Journal of Fisheries
Year:2020 | Volume:72 | Issue:4 |Papers Count:10

Microplastics are particles smaller than 5 mm that can enter to the environment through primary or secondary sources. These particles can be vector for various chemical compounds in the environment, such as pesticides and pollutants. The absorption of these particles into the body of organisms, especially aquatic organisms, causes changes in the activity of their enzymes, especially antioxidant enzymes. The aim of our study was to investigate the effect of polystyrene microplastic and chlorpyrifos pesticide alone and in combination on the superoxide dismutase (SOD) activity tissues of rainbow trout (Oncorhynchus mykiss). Fish were exposed to two concentrations of chlorpyrifos (2 μ g / L, 6 μ g / L), polystyrene microplastic (30 μ g / L, 300 μ g / L), and their combination. Then the superoxide dismutase activity was examined in the liver, kidney and muscle tissues of fish. Analysis of the results with significance level of Pvalue <0. 05 showed that in liver and kidney combination of microplastic and pesticide increased SOD activity and consequently microplastic decreased chlorpyrifos toxicity. In muscle enzyme activity increased at combination of 300 μ g/L microplastic and 30 μ gL-1 MPs pesticide and in combination of 30 μ g / L microplastic and 2 μ gL-1CPF pesticide enzyme activity was decreased. In general, it was concluded that microplastics in liver and kidney decrease the bioavailability of chlorpyrifos pesticide and in muscle increases the toxicity and bioavailability of pesticides.

The present study was conducted to investigate the effects of hydroalcoholic extracts of Marjoram and St John's Wort on growth, immune indices and activity of digestive and antioxidative enzymes in rainbow trout. Treatments included the control group, 3% Marjoram, 3% St John's Wort and the combination of both extracts (1. 5%). The condition factor of fish received 3% Marjoram extract was significantly different from other experimental groups. The highest final weight belonged to diet supplemented with 3% Marjoram extract (P<0. 05). SGR showed an 8. 3% increase in 3% Marjoram extract in comparison to the control group and FCR showed a 2. 34% decrease in the same treatment as well. The immune indices (immunoglobulin, complement sub-path activity, and serum lysozyme) and antioxidant enzymes activity (glutathione peroxidase, catalase, and superoxide dismutase) of different treatments were affected by the experimental diets (P <0. 05). The lowest and the highest values belonged to the control group and 3% Marjoram extract, respectively (P <0. 05). There were significant differences in digestive enzymes activity (amylase, lipase, and protease) (P<0. 05) between the 3% Marjoram extract treatment in comparison to the control group regarding. In conclusion, the results showed that dietary supplementation of the hydroalcoholic extract of Marjoram significantly improved the innate immune indices and digestive and antioxidant enzymes activity of rainbow trout under the commercial farming conditions.

In recent years, the exploitation of aquatic reserves in the world has played a major role in the food industry. Therefore, seaside governments have sought to exploit new opportunities to meet the growing international demand for fish and fishery products by investing in modern fishing fleets and processing plants. But many of the fishery reserves have been damaged by overfishing and uncontrollable fishing. Clear signs are threatening the over-exploitation of valuable fishery stocks, changes in ecosystems, heavy economic losses, international disputes over fisheries management and trade, the long-term sustainability of fisheries and its contribution to food. Governments have therefore sought to take greater account of modern environmental and legal approaches to fisheries management, protecting environmental and environmental issues, as well as economic and social considerations. This descriptive and analytical study has concluded that fisheries and the right to exploit aquatic reserves are of particular sensitivity among the various sectors subject to complementary measures by the UN Conference on the Environment and Internal Rights of Iran. The main laws on the right to exploit aquatic life have been enacted by the Law on the Establishment of the Iranian Fisheries Organization and the Implementing Regulations of the Law on the Conservation and Management of Water Resources of the Islamic Republic of Iran. It is the jurisdiction of the Islamic Republic of Iran and the obligations set forth in the Law on the Conservation and Exploitation of the Marine Resources of the Islamic Republic of Iran are in a manner reflective of international regulations.

