Search Results (201)

The assessment of sperm quality is essential for improving reproductive efficiency in aquaculture species such as common carp (Cyprinus carpio). While sperm motility is widely used as a key functional indicator, the predictive value of oxidative protein markers for sperm performance remains unclear. In this study, sperm motility and kinematic parameters were assessed using computer-assisted sperm analysis (CASA). Markers of oxidative status, advanced oxidation protein products (AOPPs), ceruloplasmin (CP), and total protein concentration were quantified in samples. The results showed relatively high total motility (70.51%) and progressive motility (69.00%), indicating good sperm quality. No statistically significant correlations (p > 0.0.5) were found between AOPP or CP and sperm motility. Protein concentration was positively associated with motility parameters, including curvilinear velocity (VCL) and amplitude of lateral head displacement (ALH). A significant negative correlation was found between Fulton’s condition factor (FCF) and AOPP (r = −0.686; p < 0.05), indicating that individuals with higher body condition had lower oxidative protein damage. These findings suggest that oxidative protein markers may not directly reflect sperm motility, highlighting the potential value of including additional oxidative stress-related parameters in sperm quality assessment. Full article

This study highlights the strong ability of a new bacterial strain, Hafnia paralvei UUNT_MP29, isolated from the gastrointestinal tract (GIT) of common carp (Cyprinus carpio), to break down polystyrene (PS). As an omnivorous bottom feeder, C. carpio is constantly exposed to microplastics, creating a unique environment that favors the evolution of specialized microbiota capable of degrading polymers. Genomic analysis of the isolate identified key homologs involved in xenobiotic breakdown, including alcohol dehydrogenase (Adh), 3-hydroxybutyrate dehydrogenase (HDH), and a small glutamine-rich tetratricopeptide repeat-containing protein (SGTA), showing a strong metabolic system for processing long-chain hydrocarbons. Growth experiments showed the strain quickly adapted, reaching maximum cell density and forming mature biofilms by Day 16. Gravimetric analysis confirmed that H. paralvei UUNT_MP29 uses PS as its primary carbon source, with a significant weight loss of 16.76% over 16 days. Kinetic modeling indicated the degradation follows first-order kinetics (R² = 0.9243) with a high degradation rate constant (k) of 0.2078 day⁻¹. Surface analyses using FTIR and SEM confirmed extensive oxidative changes, as evidenced by the rising Carbonyl Index and surface erosion. TGA also showed reduced thermal stability of the treated polymer, suggesting microbial chain scission. These findings demonstrate the strong degradative ability of H. paralvei UUNT_MP29 and highlight the GIT of plastic-exposed aquatic animals as a promising area for discovering powerful biocatalysts for microplastic cleanup. Full article

Glyphosate and its primary metabolite aminomethylphosphonic acid (AMPA) are widely detected in aquatic environments, yet their combined effects on fish remain insufficiently understood. This study used label-free blood plasma proteomic profiling to explore molecular patterns associated with 14-day exposure of juvenile common carp (Cyprinus carpio) to environmentally relevant concentrations of glyphosate (100 µg/L), AMPA (100 µg/L), and their mixture (50 + 50 µg/L). Across the three exposure groups, 41 proteins of interest showed pronounced abundance differences relative to the control based on fold-change selection criteria. These proteins were mainly associated with immune recognition, innate immune and complement-associated functions, coagulation and extracellular protease regulation, lipid/sterol transport, and extracellular matrix organization. In the mixture group, proteins of interest spanned several functional categories, suggesting that combined exposure deserves further attention in future studies of plasma-level responses to glyphosate and AMPA. Overall, these findings provide preliminary insights into blood plasma protein patterns associated with systemic responses of fish to glyphosate, AMPA, and their mixture at environmentally relevant concentrations and highlight the importance of considering parent compounds, metabolites, and their co-occurrence when assessing the potential biological effects of herbicide contamination in aquatic ecosystems. Full article

