Search Results (344)

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

The present study aimed to evaluate whether commonly used condition indices reflect parasite load and bacterial colonization in juvenile Cyprinus carpio under natural environmental conditions in the Lower Danube River. A total of 260 specimens were examined for parasitological, microbiological, and biometric parameters, including 20 individuals analyzed for bacterial communities. Twenty-three parasite taxa belonging to eight major taxonomic groups were identified. Ectoparasites were found on the gills, skin, and fins, with monogeneans and ciliates, notably Dactylogyrus ssp. and Trichodina ssp., representing the dominant groups. Infection intensity was generally low to moderate, and histopathological examination revealed only mild epithelial alterations, including focal hemorrhage and mucus hypersecretion in more heavily infected individuals. Microbiological analysis identified six bacterial taxa associated with the skin, with Aeromonas hydrophila being the most frequently detected species. Correlation analyses showed no significant relationships between parasite abundance and condition indices (Fulton’s K, Le Cren’s Kn, scaled mass index, and BMI), although a slight reduction in Fulton’s K was observed in infected individuals. These findings indicate a stable host–parasite–microbiota equilibrium under natural environmental conditions. The results provide baseline ecological data that contribute to understanding fish health dynamics in the Lower Danube River and may support future monitoring and management strategies. 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

The aim of this study was to evaluate the effects of incorporating Black Soldier Fly Meal (BSFLM) into the diet of two-year-old carp on growth and health status. Four concentrations of BSFLM were tested, T1-0% (control), T2-10%, T3-20%, and T4-30%, in common carp with an initial body weight of 112.06 ± 3.86 g over a 12-week feeding period. The results showed that final weight and weight gain were 17.3% (349.15 g) and 23% (233.6 g) higher in the T4 group compared to the control (298.63 g and 189.79 g, respectively). Flesh composition showed no significant changes. Hematological variations were insignificant. Oxidative stress assessment revealed increased activities of antioxidant enzymes (SOD, CAT, and GPx) alongside reduced lipid peroxidation. The counts of anaerobic microorganisms and Enterobacteriaceae in intestine increased linearly in BSFLM groups. Histological examination showed normal intestinal and hepatopancreatic morphology in the 10% and 20% BSFLM groups (T2 and T3). In contrast, the 30% inclusion level (T4) was associated with hepatocellular vacuolization and alterations in villus architecture. In two-year-old carp, dietary BSFLM induced dose-dependent responses, whereby higher inclusion levels supported weight gain but adversely affected the morphological integrity of the intestine and hepatopancreas. Full article

This research was conducted to evaluate the impacts of pomegranate (Punica granatum L) peel extract (PPE) on the mold growth and moisture content in pellet feeds, as well as the biochemical indicators in tissues and organs of fish. Firstly, six types of pellet feeds were formulated by adding 0% or 0.5% of pomegranate peel powder (PP), petroleum ether extract (PEE), ethyl acetate extract (EAE), ethanol extract (EE), or aqueous extract (AQE) of PP. Moisture content was determined by air-drying 10 g of wet pellet feed from each treatment at 60 °C for 48 h in uniform-sized Petri dishes. Mold growth was evaluated by homogenizing 15 g of 12-week stored pellet feed with 15 mL of purified water, incubating at 25 °C for 4 days, and recording mold growth. The results indicated that PP, PEE, EE, and AQE reduced the mold growth in pellet feeds (p < 0.05). PP, EAE, EE, and AQE increased the moisture content in pellet feeds. Among all additives, EE has the strongest effects on the mold growth and moisture content in feeds (p < 0.05). According to regression analysis of mold and moisture levels, the optimal EE supplementation levels in pellet feeds were evaluated to be 1.284% and 1.485%, respectively. Then, 420 carp (Cyprinus carpio var. Jian, mean initial weight 12.01 ± 0.53 g) were fed diets formulated with EE at graded inclusion levels (0, 0.3, 0.6, 0.9, 1.2, 1.5, and 1.8%) over a 15-day period. The findings indicated that dietary EE improved the digestive and absorptive function in carp (p < 0.05), and this improvement was closely correlated with the upregulated activities of digestive and absorptive enzymes and the strengthened antioxidant capability in carp’s digestive tissues. Regression analysis of feed intake rate indicated that the optimal EE level suitable for carp is 0.906%. Furthermore, dietary EE enhanced the respiratory capacity by improving functional metabolic enzyme activity and antioxidant defense in the respiration-related tissues and organs of fish (p < 0.05). In summary, supplement EE increases the moisture content, inhibits the mold growth in pellet feeds, and improves the respiratory, digestive, and absorptive functions in fish, providing a valuable insight for PEE use as a naturally functional raw material in fish feeds. 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

