Carp Aquaculture Research Articles

Establishment and Characteristics of the Spermatogonial Stem Cell Line from the Yellow River Carp (Cyprinus carpio haematopterus)

To address the growing consumer demands for improved fish meat quality, desirable morphological traits, and sustainable production practices, researchers have intensified efforts in the selective breeding and genetic improvement of carp (Cyprinus carpio) varieties. However, traditional breeding methods are often time-consuming and inefficient, which poses challenges to the sustainable development of the carp aquaculture industry. The establishment of germ stem cell lines offers a crucial tool for the study of germ cells, genetic improvement, and species conservation. In this study, we successfully established a spermatogonial stem cell line (YRSSCs) from Yellow River carp (Cyprinus carpio haematopterus) that can be cultured in vitro for the long term. We optimized the culture conditions to maintain their self-renewal and differentiation capabilities. The results demonstrated that YRSSCs have a diploid karyotype and can stably proliferate for over a year in L-15 medium supplemented with 5 mmol/L HEPES, 50 μmol/L β-mercaptoethanol, 15% FBS, 2 ng/mL bFGF, 2 ng/mL LIF, 1% carp serum, 800 IU/mL penicillin, 0.8 mg/mL streptomycin, 2 μg/mL amphotericin B, 1% zebrafish embryo extract, and 1% glutamine at 30 °C in the absence of CO2. The cells exhibited a typical germ stem cell gene expression profile, with strong expression of the vasa, plzf-a, and Oct4-a genes. Additionally, this study found that YRSSCs possess the ability to differentiate in vitro and functionally colonize in vivo within recipient bodies. This research explored the establishment of YRSSCs and their differentiation potential both in vitro and in vivo, providing a novel strategy for the genetic improvement of aquaculture fish species through germ stem cell-based gene editing and transplantation technologies.

Establishment of the Tgf2-based anti-hemorrhagic disease system THVS and analysis of its disease resistance effects in Gobiocypris rarus.

Establishment of the Tgf2-based anti-hemorrhagic disease system THVS and analysis of its disease resistance effects in Gobiocypris rarus.

The Antiviral Efficacy of Andrographolide Against Grass Carp Reovirus In Vitro and In Vivo.

The Antiviral Efficacy of Andrographolide Against Grass Carp Reovirus In Vitro and In Vivo.

Host-Microbiota-Parasite Interactions in Grass Carp: Insights from Ichthyophthirius multifiliis Infection.

The ciliate parasite Ichthyophthirius multifiliis poses significant threats to grass carp (Ctenopharyngodon idellus) aquaculture. However, the limited understanding of host microbiota shifts and immune responses hinders effective control strategies. This study integrated analyses of host pathological indices, immune response and skin/gill/gut microbiota shifts after I. multifiliis infection. A histopathological examination identified gill and fin tissues embedded with I. multifiliis, accompanied by epithelial necrosis, and inflammatory cell infiltration. Biochemical profiling revealed marked elevations in aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea (UREA), and creatinine (CREA) levels, indicating impaired hepatic and renal function. Quantitative RT-PCR analyses demonstrated the up-regulation of mucosal immune gene IgT and pro-inflammatory cytokine TNF-α while increasing the trend of systemic immune gene IgM. 16S rRNA sequencing revealed significant reductions in skin microbiota diversity. At the genus level, opportunistic pathogens Aeromonas and Vibrio proliferated in the intestine, whereas Flavobacterium and Candidatus Megaira increased in the skin and gills. Correlation analyses identified positive associations between Aeromonas/Vibrio abundance and host phenotype, contrasting with negative correlations observed for Sphingomonas, Acinetobacter, and Leifsonia. These findings demonstrate that I. multifiliis infection induces host microbiome dysbiosis and potentially opportunistic bacterial infections. This investigation advances our understanding of tripartite host-microbiota-parasite interactions and supports microbial community-based parasitosis control in fish culture.

Chinese yam polysaccharide induces the differentiation and natural antibody secretion of IgM+ B cells to prevent Aeromonas hydrophila infection in grass carp.

Chinese yam polysaccharide induces the differentiation and natural antibody secretion of IgM+ B cells to prevent Aeromonas hydrophila infection in grass carp.