The accumulation of polyethylene (PE) in aquatic ecosystems represents a significant environmental challenge due to the polymer’s high molecular weight and chemical stability. This study investigates the biodegradation potential of Hafnia paralvei UUNT_MP29, a bacterial strain isolated from the gut of common carp (Cyprinus carpio), for low-density polyethylene (LDPE). Initial screening on LDPE-emulsified agar confirmed extracellular enzymatic activity through the formation of distinct clear zones. Quantitative analysis showed a cumulative mass loss of 24.10% by Day 16, with the most intensive degradation occurring between Days 4 and 8, which closely correlated with maximum bacterial count (CFU/mL). Kinetic modeling indicated that the degradation followed a first-order rate law (R² = 0.9269), with a rate constant (k) of 0.2991 days⁻¹ and a remarkably short half-life (t_1/2) of 2.32 days. Structural characterization via FTIR spectroscopy demonstrated oxidative transformation, evidenced by a reduction in sp³ C-H stretching and the emergence of C-O/C-O-C functional groups. SEM micrographs further confirmed extensive bio-deterioration, including surface pitting and macroscale erosion. Thermal analysis (TGA/DTG) supported these findings, showing a significant 10.95 °C decrease in the maximum degradation temperature (T_max), indicating a reduction in polymer chain length. These results suggest that H. paralvei UUNT_MP29 is a highly efficient agent for the rapid breakdown of polyethylene and highlight the potential of aquatic gut microbiota as reservoirs for plastic-degrading biotechnologies. Full article

Proximate composition, lipid classes, and fatty acid profile were comparatively analyzed in different body parts of carp (Cyprinus carpio) cultivated in Madagascar. Higher (p < 0.05) protein values (163.3–200.1 g·kg⁻¹ range) were detected in muscle tissue (epaxial, hypaxial, and tail) than in the liver tissue (118.4 g·kg⁻¹). The average lipid content showed the following decreasing tissue sequence: liver > hypaxial > tail > epaxial. The highest levels (p < 0.05) of phospholipids and sterols were obtained in the epaxial muscle part (94.0 and 24.0 g·kg⁻¹ of lipids, respectively). A high presence of free fatty acids (183.2 g·kg⁻¹ of lipids) was detected in the liver. In all tissues, α-tocopherol provided higher values (p < 0.05) than γ- and δ-tocopherol compounds; among body parts, the liver showed the highest levels (p < 0.05) for all tocopherols. Fatty acid (FA) groups revealed a higher range value (g·100 g⁻¹ of total FAs) for monounsaturated FAs (48.19–52.57) than for saturated FAs (SFAs; 28.50–29.41) and polyunsaturated FAs (PUFAs; 17.96–22.57). The following increasing sequence was observed for ω3-PUFA/ω6-PUFA ratios in body parts: liver < hypaxial < tail < epaxial. All parts of muscle tissue contained higher (p < 0.05) PUFA/SFA values (0.72–0.77) than liver (0.61). Comparison of body parts revealed an inhomogeneous distribution of bioactive compounds. The liver tissue was found a good source of valuable constituents. Full article

This study employed a 2 × 2 factorial design to investigate the transcriptomic responses of common carp intestine under the single and combined stress of high temperature and zinc. Results from Illumina RNA-seq, WGCNA, and qPCR showed high-quality sequencing data with good reproducibility. High temperature was the core driver of global transcriptomic reprogramming, inducing numerous DEGs via activating metabolic and stress signaling pathways. Zinc alleviated heat stress by reducing DEGs by 43.2% and activating DNA repair and cell cycle pathways. WGCNA identified core modules for heat response and zinc mitigation, revealing “emergency defense” and “repair adaptation” strategies. This study enriches the teleost stress adaptation theory and provides a scientific basis for healthy carp aquaculture. Full article

We evaluated the effect of our light-emitting diode (LED) light treatments (blue, peak at 468 nm; green, peak at 537 nm; red, peak at 630 nm; and white light) on the growth performance and serum lysozyme activity of the common carp Cyprinus carpio and bacterial communities in a closed recirculating system under an average power intensity of 1.29 ± 0.18 mW/cm² of LED light on the water surface of a circulating rearing system for 70 days. The specific growth rate, weight gain and K-factor were improved when carp were cultured under green or blue light. The specific lysozyme activity in the plasma of the common carp was significantly promoted under blue light compared to the green, white and red light conditions after 70 days. Compared to the other types of LED lights, the blue light treatment resulted in the lowest number of heterotrophic bacteria in the rearing water and the highest heterotrophic bacteria in the carp’s gut contents (both p < 0.05). The phyla Fusobacteria, Bacteroidetes, Tenericutes, Proteobacteria and Firmicutes were abundant in the carp’s gut contents after culturing with any of the four types of LED light. In short, the blue LED light can be considered a potential tool in sustainable aquaculture. Full article

