کوروش سروی مغانلو

Environmental pollution by heavy metals is considered a serious threat to aquatic ecosystems, and their increase can affect the life cycle and biological reserves of many zooplankton species such as Artemia. Therefore, in the present study, the effects of heavy metal cadmium on the growth, survival, digestive enzymes activity, and some reproductive characteristics of Artemia urmiana were evaluated. For this purpose, the LC50 of cadmium chloride was determined for 24 and 72 hours in the nauplii and adult stages using probit statistical analysis. The average LC50 of 72 hours was used to investigate the chronic toxicity and nauplii was cultured in 3 treatments including the control group, 10% LC50 and 20% LC50 for 21 days. The results showed that different concentrations of cadmium chloride decreased the growth of A. urmiana on 17 and 21 days (p<0.05). Also, a decrease in survival rate was observed on all rearing days and the highest decrease (28.9%) was observed in the 20% LC50 group (p<0.05). The activity of digestive enzymes was not affected by cadmium chloride (p>0.05), however, the activity of alkaline protease and alpha-amylase increased and the activity of lipase decreased with an increase in cadmium chloride concentration. Also, reproductive indices including, the percentage of cyst formation and the number of offspring per reproduction were not affected by the concentration of cadmium chloride (p>0.05). However, the frequency of reproduction and the total number of births decreased and the number of daily births increased (p<0.05). In conclusion, cadmium chloride led to a decrease in growth and survival and changes in the digestive enzyme activity and reproductive indices of A. urmiana. Therefore, more attention should be paid in relation to how to manage the disposal of polluted wastes.

The present study was carried out to investigate the effect of different dietary levels of fermented canola meal by the Bacillus isolated from Caspian Sea sediments on growth and nutritional indices, proximate body composition, and digestive enzymes activity of Nile tilapia fingerlings. A total of 225 fry fish with an average weight of 1.90±0.05 g were fed with five different experimental diets including treatment 1: a diet without fermented canola, treatment 2: a diet containing 12.5% ​fermented canola, treatment 3: a diet containing 25% fermented canola, treatment 4: a diet containing 37.5% fermented canola, and treatment 5: a diet containing 50% fermented canola for 8 weeks. Results revealed that the growth and nutrition indices did not significantly differ among various experimental groups (p>0.05). Proximate analyses of the body composition showed that the protein contents of treatments 2, 3, and 4, the lipid and moisture contents of treatments 3, 4, and 5, and also the ash contents of treatments 4 and 5 were increased compared to the control group (p<0.05). Also, the results of digestive enzymes activity showed that the alkaline protease activity of treatments 3 and 4, lipase activity of treatments 2 and 3 and also the alpha amylase activity of treatment 3 were increased in comparison with the control group (p<0.05). In general, it was concluded that incorporating 50% of fermented canola did not affect growth performance and nutritional indices in Nile tilapia fingerlings.

Regarding the use of cypermethrin insecticide in agriculture in West Azerbaijan and the possibility of its entry into the Urmia Lake, the present study was conducted to investigate the effect of cypermethrin on growth, survival, and some physiological parameters of Artemia urmiana. For this purpose, the LC50 of cypermethrin for 24, 48, and 96 hours in the nauplii, post-larva, and adult stages were obtained using the probit test. The average LC50 of 96 hours was used to study the effect of chronic toxicity. Then, the Naplii was cultured in 4 treatments including the control group, 25% LC50, 50% LC50, and 100% LC50 for 15 days. At the end of the experiment, growth, survival, antioxidant enzymes activity, and digestive enzymes activity of the whole body were evaluated. The results showed that different concentrations of cypermethrin decreased the growth and survival of A. urmiana (p<0.05) and the amount of this decrease depended on the age of Artemia and the exposure duration. The highest decrease in growth and survival of different life stages of A. urmiana was observed in the 100% LC50 group. The results of antioxidant enzymes activity showed that cypermethrin decreased the levels of superoxide dismutase, catalase, and malondialdehyde (p<0.05), but there was no change in the activity of glutathione peroxidase (p>0.05). Also, the activities of lipase and alpha-amylase enzymes were decreased (p<0.05), but no significant difference was observed in the alkaline protease activity (p>0.05). In conclusion, the cypermethrin insecticide decreased the growth, survival, and antioxidant and digestive enzymes activities in A. urmiana.