Evaluation of a novel halophile Probiotic, Virgibacillus salarius, for common carp aquaculture: effects on growth performance, nonspecific immune responses, antioxidant defence and immune gene expression

Evaluation of a novel halophile Probiotic, Virgibacillus salarius, for common carp aquaculture: effects on growth performance, nonspecific immune responses, antioxidant defence and immune gene expression

Genetic Characterization of the Thymidine Kinase of Koi Herpesvirus 3 in Sulaymaniyah Province, Iraq

Koi herpesvirus 3 (KHV-3) is nominated as an emerging, highly devastating, and contagious viral disease with severe economic losses in the carp aquaculture industries worldwide. Carp rearing under intensive culture conditions is constantly vulnerable to infection by various pathogens in the water. Water temperature has a major influence on the onset and severity of the disease. Since common carp have gained importance in the Iraqi fish industry, the investigation and control of associated diseases, including KHV, are warranted. We confirmed the first detection of the KHV from the collected specimens from the suspected cages in the Sulaymaniyah region. Also, an analysis of the thymidine kinase (TK) gene sequence of the KHV showed that the virus strain had a point mutation (proline, P193) instead of threonine, T193. The isolated KHV strains were subdivided into three clades with three distinct genotypes: Asian (Iranian, Indonesian, Japanese, and Chinese), European (UK), and North American (USA and Mexico) genotypes. The virus sequences were more closely related to the Iranian and Indonesian genotypes. This report describes the first isolation and genetic characterization of koi herpesvirus (KHV) in the Sulaymaniyah province, which is important for efficacious management and vaccination programs in the future to control KHV infection in carp cages in Northern Iraq.

Analysis of GCRV Pathogenesis and Therapeutic Measures Through Proteomic and Metabolomic Investigations in GCRV-Infected Tissues of Grass Carp (Ctenopharyngodon idella).

Hemorrhagic disease caused by grass carp reovirus (GCRV) infection is a major problem affecting the grass carp aquaculture industry. Therefore, inhibiting the spread of GCRV infection is of great economic significance. Herein, we sequenced five tissues (gill, liver, intestine, kidney, and muscle) from grass carp before and after GCRV infection using data-independent acquisition proteomic and untargeted metabolomic technologies, and quantitatively identified 10,808 proteins and 4040 metabolites. Then, we analyzed the differentially expressed proteins (DEPs) and metabolites (DEMs) before and after GCRV infection in the five tissues. Gene ontology analysis revealed that the five tissue DEPs were enriched in metabolic, including carbohydrate and lipid metabolic processes. Chemical taxonomy analysis showed that the categories of DEMs mainly included carbohydrates and lipids, such as fatty acids, glycerophospholipids, steroids, and their derivatives. Both the proteomic and the metabolomic data showed that GCRV affected the carbohydrate and lipid metabolism in the host. Shared pathway analysis was performed at both the protein and metabolic levels, showing significant enrichment of the glycolysis and pentose phosphate pathways (p < 0.001). Further analysis of glycolysis and pentose phosphate pathway inhibitors revealed that these two pathways are important for GCRV replication. As the kidney was the most affected among the five tissues, we analyzed the butanoate metabolism in the kidney, which revealed that most of the differentially expressed proteins and differently expressed metabolites in the butanoate metabolism were related to the TCA cycle. Further investigation showed that fumaric acid, an intermediate product in the TCA cycle, significantly inhibited GCRV replication in the CIK cells (p < 0.001), and that this inhibitory effect may be related to its induction of interferon system activation. The addition of fumaric acid to feed increased the survival rate of juvenile grass carp by 19.60% during GCRV infection, and protected the tissues of those infected with GCRV, making it a potential anti-GCRV feed additive. Our results provide new perspectives on GCRV pathogenesis and antiviral strategies for grass carp.

Population Genetic Investigation of Hypophthalmichthys nobilis in the Yangtze River Basin Based on RAD Sequencing Data.

The Bighead carp (Hypophthalmichthys nobilis), a primary freshwater aquaculture species in China, faces challenges due to over-exploitation and environmental changes. We leveraged RAD-seq to perform a comprehensive population genetic analysis on 14 H. nobilis populations sampled from the Yangtze River (13 populations) and the Marseilles Reach of the Illinois River (one population). Analysis of genetic diversity showed that different parameters demonstrated varied inferences, and notably, Zhongxian (ZX2), Wanhzou (WZ2), Yangzhou hatchery (YZYZ), Yangzhou (YZ), and Taihu (TH) populations showed apparent heterozygote deficiency. Linkage disequilibrium (LD) analysis exhibited a trend of higher linkage disequilibrium in populations from the upper reaches of the Yangtze River, followed by those from the middle reaches and then those from the lower reaches. Additionally, the reconstructed polygenetic tree and PCA plot clustered all populations into 2 major subgroups, while the results of structure analysis indicated 4 ancestors. The pairwise FST values ranged from 0 to 0.5530. Among these, high FST values (0.1931-0.5530) were only observed between populations WZ2, YZ, YZYZ, and the remaining 11 populations. Furthermore, genetic bottlenecks were observed in all populations 20-30 thousand years ago. Overall, the research offers insights essential for genetic management practices for sustainable aquaculture and biodiversity conservation of bighead carp.