Cyprinid herpesvirus 3 (CyHV-3) is a pathogen that causes high mortality in common carp (Cyprinus carpio) and koi. Common carp breeding lines with different genetic backgrounds exhibit different resistance levels to viral pathogens. This study aimed to determine the differences in CyHV-3 disease resistance performance between the hybrid offspring (Y × M and M × Y) of the mirror carp ‘Longke 11’ (resistant to CyHV-3) and Yellow River carp, as well as the self-crossed offspring (M and Y). The M, Y × M, M × Y and Y groups were infected with CyHV-3 by immersion. The order of mortality and the duration of death for the four groups of carp were as follows: Y group > Y × M group > M × Y group > M group. Throughout the entire infection stage, the mRNA expression levels of the viral factors thymidine kinase (TK) and open reading frame 72 (ORF72) in the four groups of carp tended to first increase but then decrease. The viral factor expression evaluated on days 30 and 31 post-infection (p.i.), which was the peak of infection mortality, was the highest in the Y group and the lowest in the M group, and compared with the Y × M group, the M × Y group had considerably lower viral gene expression (p < 0.05). The immune-related enzyme activity and content levels of the four carp groups matched the patterns of viral gene expression. On day 29 p.i., a time point with high mortality, the levels of alkaline phosphatase (AKP), glutathione peroxidase (GSH-Px) and total antioxidant capacity (T-AOC) were significantly the lowest in the Y group and significantly the highest in the M group, while the Y × M group showed a significant decrease compared to the M × Y group (p < 0.05). Quantitative real-time (q-PCR) analysis revealed that interleukin-21 receptor (IL21R), interferon regulatory factor 9 (IRF9), interferon type I (IFN-I), interleukin-6 (IL-6) and microtubule-associated protein light chain 3 (LC3), exhibited an initial increase followed by a decrease among the four experimental groups of common carp. In the peak mortality period of carp in the four groups (30 days post-infection), the expression levels of IL21R, IRF9, LC3, and IFN-I were significantly the highest in the M group and significantly the lowest in the Y group, with the mRNA expression of these genes in the M × Y group being significantly higher than that in the Y × M group (p < 0.05). In contrast, IL-6 expression levels exhibited the opposite trend. In this study, the M group exhibited the greatest resistance to CyHV-3, followed by the M × Y group, whose resistance was greater than that of the Y × M group, with the Y group showing the lowest disease resistance. Our findings demonstrate that hybridization modulates resistance to CyHV-3. Furthermore, we identified conserved immune signatures common to both susceptible and resistant carp, including the activation of nonspecific immunity and the upregulation of immune-associated genes. Full article

The common carp (Cyprinus carpio) kidney uniquely integrates excretory nephrons, renal hematopoietic tissue, and hormonally active thyroid follicles, positioning it as a candidate “multipurpose biomarker organ” for pollutants like perfluorooctanoic acid (PFOA), a prototype long-chain PFAS and persistent organic pollutant exhibiting nephrotoxic, immunotoxic, and thyroid-disrupting effects. Building on prior histological, ultrastructural, and morphometric analyses from carp exposed to waterborne PFOA (0, 200 ng L⁻¹, 2 mg L⁻¹ for 56 days), a hierarchical multipurpose index comprising nephrotoxic, immunotoxic, and thyrotoxic subindices was developed from z-scored light-, electron-microscopy, and morphometric features, enabling cross-scale integration; proximal tubule vesiculations and effete rodlet cells (RCs) were newly quantified from archival electron micrographs. The subindices captured PFOA-induced glomerular hyperfiltration with proximal protein reabsorption and collecting duct RCs recruitment (nephrotoxic); hematopoietic tissue RCs recruitment, clustering, and exocytosis (immunotoxic); and increased thyroid follicle abundance/vesiculation, cross-sectional area, and perimeter (thyrotoxic). Quantification of previously only qualitatively assessed features provided statistical validation, while radar plot integration rendered results more intuitively evident—particularly highlighting the non-monotonic thyroid response—condensing organ-level complexity into a coherent framework supporting carp kidney as a translational One Health model for multi-endpoint waterborne pollutant assessment. Full article