The present study aimed to evaluate the protective effect of vitamins E and C on reducing the effects of dietary oxidized fish oil on the growth, hematological and biochemical indices of rainbow trout fry. For this purpose, 240 fries with an average weight of 12.75±0.25 g were fed with 4 treatments including, treatment 1: a diet containing fresh fish oil, treatment 2: a diet with oxidized fish oil, treatment 3: a diet containing oxidized fish oil along with the low level of vitamin supplements (100 mg/kg vitamin E, 200 mg/kg vitamin C) and treatment 4: a diet with oxidized fish oil along with the high level of vitamin supplement (200 mg/kg vitamin E, 400 mg/kg vitamin C) for 60 days. At the end of the trial, the indices of specific growth rate (SGR), weight gain percentage (WG), and food conversion ratio (FCR) were calculated. Also, the hematological and serum biochemical parameters: cholesterol, triglyceride, high density lipoprotein (HDL), and low density lipoprotein (LDL) were measured. Based on the obtained results, the SGR and WG, were decreased in 2, 3 and 4 treatments and the FCR was increased (p<0.05). The white blood cells (WBC), red blood cells (RBC), hemoglobin (Hb), and hematocrit (Htc) levels were increased in 2, 3, and 4 treatments (p<0.05). The triglyceride and HDL contents were increased in 3 and 4 treatments, respectively (p<0.05). Also, there were not significant differences between different treatments for serum cholesterol and LDL indices (p>0.05). Finally, it was concluded that oxidized fish oil has adverse effects on growth, hematological and biochemical indices, and the vitamin supplements are effective in reducing these effects on the hematological and biochemical parameters.

In this study, the effects of dietary addition of vitamin C, astaxanthin, and lecithin on the fertility ability (percentage of fertilization and eyed-eggs) and activity of SOD, CAT and GPx in the ovarian fluids of Caspian trout (Salmo caspius) were investigated. For this purpose, nine different experimental diets: C0A0L0 (0 mg kg-1 vitamin C, 0 mg kg-1 astaxanthin and 0% soybean lecithin), C300A50L0, C700A100L0, C0A50L6, C300A100L6, C700A0L6, C0A100L9, C300A0L9, and C700A50L9 were formulated and the broodstocks (2.51±0.05 kg) were fed for four months. After sexual maturation and spawning, the ovarian fluids were isolated to measure the activity of antioxidant enzymes (AAE) and to evaluate its fertilization ability. The sperm mixture of 9 male broodstocks was used to measure fertilization ability. The results showed an increase in the relative fecundity and AAE in ovarian fluid. The lowest relative fecundity (680±38 eggs per Kg of broodstock weight) and SOD, CAT, and GPx (816.33±67.60 u/ml, 1.29±0.40 nmol/min/ml and 1.06±0.08 nmol/min/ml, respectively) were observed in C0A0L0 which significantly different from other treatments (p<0.05). The highest percentage of fertilization and eyed-eggs were obtained in C300A100L6 (91.66±5.13% and 87.63±1.3%, respectively) which significantly different from the freshwater treatment (77.66±4.16% and 47.86±5.1%, respectively; p<0.05). According to the results of this research, adding of 300 mg kg-1 vitamin C with 100 mg kg-1 astaxanthin and 6% lecithin can increase the relative fecundity, fertilization ability and AAE in ovarian fluids of Caspian brown trout.