Identification, Expression, Characteristic Analysis, and Immune Function of Two Akirin Genes in Grass Carp (Ctenopharyngodon idella).

Intensive aquaculture of grass carp often leads to decreased immunity and increased disease prevalence, resulting in economic losses. Improving grass carp immunity is therefore a critical strategy for addressing these challenges. Akirin reportedly participates in myogenesis, growth, and immune responses. However, its role in grass carp remains unclear. Herein, we isolated akirins from the spleen of grass carp and analyzed their tissue-specific expression. Akirin expression was detected following treatment with poly (I:C), LPS, and Aeromonas hydrophila (A. hydrophila). The immunological function of the akirin protein was evaluated in head kidney leukocytes (HKLs). The results revealed that the coding sequence (CDS) of akirin1 is 570 bp, encoding 189 amino acids. There was one predicted nuclear localization signal (NLS) and two predicted α- helix domains. The CDS of akirin2 is 558 bp, encoding 185 amino acids. There were two predicted NLSs and two predicted α-helix domains. Tissue-specific expression analysis showed that akirins are widely detected in grass carp tissues. akirin1 was highly detected in the brain, kidneys, heart, spleen, and gonads, while akirin2 was highly detected in the brain, liver, gonads, kidneys, spleen, and heart. The mRNA levels of akirins were promoted after treatment with poly (I:C), LPS, and A. hydrophila. Recombinant akirin proteins were produced in Escherichia coli (E. coli). il-1β, ifnγ, il-6, tnfα, il-4, iκbα, and nfκb were markedly increased in grass carp HKLs by treatment with the akirin protein. These results suggest that akirins play a role in the immunological regulation of grass carp.

Silybin attenuates avermectin-induced oxidative damage in carp respiration by modulating the cGAS-STING pathway and endoplasmic reticulum stress.

Avermectin is a commonly used insect repellent for aquaculture and crops, but it is easy to remain in the aquatic environment, causing organism disorders, inflammation, and even death. This resulted in significant economic losses to the carp aquaculture industry. Silybin has antioxidant, anti-inflammatory, and anti-apoptotic properties. However, it is unclear whether Silybin counteracts gill damage caused by avermectin exposure. Therefore, we modeled avermectin exposure and Silybin intervention by adding 2.404 μg/L avermectin to water and 400 mg/kg of Silybin to feed. Gill tissue was collected and analyzed in depth during a 30-day experimental period. The results showed that avermectin exposure induced structural disorganization of gill filaments and led to increased reactive oxygen species, inhibition of antioxidant functions, induction of inflammatory responses, and endoplasmic reticulum stress in addition to the endogenous apoptotic pathway. In contrast, Silybin effectively alleviated pathological changes and reduced reactive oxygen species levels, thereby attenuating oxidative stress and endogenous apoptosis and inhibiting endoplasmic reticulum stress pathways. In addition, Silybin reduced avermectin-induced gill tissue inflammation in carp, and it is considered that it might modulate the cGAS-STING pathway. In summary, Silybin alleviates avermectin-induced oxidative damage within the carp's respiratory system by modulating the cGAS-STING pathway and endoplasmic reticulum stress. The main goal is to understand how Silybin reduces oxidative damage caused by avermectin in carp gills, offering management strategies. Concurrently, the current study proposes that Silybin can serve as a dietary supplement to reduce the risks brought on by repellent buildup in freshwater aquaculture.

