Search

Asian catfish, Clarias magur (Hamilton, 1822), known as magur, is a popular food fish in Asian countries because of its high nutritional and medicinal value. Aquaculture of magur is constrained by non‐availability of seed due to very high mortality during the early larval stages. The strategies to enhance the larval survival during the early stages could be a major step in enhancing the seed production of this species. So, the aim of the present study was to assess the effect of highly unsaturated fatty acids (HUFA)‐ and vitamin C‐enriched infusoria on the growth and survival of C. magur larvae. Eight‐day‐old larvae with an average weight of 3 mg and length of 5 mm were stocked in plastic crates (30 x 20 x 18 cm) each containing 40 litres of water. A total of 16 crates were used in experiment and in each crate 100 larvae were stocked. The larvae were fed three times daily with HUFA, vitamin C, both HUFA and vitamin C and un‐enriched infusoria @ 9–10 numbers per ml of rearing water for 30 days in four different treatment groups. The proximate analysis of different enriched and un‐enriched infusoria showed the highest (84.25%) moisture content in HUFA‐enriched Infusoria, and the highest percentage of crude protein (9.80%), crude lipid (3.50%) and ash content (0.78%) in vitamin C‐enriched Infusoria. The survivability analysis showed the highest survival in the treatment group fed with HUFA‐enriched infusoria (49.25%) and the lowest in the control group (18.25%). This indicates that the enrichment of infusoria with HUFA could increase the survival rate significantly. The highest body weight gain (55.75 mg) was observed in HUFA‐enriched group but not significantly different from the control group. The study indicates that the enrichment of infusoria with HUFA have a significant influence on larval survival. [ABSTRACT FROM AUTHOR]

Vitamin C (VC) is a necessary nutrient for normal fish physiology and immunity. Therefore, A 60‐day feeding trial was designed to evaluate the dietary VC requirements of silver carp (Hypophthalmichthys molitrix). Six isocaloric and isonitrogenous diets were formulated by incorporation of VC at 0, 50, 100, 200, 400 and 800 mg kg−1 levels and the analysed VC content in diet was 5.7, 51.1, 95.3, 191.6, 370.7 and 757.5 mg kg−1 respectively. At the trial termination, VC supplementation significantly enhanced the growth and feed utilization. The highest values for whole body crude protein were recorded at 95.3 and 191.6 mg kg−1 of VC. In comparison to the basal diet, VC supplementation improved (p < 0.05) the whole body crude fat. Dietary VC had a dose‐dependent effect on the white blood cell count and haematocrit. A significant increase in the alkaline phosphatase activity was recorded for fish fed 5.7 to 95.3 mg kg−1 of VC, attaining a constant value afterwards (95.3–757.5 mg kg−1 of VC). In comparison, dietary VC decreased (p < 0.05) the aspartate aminotransferase and alanine aminotransferase activities. Similarly, the glucose content also decreased significantly from 5.7 to 95.3 mg kg−1 of VC and became constant thereafter. Dietary VC supplementation significantly affected the antioxidant enzyme activities. The liver VC content showed a dose‐dependent relation, where the VC content increased with the increase in VC supplementation reaching the highest value at 757.5 mg kg−1. Moreover, VC‐fed fish showed an increased (p < 0.05) survival against Aeromonas hydrophila challenge. On the basis of broken‐line regression, the optimum dietary VC requirement of H. molitrix for weight gain% and liver VC content is 61.31 and 241.13 mg kg−1 respectively. [ABSTRACT FROM AUTHOR]

As a micronutrient, vitamin C plays an important role in growth and immunity of fish, but the effects of vitamin C on Pampus argenteus were still unclear. Here, we added vitamin C with different concentrations (0, 350, 1050, 2100 and 4200 mg/kg) to the basic diet, and the optimal concentration of vitamin C was screened out as 1050 mg/kg through the growth indicators, antioxidant enzyme activities (SOD, CAT, GSH‐PX and MDA) and the expression of four immune‐related genes (IL‐2, IL‐3, IL‐17 and IL‐18). After feeding dietary vitamin C supplementation with optimal concentration for 4 weeks, 80 ml/t formaldehyde was used to damage the immune system of fish. Then, the activities of the antioxidant enzymes and immune‐related genes were tested to find out the protective effects of vitamin C on the immune system. The results showed that the activity of CAT, SOD and GSH‐PX increased, while the MDA content decreased. At the molecular level, the expression of IL‐2 and IL‐3 genes increased, but the expression of IL‐17 and IL‐18 genes was inhibited. These findings suggested that the dietary vitamin C supplementation improved fish growth, alleviated the stress reaction caused by formaldehyde treatment and improved the immunity of P. argenteus. [ABSTRACT FROM AUTHOR]