The present study was conducted to investigate the antioxidant effect of chitosan coating with the extract of Withania coagulans on chemical changes and sensory properties of silver carp fillet. Fish fillets were kept in 6 treatments and 3 replicates for 18 days at 4° C. Treatments included: control, 0. 5% extract, 1% extract, 1% chitosan, 1% chitosan with 0. 5% extract and 1% chitosan with 1% extract. The chemical factors and organoleptic properties of the samples were studied at 0, 3, 6, 9, 12, 15 and 18 days after storage in the refrigerator. During the storage period, all treatments containing chitosan coating and extract had significant differences in chemical factors and organoleptic properties evaluation compared to control treatment (p<0. 05). The highest chemical indices of pH, PV, TBA and TVB-N up to day 18 of silver carp fillet storage in the refrigerator were in the control treatment [7. 21± 0. 01, 6. 70± 0. 04(meq/kg), 1. 37± 0. 02(mg MDA/kg) and 38. 69± 0. 01(mg/100g)] and the lowest in the 1% chitosan coating with 1% Withania coagulans extract [6. 61± 0. 03, 3. 17± 0. 02(meq/kg), 0. 68± 0. 01(mg MDA/kg) and 18. 43± 0. 03(mg/100g)], respectively. The total utility index of the treatment decreased in day 15 below the acceptability (3. 82 ± 0. 75), but the treatment with chitosan coating 1% and extract 1% had the highest total desirability score by the end of the period (4. 77 ± 0. 77). The results of the current study showed that the strong antioxidant effect of 1% chitosan edible coating with 1% whey extract, had a significant effect on the reduction of chemical changes and also increasing the sensory properties, extend the shelf life and delay the deterioration of silver carp the coated fillets.

Some macroinvertebrates have been identified as bio-indicators indices of stream health and are as the most useful and efficacious. The purpose of this study was to investigate the macroinvertebrate communities and their relationship with environmental factors in the Chehel Chai River of Minoodasht, Golestan province. The study of the abundance and distribution of macroinvertebrate in 2017 seasonally at 5 stations in upstream, forest, tourism area، agricultural and urban areas was performed with 3 replications using Surber sampler (0. 09 m2). In this study، in total fauna including 2 phyllum, 2 class, 4 order and 10 families were identified. The most frequent species were Ephemeroptera and Baetidae. The highest species abundance and the lowest species abundance were observed in winter and in spring, respectively. The highest Hilsenhoff index recorded in summer in urban area (7. 19) and the lowest in autumn in upstream area (4. 06). The Results from the mean HFBI index 5. 44 showed Chehel Tea River with organic pollution class of water quality resulting that an increase in organic matter in the downstream stations due to agricultural activities in this area, release of urban wastewater and tourism affairs. Increase of pollution resistant species such as Tubificidae and Chironomidae families, indicated low water quality in this area.

The aim of this study was to evaluate the effect of seasonal variations on some of the hematological and serum biochemical parameters on some 2-3 years' old great sturgeon cultured in brackish water pens for yearlong from autumn 2015 to summer 2016. At different seasons, after anesthetizing the fish with clove extract, blood sampling was done, from a total of 15 great sturgeon specimens were apparently at healthy condition in 3 separately pen's. Blood samples was analyzed by the routine method used in fish hematology. There were no significant differences in amount of the cortisol, mean corpuscular volume (MCV) and activity of Alanine aminotransferase (ALT) in the different seasons (p>0. 05). The maximum WBCs, Activity of aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were observed in summer (p<0. 05). The maximum RBCs, hematocrit concentration, total serum protein were observed in spring (p<0. 05). The maximum hemoglobin concentration, the mean corpuscular hemoglobin (MCH) and the mean corpuscular hemoglobin concentration (MCHC) were observed in autumn (p<0. 05). The maximum level of glucose was observed in winter (p<0. 05). In conclusion, the result of this study showed that the changes of temperature as a result of season transition may have an important role in the blood parameters of H. huso, resulting that, at the same ecological conditions, any changes in environment temperature, in the water, affecting the blood cells indices in Beluga.

