This study investigated the effects of incorporating grape pomace (GP) into fish diets on the growth performance, physiological parameters, and biochemical composition of carp (Cyprinus carpio L.). A total of 180 carp, with an average initial weight of 65 g, were reared in a recirculating aquaculture system (RAS). They were divided into a control group (C), fed with a diet containing 0% GP, and two experimental groups (V1 and V2), fed with diets containing 5% and 10% GP, respectively. The experiment lasted for eight weeks. Results revealed that most growth parameters were not significantly affected by GP inclusion, except for a notable difference in the hepatosomatic index (HSI), indicating an impact on liver size relative to body weight. The biochemical analysis of carp meat showed significant differences in moisture, protein, fat, collagen, and salt content between the control and experimental groups. Furthermore, the oxidative status assessment indicated that GP supplementation modulates oxidative stress and lipid peroxidation pathways in carp, enhancing their antioxidant defenses and overall health. Microbiological examination of the carp intestinal content showed that GP inclusion in fish diets influenced microbial parameters, particularly affecting the abundance of aerobic germs and Enterobacteriaceae.

This study investigates the influence of internal factors on growth dynamics in four Cyprinus carpio varieties, three Romanian strains (Frăsinet, Ineu, and Podu Iloaiei) and the Koi variety. Fish were measured for total length, maximum height, and weight at four ontogenic stages, namely 7 days post-hatch, 3 months (0⁺), 18 months old (1⁺), and 36 months (2⁺). Weight Gain (WG), Specific Growth Rate (SGR), Relative Growth Rate (RGR), Fulton’s condition factor, and the profile index were calculated and analyzed. Results revealed significant intervariety differences in growth performance and physiological condition across life stages. At the 2⁺ stage, Podu Iloaiei exhibited the highest WG (849.73 ± 4.09 g), while Koi showed the lowest (403.99 ± 14.21 g). Koi demonstrated a unique growth pattern, with the highest SGR (0.18 ± 0.00% day⁻¹) and RGR (0.98 ± 0.05 g day⁻¹) at the 2⁺ stage. Fulton’s condition factor varied markedly, with Frăsinet showing the highest value at 7 days post-hatch (149.57 ± 17.485) and Koi the lowest at the 1⁺ stage (0.63 ± 0.011). The profile index decreased with age in all varieties, with Podu Iloaiei showing the most dramatic change from 4.22 ± 0.149 at 7 days to 2.18 ± 0.004 at 2⁺. These findings highlight the complex interplay between genetic and developmental factors in carp varieties, offering new insights for tailored breeding programs and aquaculture practices.

The optimization of broodstock nutrition remains a critical challenge in sturgeon aquaculture. This study investigated the effects of wheatgrass juice (WGJ) supplementation of sterlet (Acipenser ruthenus) broodstock on reproductive performance, larval quality, hematological profile and oxidative status. Female sterlets were randomly assigned to three groups: control diet (V1), WGJ-supplemented diet (V2, 4 % inclusion), both (V1 and V2) hormonally stimulated and saline solution (V3) without hormonal stimulation. WGJ's chemical composition revealed substantial levels of bioactive compounds, including chlorophyll (a: 0.936 ± 0.01, b: 0.329 ± 0.01 mg/mL fw), carotenoids (0.167 ± 0.01 mg/mL fw), proteins (1.205 ± 0.04 mg PSB/mL fw), flavonoids (7.381 ± 0.31 mg/mL fw), and polyphenols (2.963 ± 0.05 mg/mL fw). WGJ supplementation significantly enhanced reproductive parameters, with V2 showing higher egg production (0.23 ± 0.03 kg vs. 0.13 ± 0.01 kg) and gonadosomatic index (14.48 ± 1.73 vs. 8.05 ± 0.51) compared to V1. Larvae from WGJ-supplemented females exhibited significantly improved length (10.9 ± 0.3 cm vs. 9.8 ± 0.14 cm, p < 0.001) and weight parameters. Analysis of oxidative stress markers revealed tissue-specific modulation of antioxidant systems, with WGJ supplementation reducing malondialdehyde levels across tissues (muscle: 1.061 ± 0.075 vs. 1.888 ± 0.105 nM/mg protein, p < 0.0001) and enhancing antioxidant enzyme activities. Hematological parameters remained within physiological ranges, with reduced neutrophil counts in the WGJ group suggesting potential immunomodulatory effects. These findings establish WGJ as a promising functional feed additive for enhancing reproductive performance in sterlet aquaculture, while maintaining optimal physiological status through improved antioxidant defense mechanisms.

This study investigates the impact of including sorghum in the diet of the common carp (Cyprinus carpio) on its growth, blood parameters, meat composition, intestinal microbiota, and oxidative stress. Experimental diets with varying sorghum content (0%—V0 or control, 10%—V1, 20%—V2, and 30%—V3) were administered to carp weighing 43 g initially. Notably, in the 30% variant, sorghum entirely replaced corn and barley in the diet. Chemical analysis of sorghum unveiled a protein content of 14% and a fat content of 3.9%. Sorghum inclusion led to a decline in final body weight and weight gain, particularly notable in the V3 group with 30% sorghum. However, other physiological parameters, such as feed conversion ratio, specific growth rate, and organ indices, remained unaffected. Protein and salt content in carp flesh increased with higher sorghum inclusion levels, while hematological parameters showed minimal variations. Analysis of the intestinal microbiota revealed increases in both aerobic and anaerobic bacterial populations with sorghum inclusion. Furthermore, sorghum concentration inversely correlated with glutathione levels and positively correlated with malondialdehyde content, indicating a disruption of antioxidant defense mechanisms and elevated oxidative stress.

This study examined the effects of dietary aniseed, thyme, and basil essential oils (EOs) on growth, health, and tissue integrity of common carp (Cyprinus carpio) reared in a recirculating aquaculture system (RAS). Juvenile carp (102 ± 2.8 g) were fed for 12 weeks four isonitrogenous diets: a control and three diets supplemented with 0.2% aniseed (V1), thyme (V2), or basil (V3) oils. Growth performance was not significantly affected (p > 0.05). Flesh biochemical composition improved, with higher protein in V1 (17.85 ± 0.22%) and lower fat in V3 (1.78 ± 0.21%) compared to the control. Hematological parameters and antioxidant enzymes (SOD, CAT, GPx) indicated enhanced immune and oxidative status, while MDA (malondialdehyde) levels decreased. SOD activity increased in treated groups, reaching 4.329 U mg⁻¹ protein in muscle and 4.908 U mg⁻¹ protein in liver in V2, compared to 2.775–3.677 U mg⁻¹ protein (muscle) and 3.508–4.349 U mg⁻¹ protein (liver) in controls. CAT activity was highest in the same group 57.045 U mg⁻¹ protein versus 31.403 U mg⁻¹ protein in controls. Microbiological assessment revealed reduced total aerobic bacteria and Enterobacteriaceae counts in EO-fed fish. Histological analysis showed healthier hepatic and intestinal structures, reduced vacuolation, intact epithelium, and abundant goblet cells in EO-treated groups.

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.