Sapanca Lake is a tectonic freshwater lake ecosystem whose water balance and ecological integrity are increasingly threatened by urbanization, pollution, climate change, and declining water levels. To assess recent changes in the fish community, length–weight relationships (LWRs), condition factors (CFs), sex ratios (F/M), and standing stock biomass estimates were determined for eight fish species (Blicca bjoerkna, Scardinius erythrophthalmus, Carassius gibelio, Esox lucius, Silurus glanis, Perca fluviatilis, Abramis brama and Cyprinus carpio) sampled between December 2024 and April 2025. According to standing stock biomass assessments, Cyprinus carpio showed the highest biomass (297.67 tons), while Abramis brama had the lowest (22.72 tons). Most species showed positive allometric growth (b > 3), suggesting generally favorable feeding conditions. In contrast, the main predatory species, E. lucius (b = 2.89) and Silurus glanis (b = 0.21), exhibited negative allometric growth, likely due to limitations in food availability and prey abundance. The CF values were generally >1, indicating good physiological status; however, lower CF values in A. brama (1.18) and B. bjoerkna (1.19) suggest species-specific ecological limitations. Sex ratio analysis revealed pronounced female dominance across species, ranging from complete female dominance (F/M = 1/0) in Carassius gibelio to a female-biased ratio of 1/0.04 in Scardinius erythrophthalmus, likely driven by seasonal sampling effects, sex-specific behavior, and species-specific reproductive strategies. Overall, the results indicate increasing trophic imbalance and ecological stress in Sapanca Lake, emphasizing the need for standing stock biomass assessments and ecosystem-focused fisheries management in tectonic lakes under hydrological pressure. 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

The study aimed to assess the influence of two packaging methods (under vacuum, VP vs. air, AP) on the quality of fish balls from carp (Cyprinus carpio) stored at +4 °C up to 14 days after preparation. The air-packed and vacuum-packed fish balls were analyzed for physicochemical parameters, microbiological status, and sensory characteristics. The packaging method and storage time interaction significantly (p < 0.05) affected the acid value (AV) and peroxide value (PV), as well as the thiobarbituric acid reactive substance index (TBARS), with lower values of these parameters observed in vacuum-packed samples at 7 d (AV, PV, TBARS), 9 d (TBARS), 12 d (PV) and 14 d (TBARS) of storage. Moreover, vacuum packaging helped maintain a beneficial oil absorption and pH, and partially slowed down the occurrence of undesirable changes in color, i.e., the decrease in redness of semi-raw fish balls or increase in yellowness of deep-fried products. Based on the overall quality values, the air-packed fish balls were sensory acceptable for up to 9 days, while the vacuum-packed fish balls were acceptable up to 12 d. The bacterial counts (total viable counts—TVC, psychrotrophic bacterial counts—PBC, total staphylococcal counts—TSC, sulfite-producing bacteria counts—SPBC, and lactic acid bacteria counts—LABC) increased during storage. Although the rate and pattern of growth varied depending on the packaging, fish balls maintained the recommended microbiological quality throughout the entire storage period. The VP method inhibited the growth of TVC, PBC, TSC, and SPBC relative to the AP method, while the VP method showed a higher increase in LABC. The results indicated that vacuum packaging appears to be an effective approach to prolong the shelf life of fish balls made from carp. Additionally, developing this convenient food product could be a valuable strategy to enhance consumer acceptance and promote the use of widely farmed carp species. Full article

Distant hybridization induces genomic instability in offspring, driving the occurrence of gene recombination and mutation. Analysis of the genomic genetic composition can be used to infer the genetic evolutionary relationships between species. Based on the improved diploid carp (IDC) and the improved diploid scattered mirror carp (IDMC) lineages derived from distant hybridization between female common carp and male blunt snout bream, this study analyzed the genetic variation in their mitochondrial genomes to investigate the impact of distant hybridization on mitochondrial DNA (mtDNA) structural variation. Analysis of complete mitochondrial genome sequence structure and composition revealed subtle structural divergence across generations in both the IDC and IDMC lineages. Analysis of the protein-coding gene sequence structure demonstrated mitochondrial genome structure instability in nascent hybrid diploid lineages. Yet, subsequent self-crossing significantly narrowed the range of structural variation within each lineage. Furthermore, analysis of the genetic variation in the mitochondrial genome sequence structure revealed that paternal base insertions occurred in both F₁ lineages, accompanied by mutations predominantly consistent with those in crucian carp. The results of this study also indicated that the strictness of the paternal mtDNA elimination mechanism varied significantly among polymorphic individuals across different generations of the hybrid lineages, reflecting the randomness of paternal leakage. Full article