Dietary administration of green macroalgae (Ulva intestinalis) on growth performance, serum immune parameters, and gene expression in Common carp (Cyprinus carpio)

Abstract The purpose of this experiment was to assess the effects of the green macroalgae (Ulva intestinalis) on growth performance, immune parameters of serum and mucus, liver enzymes and the expression of genes related to growth (GH and IGF-1), and immunity (IL1-β and Lyz) in common carp (Cyprinus carpio). The test was carried out in eight weeks with the treatments supplemented with 0 (control), 0.25%, 0.5%, and 1% macroalgae and three replications for each group. At the end of the course, growth indices, serum and mucus total protein, total immunoglobulin, lysozyme, and liver enzymes including alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase were evaluated. Additionally, the expression of growth (GH and IGF-1) and Immunity (IL1-β and Lyz) genes was evaluated using real-time PCR in the brain, liver, and intestine. Based on the results, a significant difference was observed in the levels of total protein, total immunoglobulin, and mucus lysozyme in the fish that received 1% U. intestinalis compared to the control group (P&lt;0.05). In addition, the amount of total protein, total immunoglobulin, and lysozyme in the control group and the other treatments represented a significant difference (P&lt;0.05). Although the initial weight did not show a significant difference among the treatments (P&gt;0.05), the final growth parameters significantly varied in different treatments, with the highest final weight observed in fish fed with 0.25% algae (P&lt;0.05). The results of the expression of immune genes lysozyme (Lyz) and interleukin-1 (IL-1) indicated a significant difference with the control group (P&lt;0.05), representing an increasing pattern with the rising percentage of macroalgae (P&lt;0.05). The supplement was also found effective in promoting the expression of growth hormone (GH) and insulin-like growth factor (IGF-1) compared to the control fish (P&lt;0.05), revealing an increasing pattern for the IGF-1 gene with the elevated level of the supplement. In general, according to the results of the present study, U.intestinalis can be recommended in carp aquaculture, most preferably at the level of 1% of daily feed, as it could significantly enhance the growth and innate immunity of fish.

Results of iodine-based treatment application in carp aquaculture within closed water systems

The study aimed to monitor the prevalence of ectoparasites and bacterial infestations in carp and to determine effective dosages of a new iodine-based treatment for disease prevention. The research found that carp were affected by ectoparasites G. kobayashii at 43.32%, L. cyprinacea at 46.67%, and P. lusiana at 31.71% in fish farming facilities within the Sumy Region. Treatment with the iodine-based product resulted in a reduction of infestation levels to 0.2%, including a decrease in the incidence of gyrodactylosis by 89.92-97.35%, lernaeosis by 79.13-95.91%, and philometroidosis by 81.30-91.16% compared to monitoring results. In investigations of bacterial infestations, it was found that the contamination of carp was higher for E. coli at the PC “Shmatukha” by 8.0%, Aeromonas hydrophila by 47.97%, and Aeromonas salmonicida by 31.39%. Additionally, Pseudomonas anguilliseptica was detected at 19.48%, Streptococcus iniae at 13.27%, and Micrococcus spp. at 38.14% at LLC “Ryasnyanske”. The presence of Staphylococcus aureus was recorded at 21.37%, and Listeria monocytogenes at 11.43% at LLC “Bdzhola”; these figures were lower than those observed in other farms. Following treatment with the iodine-based agent, contamination of fish by E. coli decreased by 98.96% at the PC “Shmatukha”, 99.2% at LLC “Bdzhola”, and 84.32% at LLC “Ryasnyanske”. Contamination of carp by A. hydrophila decreased by 94.51% at the PC “Shmatukha”, 80.28% at LLC “Bdzhola”, and 99.15% at LLC “Ryasnyanske”. The presence of A. salmonicida was reduced by 97.23% at the PC “Shmatukha”, 94.00% at LLC “Bdzhola”, and 79.06% at LLC “Ryasnyanske”. Contamination by S. aureus decreased by 92.15% at the PC “Shmatukha”, 98.74% at LLC “Bdzhola”, and 93.89% at LLC “Ryasnyanske”. The levels of S. iniae decreased by 80.90% at the PC “Shmatukha”, 99.63% at LLC “Bdzhola”, and 83.30% at LLC “Ryasnyanske”. Contamination by L. monocytogenes was reduced by 96.25% at the PC “Shmatukha”, 96.08% at LLC “Bdzhola”, and 98.13% at LLC “Ryasnyanske”. Furthermore, Micrococcus spp. levels decreased by 93.74% at the PC “Shmatukha”, 96.37% at LLC “Bdzhola”, and 92.26% at LLC “Ryasnyanske”, in comparison to the monitoring results. The practical value of this study lies in controlling the spread of ectoparasites and developing preventive measures to eliminate ectoparasites and bacterial infestations in carp prior to their release into water bodies

Synergistic toxic effects of copper sulfate and trichlorfon on the health and intestinal microbiota of gibel carp Carassius auratus gibelio