Microalgae are one of the most important sources of natural bioactive compounds, especially those revealing antioxidant activity such as β‐carotene. Thus, this study was to compare the effects of dietary Vitamin C (L‐ascorbic acid) or Vitamin E (α‐tocopherol) with β‐carotene extracted from Arthrospira platensis on Nile tilapia (Oreochromis niloticus) on growth, feed utilization, blood indices, antioxidant activity, non‐specific immunological indices and related gene expression. Three hundred and sixty apparent healthy Nile tilapia (5.80 ± 0.286 g) were randomly distributed into four groups. Four isonitrogenous and isoenergetic diets were performed. A control diet was compared against three experimental diets supplemented with Vitamin C (0.5 mg kg−1 diet), Vitamin E (1 g kg−1 diet) or β‐carotene (0.5 g kg−1 diet) for 10 weeks. According to the results, there was no significant difference in feed intake (p > 0.05) between experimental diets. Dietary Vitamins C and E and β‐carotene significantly (p < 0.05) enhanced the weight gain, final body weight, protein efficiency ratio, specific growth rate and apparent protein utilization in all groups, whereas the best FCR (p = 0.017) and the highest weight gain (p = 0.007) were detected in the β‐carotene diet. Fish survival rates differed significantly (p < 0.05) amongst treatments, whilst fish fed a diet supplemented with β‐carotene recorded the highest survival rate. The supplemental diet with β‐carotene boosted the values of the biochemical and haematological parameters (p < 0.05) compared with the control diet. The activities of catalase, superoxide dismutase (SOD) and total antioxidant capacity (T‐AOC) in the liver (p = 0.0560; p = 0.0032; p = 0.0353 respectively) and tilapia muscles were higher in fish fed either β‐carotene or Vitamin E (p = 0.0579; p = 0.1494; p = 0.2145 respectively) than other groups. The highest values of SOD, CAT and immune globulin M‐2 gene expression (p < 0.05) were found in fish fed a diet enriched with β‐carotene. These results suggested that the dietary incorporation of β‐carotene had a superior impact on growth performance, haemato‐biochemical and immune‐oxidative stress biomarkers in addition to the associated gene expression of Oreochromis niloticus. [ABSTRACT FROM AUTHOR]

This study aimed to assess the ameliorative dietary effect of vitamin‐C against sodium fluoride (NaF)‐induced toxicity on growth and haemato‐biochemical parameters in Amur carp. A total of 150 fish (average body weight 169 ± 0.69 g) were randomly distributed into five groups (with three triplicates) including G1 (control); G2 (NaF exposure @100 ppm); G3 (vitamin‐C supplemented diet @100 ppm); G4 (both NaF exposure @100 ppm and vitamin‐C supplemented diet @100 ppm) and G5 (NaF exposure @100 ppm for 60 days and then vitamin‐C supplemented diet @200 ppm for last 30 days). Results revealed that growth and hemato‐biochemical profile was best in G3 in comparison with G1, whereas groups G2, G4 and G5 have shown retarded growth, a decrease in Hb, TEC, PCV, MCV, MCH and MCHC. Serum‐biochemical parameters were found optimum in G3 as compared with G1 and in groups of G2, G4 and G5, total serum protein, albumin, globulin, glucose, and triglyceride levels decreased significantly, whereas creatinine, AST and ALT levels increased significantly. In G4, toxicity was less severe in comparison with G2, whereas in G5, after the dietary supplementary of vitamin‐C, parameters have shown a bend towards the normal values. Thus, it can be concluded that vitamin‐C has ameliorative action against fluoride toxicity in fish. [ABSTRACT FROM AUTHOR]

In this study, we used enzymatic chemistry, histology and molecular biology to systematically study the effects of vitamin C (VC) in feed on haemocyte number and haemolymph activity in Cherax quadricarinatus. We also compared the effects of VC on the number of haemocytes, the haemocyte microstructure and the ultrastructure of C. quadricarinatus haemocytes after White spot syndrome virus (WSSV) infection. When feed was supplemented with 800 mg/kg VC (C5 group), the number of haemocytes increased by 42.26% compared with the control group (C1 group); and the haemolymph of the C5 group had the highest agglutination activity and anti‐bacterial rate, which was significantly higher than that of the C1 group (p < 0.05). WSSV infection significantly reduced the total number of haemocytes, and the number of haemocytes was significantly higher in the C1 group than in the than C5 (p < 0.05) for up to 96 h. At 96 h, transmission electron microscopy revealed crushed perinuclear material, cell lysis, and damaged cell membranes in the C1 group, and large apparently damaged particles in the C5 group, with clear cell swelling and small particles, although the cell structure was intact. These results showed that VC enhanced the immune function of crayfish to a certain extent, maintained the integrity of the haemocyte structure and conferred an immunoprotective effect on C. quadricarinatus against WSSV infection. [ABSTRACT FROM AUTHOR]

