مجله علمی شیلات ایران
سال بیست و هفتم شماره 5 (پیاپی 109، آذر و دی 1397)

This study was conducted to evaluate the effects of alfalfa (Medicago sativa) extract on growth performance, feed intake, body composition and some of the serum parameters of Rainbow trout (Oncorhynchus mykiss). In this study, a total of 240 rainbow trout were weighted average 8/36±0.2(g) and randomly distributed in four treatments (control), 0.5, 1, 1.5% of extract per (kg) of diet with three replications in plastic tanks. Fish were placed and fed with extract containing food for 60 days. During this time, physicochemical factors of water were measured. At the end of the period, growth index and serum parameters calculated. The results showed that growth performance in treatments that fed with 1% alfalfa extract had a significant difference compared to control treatment (p<0/05). In the indexes of body compositions, an increase in the amount of fat was observed in 1% treatment of the extract, while there was a significant difference with the control group (p<0/05). Serum parameters showed that there were significant differences between fish fed with alcoholic extract of alfalfa and control group (p<0/05). The lowest cholesterol and triglyceride levels and the highest level of protein were observed in the 1.5% extract group. Also, the highest amount of glucose was observed in control treatment. The results of this study showed that the addition of alcoholic extract of alfalfa (1 -1.5 %) to fish diet can improve the growth performance and blood biochemical parameters of rainbow trout.

Mariculture of trout fish in cage, which is a new approach of Iranian fisheries organization was followed by the last decade draining years and estimation limitation of fresh water fish production in Iran, harvested more than 2700 MT. of trout fish which is the successful choice of cage cultured fish species in three northern provinces - Caspian Sea. Final costs of fish production affected by different financial parameters such as fixed and current investments, in cage condition determined using industrial cost accounting or final production cost. In order to obtain final costs of each kg trout fish cultured in cages of Mazandaran coastal water, questionnaire from 5 trout fish cages were gathered during 2016 in that province. All data and costs are based on a cage with 15 MT capacities. Overall, initial fish biomass for releasing to the cage with the highest costs(41%) of total costs, followed by feed 37%, maintenance and 5 years amortization fixed investment (10%), Insurance(5%) and labor costs(0.018%) are the main factors final costs of the cage fish production. In this study this final production cost of one Kg fish cultured in cages system of Mazandaran province was calculated 129764 , which is 10 % lower than the price of fish cultured in raceway system(142740 Rials).

Caspian Sea sturgeons, are the most valuable species due to the production of meat and caviar. Sturgeon cultures as like other fish rearing, the outbreak of all kinds of infectious diseases in the farms can be expected and in this regard, isolation, identification and consumption of the local probiotics can be very important in the health promotion and growth indices. For this purpose, sampling has been done from 38 fish, in addition to culturing and counting aerobic and facultative anaerobic bacteria (AFAB) on Triptic Soy Agar, and lactic acid bacteria (LAB) were also isolated and counted on MRS Agar. In Siberian sturgeon, the average number of LAB were 2.72±0.11 (Log CFU g-1) and the average of AFAB were 6.79±0.19 (Log CFU g-1). Through 16SrRNA gene sequencing, LAB including Weissella confusa, Lactococcus lactis, and L. garvieae were molecular identified in the Siberian sturgeon intestines. Complete laboratory and field studies for use of these bacteria as probiotics is required.

Fish is one of the domestic products that is unmatched in terms of protein and unsaturated fat, and its importance as a healthy food is known to all. Keeping in mind, resource scarcity, economic method of increasing this product is the optimum use of the factors of production. The aim of this research was to estimate production function and calculation of productivity of warm water fish production factors in Kermanshah province. The statistical population in this reaserch were all of active, fish farms which were studied in full details. A part of required data of this research was collected from official statistic books of government and another part from interview with farmers and experts of fishery department of Kermanshah through distribution of 46 questionnaires. The production function has been estimated with help of Eviews and with OLS approach and through priority model of Cobb-Douglas was finally selected. Result showed that area under cultivation (land), concentrate and maize, fodder, lime stone, labour, experience of manager of the farm, use of air purifier machine and geographical condition of the region had significant effect on production (p<0.05). Total coefficient of independent variable in estimated production function was approximately 1.1 which was an indication of increasing return to scale. Elasticity of production of area under cultivation was more than other inputs which indicated that the area under cultivation must expand and more area go under cultivation of this product. In addition coefficient of labour was estimated 0.31 which indicated more employment of labour force must be done in order to approach towards optimum product. According to obtained results of this research, education did not have a significant effect on production, while experience had a positive and significant effect on it and this showed that the level of technology in this industry was not so high. The finding also showed that geographical region and use of air purifier had a significant effect on the production of warm water fish. Therefore on this base the farms under review were divided into three categories and the average productivity, marginal productivity and total factors productivity were calculated for each one of these categories. Just in small number of farms, related to one of the categories the measure of VMPxi / Pxi for descriptive variable was equal to 1 and for other two categories this measure was not equal to one. Which means that the inputs were underemployed? Therefor it seems in order to improve efficiency in input consumption, the fish farm owner can attain maximum profit by using substitution principle.