Synergistic toxic effects of copper sulfate and trichlorfon on the health and intestinal microbiota of gibel carp Carassius auratus gibelio

Metabolites and metabolic pathway analysis of sulfadimidine in carp (Cyprinus carpio) based on UHPLC-Q-orbitrap HRMS

Metabolites and metabolic pathway analysis of sulfadimidine in carp (Cyprinus carpio) based on UHPLC-Q-orbitrap HRMS

Design and Application of New Aeration Device Based on Recirculating Aquaculture System

This study optimized the design of an aeration device for pond engineered recirculating aquaculture systems (RASs) whose application is aimed at increasing dissolved oxygen (DO) levels in RAS aquaculture practice. DO is a key factor in aquaculture productivity, and oxygenators are the power devices used for regulating its levels in aquaculture ponds. In this study, grass carp (Ctenopharyngodon idellus) aquaculture trials were conducted in a self-built RAS by using the new aeration device (NAD); the microporous and impeller aeration components were individually tested in terms of performance, and then combined for the orthogonal testing of their operating parameters in order to assess the NAD’s oxygenation capacity. The test results show that the device effectively increased the dissolved oxygen levels in the RAS tank, enhanced the upper–lower water layer exchange and directional flow, and met the design and parameter selection requirements. Compared with the existing RAS oxygenation equipment, the NAD operated with the optimal parameters and increased the oxygen transfer rate in the pond water tank by 122%.

Effect of dietary heat-killed Lactiplantibacillus plantarum VSG3 on growth, immunity, antioxidant status, and immune-related gene expression in pathogen-aggravated Cyprinus carpio

Effect of dietary heat-killed Lactiplantibacillus plantarum VSG3 on growth, immunity, antioxidant status, and immune-related gene expression in pathogen-aggravated Cyprinus carpio

FerrylHb induces inflammation and cell death in grass carp (Ctenopharyngodon idella) hepatocytes

FerrylHb induces inflammation and cell death in grass carp (Ctenopharyngodon idella) hepatocytes

Characterization of multi-copy C3 genes and association analysis of C3.1 polymorphism with GCRV resistance traits in Ctenopharyngodon idella

Characterization of multi-copy C3 genes and association analysis of C3.1 polymorphism with GCRV resistance traits in Ctenopharyngodon idella

Bioaccumulation of lead, arsenic, and mercury in vital organs of common carp (Cyprinus carpio L.): Assessment of pathological effects and possible hazards associated with human consumption.

Pollution of aquatic environments with heavy metals causes severe adverse effects on fish, invertebrates, and human. The importance of this study lies in the fact that long-term ingestion of heavy metal-contaminated fish can result in the accumulation of harmful metals in numerous organs and pose a major risk to human health. The current study was designed to investigate the concentrations of toxic arsenic (As), lead (Pb), and mercury (Hg) in the liver, gills, and muscles of highly consumed aqua cultured common carp (Cyprinus carpio L.) in Baqubah city, to evaluate the toxicopathological bioaccumulation of As, Pb, and Hg in consumed fish and the potential human health risk after consumption and give clear indication for a status of heavy metal contamination for water used in aquaculture of common carp (C. carpio L.). A total of 10 Fresh fish of common carp (C. carpio L.) were randomly selected from local Baqubah markets/Diyala province/Iraq in different interval from September 2022 to January 2023. The source of fish in Baqubah's local markets is fish aquacultured in earthen ponds as well as cages in the Tigris River in Diyala province. Flame atomic absorption spectrometer was used to estimate the level of As, Pb, and Hg in liver, gills, and muscles of collected fish. Histopathological sections were prepared for evaluation of toxic pathological effects of metals on C. carpio organs. Bioaccumulation of arsenic and lead in liver, gill, and muscle samples was within and less than the permissible limit set by WHO while the bioaccumulation of mercury exceeds the permissible limits set by WHO. Histopathological findings of the gill section showed telangictatisis and epithelial lifting in secondary lamellae with hemorrhage and blood congestion and central venous dilation and epithelium hyperplasia with complete fusion of the secondary lamellae and edema in the filamentary epithelium in addition to mononuclear cells infiltration. Histopathological findings of liver revealed degenerative and necrotic changes in liver tissue distinguished by pyknosis with the existence of necrosis in cells and dilation of the sinusoids with cytoplasmic vacuolation. The bioaccumulation of mercury is higher than permitted levels in common carp (C. carpio) which indicates high contamination level of main sources for fresh waters in Diyala province mainly from Diyala and Tigris rivers.