Benzo(a)pyrene (B[a]P) is a pervasive freshwater pollutant, yet its toxicity to the fish gallbladder remains poorly understood. This study investigated the toxicological impacts of 2.5 and 25 μg/L B[a]P on common carp (Cyprinus carpio) using histological, transcriptomic, and single-cell RNA sequencing (scRNA-seq) analyses. Results showed that the gallbladder is a primary site for B[a]P accumulation. High B[a]P concentrations caused vacuolar degeneration of mucosal epithelial cells and nuclear deformities. Transcriptomic analysis revealed that B[a]P stress triggered autoimmune homeostasis imbalance and overinhibited apoptosis. scRNA-seq identified cellular heterogeneity changes, specifically T-cell impairment and epithelial cell (EC) proliferation. Mechanistically, T-cell reduction was linked to the T-cell 2 subset, while EC proliferation involved EC 0 and EC 4 subsets, all participating in the apoptosis pathway. These findings demonstrate that the apoptosis pathway is a key target of B[a]P toxicity in the gallbladder. This work provides a cellular-level framework for assessing environmental polycyclic aromatic hydrocarbon (PAH) risks in aquaculture. Full article

Frass is the by-product of the larval meal industry and consists of leftover feed materials, exoskeleton shedding, and larval excrement of black soldier fly larvae (BSFL). To assess the impact of dietary frass (BSFLF) on the growth, feed consumption, biochemical indices, whole-body proximate composition, serum biochemical indices, and fatty acid composition (hepatopancreas) of common carp (Cyprinus carpio), an 8-week study was carried out. Juveniles were fed diets with different inclusion of BSFLF levels (0%, 10%, and 20%) in a recirculating aquaculture system, with each diet randomly assigned to a triplicate group of 90 fish (10 fish per tank), with an initial weight of 119.35 ± 30.97 g stocked into 250 L tanks. The study found that increasing dietary frass led to increased growth rates, relative growth rate, weight gain, and protein efficiency ratios, and to decreased feed conversion ratios. Within both total phospholipid and triglyceride fatty acid compositions, the 20% dietary frass increased proportions of saturated and omega-3 fatty acids while decreased the oleic acid (C18:1n9) proportion. To sum up, the use of BSFLF, notably at a 20% inclusion level, as a source of dietary protein has the potential to significantly improve the overall productivity of common carp. Full article

Spent coffee grounds (SCGs) represent a globally abundant agro-industrial byproduct with underexploited potential in circular bioeconomy applications. This study investigates the extraction, characterization and functional integration of SCG protein concentrate into aquafeed formulations for common carp (Cyprinus carpio). Protein was recovered through alkaline extraction followed by isoelectric precipitation, yielding a concentrate incorporated at 5% into a mixed plant and fishmeal diet produced by cold pelletizing. Compositional analysis performed by FT-NIR showed 33.6% crude protein, 7.24% lipids and 7.85% fiber, while ICP-OES confirmed substantial levels of essential minerals including Ca, P, K and Mg (15.3, 8.4, 10.4 and 2.3 g/kg). SCGs contributed bioactive compounds, with total polyphenols reaching 1.521 ± 0.065 mg GAE/g DM and an antioxidant capacity of 3.35 ± 0.03 mg TE/g DM. Pellets exhibited high water stability (91.8% retention after 30 min), and a short-term feeding test demonstrated strong acceptance by juvenile carp (91.2 ± 2.1%) consumption. Residual caffeine levels remained low (3.5 mg per g dry weight) and within safe exposure margins for freshwater fish. The results demonstrate the technical feasibility of incorporating SCG protein concentrate into compound aquafeeds without compromising pellet integrity or short-term palatability, while increasing feed-level antioxidant potential. However, the findings represent a proof-of-concept evaluation. Further research involving longer-term feeding trials, digestibility assessment, and amino acid profiling of complete diets is required to validate nutritional performance and optimize inclusion strategies for sustainable aquaculture. Full article