In this research, Macrobrachium nipponense small and non-native shrimp of the Anzali Lagoon, after catching and washing, were immersed in 10% salt solution at a ratio of 1 to 2 at 80 °C for 3 minutes. Then, drained samples were dried at 70 °C for 7 hours in a vacuum oven dryer. 4% of dry meats were used to enrich the soup powder with a new formulation. Prepared soup powders were packed in a vacuum metallic polyethylene films and stored for 6 months at room temperature. The nutritional value of shrimp-rich soup powder showed that this product contains protein (10%) and high unsaturated fatty acids. During the storage period, based on chemical experiments, the moisture content of soup powder (8.55-9%) was less than 10% and in terms of fat oxidation, proxide values (0.11-2.54 meq oxygen/1000g oil) and thiobarbituric acid (0.34-0.76 mg malonaldehyde/1000 g sample), samples were under favorable conditions up to six months. In The microbial evaluation, the fourth month was the end of the shelf-life of shrimp-rich soup powder; because in this month the total number of bacteria in the soup was counted for 4 CFU/ g of sample and the number of mold and yeast increased to 3 CFU/g of sample. Also, the results of sensory evaluation showed that the overall acceptance of soup powder decreased from 4 to 2.5 scores with increasing time. This score reduction in soup powder was consistent with the results of microbial evaluation in this study. As a general result, soup powder enriched with 4% M. nipponense dried shrimp meats under vacuum, due to its unique flavor, can be produced and used as a functional food in the industry by people all over the country.

In this research, concentration of eleven elements (As, Fe, Hg, Zn, Pb, Se, Cd, Cr, Cu, Mn, Ni) in the muscle tissue of 40 Oriental river prawn (Macrobrachium nipponense) collected by bait trap from the Siah Darvishan River, Guilan province, Iran were determined using Varian Atomic absorption spectroscopy. The lowest and highest mean concentrations of metals were observed, as follows: Zinc 39.6-46.7, Copper 24.2-28.3, Iron 15.27-18.19, Manganese 3.36-3.82, Selenium 0.78-0.84, Arsenic 0.61-0.74, Lead 0.34-0.41, Nickel 0.34-0.41, Chromium 0.16-0.20, Cadmium 0.12-0.15 and Mercury 0.069-0.078 (μg g–1d.w.), respectively. According to the results of this study, mean concentrations of all elements in the muscle tissue of Oriental river prawn, except for Arsenic and Manganese were less than threshold limit value recommended by FAO/WHO international standard.

Vibrio harveyi is one of the opportunistic marine environment bacteria that are considered as one of the main causes of Asian seabass vibriosis diseases in many marine cage farms in the world. The aims of this study were isolation and identification of these bacteria in cultured Asian seabass in farms, located southern provinces of IRAN (Khuzestan, Bushehr and Hormozgan). In this study, a total number of 110 Asian seabass (80, with clinical sings of disease and 30, apparently healthy fish) with different body weight ranging 50-700g were sampled. Isolation was done from internal organs (kidney, heart, spleen and liver) in common method of bacterial isolation and isolates subjected to phenotypic and molecular characteristics using duplex PCR amplification of the 16SrDNA & vhh genes respectively genus & species-specific gene. The results of PCR showed that of the 95 phenotypically identified isolates, only 65 isolates belong to the genus vibrio and 46 (70.76%) of them were identified as Vibrio harveyi. These results indicate a high present of Vibrio harveyi in cultured Asian seabass in studied farms. Results of the biochemical characteristics of the isolates confirmed with PCR, showed isolates have different reaction in several biochemical tests. Accordingly, the duplex PCR method presented in this study was introduce as an accurate and rapid method for diagnosis of V. harveyi.