In this study, the effects of different levels of dietary supplementation with vitamin C, astaxanthin and lecithin on some biochemical indices of ovarian fluid (Total protein, ACP, ALP, LDH and AST enzymes) and reproductive performance (fecundity and fertilization rate) of Caspian brown trout (Salmo trutta caspius) were investigated. For this purpose, nine experimental diets were formulated and supplemented with different combinations of vitamin C at levels of 0, 300 and 700 mg kg-1 diet, astaxanthin at levels of 0, 50 and 100 mg kg-1 diet and soybean lecithin at levels of 0, 6 and 9% (C0A0L0, C300A50L0, C700A100L0, C0A50L6, C300A100L6, C700A0L6, C0A100L9, C300A0L9, C700A50L9) and broodstocks (2.51±0.05 kg) were fed for four months. After maturation and stripping, ovarian fluid was separated for biochemical indices and oocytes used for reproductive performance. Based on the results, a significantly increase was observed in the total protein content of ovarian fluid of fish fed with the treatments C300A100L6, C700A50L9, C700A0L6, C0A100L9 and  C300A0L9 compared to the control (p<0.05). Also, the lowest LDH ​​were obtained in treatments C300A100L6, C0A100L9 and C0A50L6, which were significantly different from the control (p<0.05). Treatments C700A0L6 and C0A100L9 had the lowest AST ​​and the highest ALP values, both of which were significantly different from the control (p<0.05). The highest fecundity and fertilization rate were observed in C0A100L9 and C300A100L6 treatments which were significantly different from the control (p<0.05). In conclusion, dietary supplementation of 300 mg kg-1 vitamin C with 100 mg kg-1 astaxanthin and 6% lecithin led to a decrease in AST and LDH enzymes activity and improvement of fecundity and fertilization rates.

In this study, the effects of different levels of dietary supplementation with vitamin C, astaxanthin and lecithin on ionic (K+, Na+, Ca2+ and Mg2+) and biochemical (Total protein, cholesterol and glucose) indices of ovarian fluid, also its effect on sperm motility duration in Caspian brown trout (Salmo trutta caspius) were investigated. For this purpose, nine experimental diets: C0A0L0 (0 mg kg-1 vitamin C, 0 mg kg-1 astaxanthin and 0% soybean lecithin), C300A50L0, C700A100L0, C0A50L6, C300A100L6, C700A0L6, C0A100L9, C300A0L9 and C700A50L9 were formulated and broodstocks (2.51±0.05 kg) were fed for four months. After maturation and stripping, ovarian fluid was separated for ionic and biochemical indices. To evaluate sperm motility, 1 μl of milt was placed under a microscope with fresh water (as a control treatment) or ovarian fluid of experimental fishes. Sperm motility was measured with a chronometer. Results showed that the highest amounts of Na+, K+, Ca2+ and Mg2+ ions were obtained in ovarian fluid of C300A100L6, C300A100L6, C0A100L9 and C300A100L6, respectively, which were significantly different from C700A50L9 (p<0.05). Also, the highest levels of protein, cholesterol and glucose were observed in C700A50L9, C0A50L6 and C0A100L9 treatments, which were significantly different from C0A0L0 treatment (p<0.05). Lowest duration of sperm motility was obtained in fresh water (43.96±2.25 seconds) which was significantly different from other treatments (p<0.05); however, the highest sperm motility was observed in C300A100L6 and C0A100L9 treatments (80.76±2.03 and 80.7±1.76 seconds, respectively).

The present study was aimed to determine the intestinal histopathological changes of common carp fingerling following dietary exposure to Roundup® and the efficacy of dietary inclusion of medicinal plants thyme and rosemary powders to decrease such tissue changes. For this purpose, 300 fingerlings with an average body weight of 15±1.5g were randomly distributed to 5 treatments and fed at 3 different stages as follow: stage 1 with a diet containing 20g/kg of plant powder alone or in combination (treatments 3-5), stage 2 with a diet containing 2.3 mg/kg of Roundup® (treatments 2-5) and stage 3 feeding with diets with neither contaminant nor the medicinal plant powders. Results showed that at the end of the first stage, intestinal tissue had normal microscopic appearance. Pathological changes including necrosis, detachment of intestinal villus, vacuolation in intestinal epithelial cells, infiltration of inflammatory cells along with edema and hyperemia were observed at the end of the second stage in those groups exposed to dietary Roundup® (treatment 2), but those fish previously received diets supplemented with rosemary or thyme (treatments 3 and 4) showed mild tissue changes. Furthermore, simultaneous dietary administration of rosemary and thyme powders (treatment 5) resulted in better tissue protection. Based on the results of the stage 3, after two weeks long recovery period, tissue significant structure amendment was observed in comparison to the previous stage (P<0.05). In conclusion, dietary inclusion of medicinal plant Rosmarinus officinalis and Zataria multiflora powders could reduce the histopathological changes in intestine of common carp fingerling exposed to dietary Roundup®.