A 60-day feeding experiment was conducted to evaluate the dietary effect of vitamin C on non-specific immunity and stress responses in striped catfish, Pangasianodon hypophthalmus juveniles with the average body weight of 3.23 ± 0.01 g to 3.38 ± 0.01 g. Seven graded levels of diets supplemented with 0, 17.5, 35, 70, 175, 350 and 700 mg vitamin C/kg diet as L-ascorbyl-2-polyphosphate were fed to fish in triplicates group. At the end of the experiment, fish fed vitamin C diet had significantly higher responses for nitroblue tetrazolium (NBT), serum lysozyme, phagocytic activities and lowest activities for superoxide dismutase (SOD) and catalase (p<0.05) under both pre- and post-challenge conditions with Aeromonas hydrophila. After a challenge, the percentage survival of fish fed vitamin C diet was improved than those of fish fed vitamin C-deficient diet. The overall results of the present study indicated that dietary vitamin C had a significant influence on immunity and stress mitigation in P. hypophthalmus juveniles. However, the highest positive response values obtained for immune and stress parameters in fish lies within the range of 350 to 700 mg ascorbic acid (AA) kg-1 of the diet. From the present experiment, it may be concluded that the dietary vitamin C supplementation at the level of 350 to 700 mg AA kg-1 of the diet would be optimal for influencing the immunity and stress responses in P. hypophthalmus juveniles. [ABSTRACT FROM AUTHOR]

Systematic granulomatosis is a chronic disease that affects the majority of farmed meagre (A. regius). Nutritional imbalances and overcrowding can increase the risk to suffer oxidative stress, and consequently, impact the incidence of granulomatosis. In order to evaluate this, juvenile meagre were fed five isolipidic (16.7%) and isoproteic (49.6%) fish meal and fish oil‐based feeds prepared by adding different levels of vitamin C, minerals (Mn, Zn, Se) with constant vitamin E and K (300 and 35 mg/kg respectively): Diet KEC (100 mg/kg C), Diet KEC+Mn/Zn/Se (100 mg/kg C, 40 mg/kg Mn, 200 mg/kg Zn, 1.5 mg/kg Se), Diet KECC (600 mg/kg C), Diet KECCC (1200 mg/kg C), Diet KECCCC (3200 mg/kg C). All diets were tested at 3.20 kg/m3, but diets KECC and KECCCC were also tested at 6.20 kg/m3. Growth performance was only affected by stocking density, being lower at high density. The percentage of fish with granulomas was significantly lower in fish fed with the highest dietary vitamin C contents (KECCC and KECCCC) at low density. TBARS content was correlated with the percentage of granulomas in the liver (R2 = 0.9439, y = 0.003x − 0.1242) denoting the involvement of an imbalance oxidative status in the appearance of granulomas. The present results show that high levels of vitamin C (1200–3200 mg/kg C) and low stock density (3.20 kg/m3) favours the growth of juvenile meagre, reducing the lipid peroxidation indicators and decreasing the incidence of granulomas, which confirms that this pathology is mostly triggered by the deficiency of antioxidant nutrients, particularly vitamin C. [ABSTRACT FROM AUTHOR]

Adult koi carp (Cyprinus carpio L.) were fed with feed supplemented with vitamin C at 200 mg/kg feed (T1), 400 mg/kg feed (T2) and 600 mg/kg feed (T3), and vitamin E at 200 mg/kg feed (T4), 400 mg/kg feed (T5) and 600 mg/kg feed (T6) at ad libitum for 60 days. Control (without vitamin inclusion) was also maintained. Observations were made on the growth performance, GSI and biochemical composition of gonads such as crude protein, crude fat, cholesterol and carotenoid once in 15 days. At the end of the experiment, fertilization was done to record the fertilization and hatching rate. The difference in the values was noticed among the male and female koi carp. Fish supplemented with vitamin E at 200 mg/kg feeexhibited higher growth in both male and female fish, and the fertilization rate and hatching rate were also higher in that group, and the values were significantly different (p < 0.05) and showed linear and quadratic trends. Inclusion of vitamin C at 600 mg/kg feed had shown higher lipid and carotenoid contents of female koi carp (p<0.05). Hence, the results revealed that supplementing vitamin C and E in the diet is necessary for the successful reproduction of koi carp. [ABSTRACT FROM AUTHOR]