Genomic prediction has been increasingly applied in aquaculture selective breeding; however, systematic evaluations of prediction accuracy across multiple aquaculture species and analytical methods under a unified and comparable framework remain limited. In this study, we conducted a comprehensive comparative assessment of genomic prediction performance across four representative aquaculture species, including Atlantic salmon (Salmo salar), gilthead sea bream (Sparus aurata), common carp (Cyprinus carpio), and rainbow trout (Oncorhynchus mykiss), using ten genomic prediction models including GBLUP, Bayesian and machine learning methods. Prediction accuracy varied widely among species and models, ranging from 0.49 to 0.85, and was strongly associated with trait heritability. High-heritability traits consistently achieved higher prediction accuracies, with rainbow trout and common carp exhibiting the best overall performance (0.75–0.83 and 0.73–0.85, respectively), whereas Atlantic salmon and gilthead sea bream showed lower and more variable accuracies (0.49–0.61 and 0.49–0.66). No single model performed optimally across all species. Machine learning-based approaches achieved the highest prediction accuracy in specific cases but exhibited pronounced species-dependent variability, while GBLUP provided stable and well-calibrated predictions with consistently low bias. Incremental SNP feature selection further improved prediction accuracy by 2.8–4.2% in three species using only 0.54–9.64% of the available markers, whereas no improvement was observed for a low-heritability trait. These results show that genomic prediction performance is highly context-dependent and underscores the importance of jointly considering trait genetic architecture, population characteristics, model choice, and marker selection when optimizing genomic selection strategies in aquaculture breeding programs. Full article

Polycyclic aromatic hydrocarbons (PAHs) can enter water bodies and bioaccumulate in fish, leading to biomagnification; therefore, their monitoring is necessary. Passive sampling is easy to handle and shows potential for this purpose. However, studies in vivo are scarce, and kinetic parameters governing analyte partitioning between tissue and samplers remain poorly characterized. In this study, the silicone rubber membranes (SRMs) were exposed to fish fillet from common carp (Cyprinus carpio) to determine bioaccumulation parameters based on dissipation modelling using performance reference compounds (PRCs). The SRM was implanted in vivo in fish, and the dissipated PRCs were measured and applied to a mono-compartmental model. The results in fish fillet showed a pseudo-first kinetic order, and the plateau was attained at a time > 30 h. However, the equilibrium may not be ensured because of the low lipid fraction (fl) in fish (4.5%), which could lead to a local saturation of the tissue in contact with the SRM. The ratio between elimination and uptake constants (K_e/K_u) showed faster PAHs–SRM sorption than PAHs-fish tissue sorption (200 times); thus, fish with low fl will lead to faster SRM sorption. By contrast, in fish with higher fl, the long-term exposures will be necessary. The percentage of released deuterated PAHs from SRM during in vivo fish exposure was 1.6 times higher than that observed in the fish fillet, indicating an active clearance process. Therefore, during implantation, the rate of clearance and the fl should be considered to ensure detectable levels for applying the integrative equation based on dissipation modelling. Full article

This study investigated the efficacy of two value-added products derived from silkworm excrement—a concentrated extract (SCE, 20:1) and sodium copper chlorophyllin (SCC)—as functional feed additives for common carp. Diets supplemented with 0.5% SCE, 1.0% SCE, or 0.1% SCC were compared to a basal control. The results revealed a distinct dose-dependent effect for SCE: 0.5% SCE was safe, while 1.0% SCE impaired growth, feed efficiency, and digestive enzyme activity. Both SCE and SCC significantly enhanced lipid metabolism, reducing hepatic lipid deposition and improving serum lipid profiles, albeit through distinct molecular pathways—SCC primarily stimulated catabolism, whereas SCE comprehensively regulated both synthesis and breakdown. Furthermore, SCE demonstrated superior, multi-targeted immunomodulatory capacity by favorably regulating inflammatory cytokine expression, an effect not observed with SCC. Although both additives boosted systemic antioxidant capacity, their specific patterns of enzyme activity and gene expression differed. In conclusion, SCE offers broad-spectrum, synergistic benefits for health modulation, while SCC provides specific, stable bioactivity, highlighting the importance of selecting the appropriate additive form based on desired functional outcomes in aquaculture. Full article