In the present study, the effects of different levels of dietary antioxidant supplements on growth performance and biochemical indices in rainbow trout (Oncorhynchus mykiss) fingerlings were investigated. For this aim, nine experimental diets were formulated and supplemented with different combinations of three antioxidants including vitamin E (VE) at levels of 0, 100 and 150 mg kg-1 diet), coenzyme Q10 (CoQ10) at levels of 0, 10 and 20 mg kg-1 diet and selenium forms (mineral, organic and nano-selenium (Nano-Se)) at levels of 0, 0.3 and 0.5 mg kg-1 diet. The fish were randomly divided into these diets with stocking density of 25 per replicate and fed for 56 days. Based on the results, a relative increase was observed in the growth indices of fish fed with the treatment containing 0.5 mg Nano-Se + 100 mg VE. The highest of glucose content was obtained in supplemented treatment with 0.5 mg Nano-Se + 100 mg VE. For cholesterol and triglyceride, the highest values were reported in fish fed with treatments containing 0.5 mg mineral Se + 150 mg VE + 20 mg CoQ10 and 0.5 mg Nano-Se + 100 mg VE, respectively. Similarly, the highest values ​​of HDL and VLDL indices were observed fish fed with 0.5 mg Nano-Se + 100 mg VE. In contrast, the control treatment showed the highest LDL value. The results of this study revealed that supplemented diet with Nano-Se at level of 0.5 mg and VE at level of 100 mg can be effective in improving the growth and blood biochemical indices of rainbow trout.

The aim of this study was to evaluate the histological effects of aflatoxin B1 (AFB1) and zearalenone (ZEA) on the liver tissue of the rainbow trout. In this study, 540 rainbow trout 12.07±0.23 g (Mean±SD), as 9 experimental treatments with three replications were fed separately and simultaneously with diets containing different concentrations of AFB1 and ZEA over 60 days. In this regard, the concentrations of 50 and 100 ppb AFB1 and 300 and 600 ppb of ZEA were used. At the end of the experimental period, the liver tissue was sampled and pathological changes were qualitatively and semi-quantitatively examined. The toxin-induced histological damage included necrosis and deformation of hepatocytes. The severity of tissue lesions increased with increasing dietary levels of AFB1 and ZEA separately and simultaneously. The results showed that the severity of lesions was higher in fish receiving diets containing combinations of AFB1 and ZEA in comparison to other treatments.

Introduction &

In recent years, the use of medicinal plants has been considered to improve growth and immune system indices of fish. Therefore, the present study was carried out to investigate the single and combined effects of Chicory and St John's-wort hydro-alcoholic extracts on growth indices and digestive enzymes activity of rainbow trout (Oncorhynchus mykiss).

For this purpose, 720 fish with an average body weight of 100±5 g were randomly allocated to four distinct treatments including a control group, 3% chicory extract, 3% St John's-wort extract and a combined treatment containing 1.5% chicory and 1.5% St John's-wort extract. The experiments lasted for 12 weeks and growth indices (final weight, food conversion rate, specific growth rate, weight gain, condition factor and hepatosomatic index) and digestive enzymes activity (lipase, amylase and protease) were measured.

The highest and lowest weight gain, specific growth rate and hepatosomatic index were observed in 3% extract of chicory and 3% St John's-wort extract, respectively (p>0.05). Also, the lowest food conversion ratio and the highest condition factor belonged to group received diet supplemented with 3% chicory (p>0.05). The highest amylase and protease activity were observed in 3% chicory treatment (p<0.05). In addition, the highest and lowest lipase activity was observed in 3% chicory and combined treatment, respectively, however they did not significantly differ (p>0.05).

dietary inclusion of 3% chicory extract would improve the growth indices and digestive enzymes activity of rainbow trout.

Present study was carried out to assess effects of aflatoxin B1 on different rainbow trout tissues. In the present study, 207 rainbow trout fingerlings with an average body weight of 9.67±0.2 g were reared for eight weeks in three distinctive treatments (control group, 25 and 50 ppb aflatoxin B1). At the end of the trial, various tissues of experimental groups were studied regarding probable histological alterations. Histological alterations due to dietary aflatoxin B1 exposure including hyperplasia and lamellar necrosis in the gill, necrotic and vascular changes in the brain along with inflammatory cell infiltration and necrotic changes in the intestinal and pyloric region were evident. The severity of pathologies was more pronounced in those fish received 50 ppb aflatoxin B1 content in comparison to the group fed 25 ppb toxin contaminated diet.