The present study aimed to investigate the effect of Rosa canina L. hydroalcolic extract on growth and nutrition factors and immune indices of rainbow trout (Oncorhynchus mykiss). In this study, 230 fish with weight average of 15± 0. 7 were randomly assigned in four groups and were studies for 42 days with three replications. The experimental treatments including R. canina L-free diet as the control treatment and treatments including 2. 5, 5, and 10 (g/kg) R. canina were the experimental treatments. Fish were fed by 2% of their body weight twice a day and after two weeks, they were weighted and different growth and immune factors were examined. According to the findings of the growth indicators, the treatment containing 5)g/kg( R. canina significantly showed better )FCR(, )SRG(, )CF(, )BWG( and )DGR( indicators (P˂ 0. 05). The results of measuring hematological indicators of )Hb(, )RBC(, )MCV(, )MCH(, and )MCHC( showed no significant difference between the treatments (p˃ 0. 05). WBC showed a significant difference between treatments containing extract (P˂ 0. 05) and the treatment 10) g/kg(showed no difference with the control treatment (P˃ 0. 05). The number of lymphocytes in the treatment group10(g/kg) showed a significant difference with other treatments and the control treatment. No significant difference was observed between the treatments in terms of neutrophils and monocytes. The findings of this study show that the use of 5)g/kg( extract leads to increased growth indicators and 10 )g/kg(leads to increased growth indicators.

This study was aimed to determine the proximate composition and amino acid profiles of the four species of fish, including the Asian sea bass (Lates calcarifer), Rainbow trout (Oncorynchus mykiss), Common carp (Cyprinus carpio) and Nile Tilapia (Oreochromis niloticus). The results showed that amount of moisture and crude protein in Asian sea bass were significantly higher compare to other species (p<0. 05). But, the amount of crude fat and ash in common carp were significantly higher than other species (p <0. 05). The amount of essential and non-essential amino acids showed a significant difference (p<0. 05). Based on the results, Σ EAA and Σ NEAA in the O. mykiss were significantly higher than the three other species (p <0. 05). The proportion of Σ EAA to Σ NEAA showed a significant difference among four species (p<0. 05). The highest ratio of Σ EAA to Σ NEAA was observed in Nile Tilapia and the lowest ratio Σ EAA/ Σ NEAA recorded in Common carp. In conclusion, it seems that Asian sea bass and Rainbow trout due to higher nutritional values compare to common carp and Nile Tilapia are selected by consumers.

In this experiment, the effect of different levels of malic acid (0. 0, 2. 5, 5, 7. 5 and 10 g/kg diet) was evaluated on hematological, biochemical and immunological indices of juvenile Siberian sturgeon (Acipenser baerii). For this purpose, a total number of 375 fish (33. 72 ± 0. 60 g initial weight; mean ± S. E. ) were randomly assigned to 15 circular concrete tanks (1. 85 m diameter and 0. 25 m depth). The fish were distributed in 5 treatments with 3 replicates and were fed during 8 weeks. The results of hematological showed that there was no significant difference among treatments in the number of red blood cells, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration(P>0. 05). There was a significant difference in glucose, total protein and globulin levels among treatments (P<0. 05). The lowest level of glucose, total protein and globulin were observed in treatment of 7. 5 g/kg. There was no significant difference among treatments in other parameters including albumin, cholesterol, triglyceride, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase (P>0. 05). The results of immune indices showed that there was no significant difference in white blood cell count and IgM (P>0. 05). The highest amount of total immunoglobulin and lysozyme activity were observed in treatment of 2. 5 g/kg which had a significant difference with control treatment (P<0. 05). Based on the results obtained, it was concluded that the malic acid used in this study had a minor effect on improving some blood and immune indices of juvenile Siberian sturgeon.