplasm resource degradation had occurred in both wild and farmed C. nasus, suggesting that conservation of its resources is of great urgency. This study provides a theoretical basis for the conservation and rational exploitation of germplasm resources for C. nasus. Full article