Dunaliella sp. is from division of chlorophyte algae that has a global distribution and is abundantly reported in the coastal waters of Chabahar Bay. This algae is a euryhalin species which may support high temperatures and lack of Nitrogen conditions in the sea. Also as a response to environmental stresses it fluctuates pigment reserves specially the Beta-Carotene. The aim of this study was effects of salinity on growth, chlorophyll and β-carotene concentration in Dunaliella sp. In this study in beyond the separation and purification of Dunaliella sp. from seawater, the impact of different levels of salinity (0.5, 0.75, 1, 1.5, 2, 3 and 4 mol NaCl) on growth, the amount of chlorophyll and β- carotene were measured during a period of 4 weeks. Chlorophyll a, b and β-carotene contents were determined spectrophotometrically from algal pellets using 80% (v/v) acetone/water mixture. Results showed that the Dunaliella sp. in treatments of 0.5, 0.75, 1, 1.5, 2, 3 and 4 mol NaCl could grow, but the maximum growth of this algae and the maximum amount of β-carotene were observed in salinities between 1.5 to 2 mol NaCl (p<0.05). Parallel to growth of the algae the production of chlorophyll a and b was increased in all salinities treatments but their production causes a decrease in β- carotene production.

Water quality parameters of Kaj and Sendegan rivers in Chaharmahal and Bakhtiari province were assessed for rainbow trout culture. For Kaj and Sendegan rivers, 6 and 5 sampling stations were selected, respectively. The water samples were collected once a month from May to October (2015) and were sent to laboratory for assessing: Nitrite, Ammonium, Soluble Phosphate, BOD5, COD, TSS, TDS, Cu, Zn, Hg, Cl-, organophosphate toxins, pH, Malachite green and EC. The Nitrite concentration in Sendegan River (0.106 mg/l) was equal to standard (p>0.05) and in Kaj River (0.079 mg/l) was lower than standard (p<0.009). The soluble Phosphate concentration was higher than standard (p<0.0007) in the studied rivers (0.162 and 0.152 mg/l for Kaj and Sendegan, respectively). Measured TDS for Kaj (225 mg/l) and Sendegan (335 mg/l) rivers were higher than standard (p<0.03 and P<0.0001, respectively). BOD5 and COD concentrations were lower (p<0.0001) than its standards for two rivers (2.67 and 5.56 mg/l for Kaj River and 2.16 and 4.22 mg/l for Sendegan River, respectively). Amount of Malachite green in the last station of Kaj River was 0.003 mg/l (p>0.05) and in the last station of Sendegan River was 0.065 mg/l (p<0.05). The EC of Sendegan River (562 µs/cm) was higher than standard (p<0.0003). Other parameters in the both rivers, were lower than the standard (p<0.0001). Generally, water quality of Kaj and Sendegan rivers were not suitable for rainbow trout culture.

This study was performed to survey the relationship between water physicochemical factors and determination the effective parameters on Litopenaeus vannaemi survival in three ponds of three different farms with same stocking (250000 pl) and same storage time during 109 days (Days of culture), from June to September, in shrimp culture ponds of Abadan-Choebdeh. The results showed that the highest correlation between salinity and temperature, as well as salinity and pH is established. Nitrate and phosphate values ​​recorded during the culture period were outside of the standard range. The results of correlation between chemical feature and survival showed in all of three farms, the nitrate and ammonia had the maximum effect on shrimp survival which this relationship was expressed inverse. According to the results, the mean of primary weight, final weight and weight gain was observed in T3 more than T1 and T2 , and survival rate in T3 and T2 was more than T1 at the end of the culture period. It seems that the level of protein in diets play an important role in the nitrate and ammonia scale and finally in survival.

The present study conducted to evaluate the effects of soybean lecithin on growth indices, body composition, digestive enzymes activities and intestinal histomorphometry of Caspian salmon. Ninety fish (350g ± 10) were randomly divided into three treatments with three respective replicates. The first treatment (control group) was fed with commercial feed, while the second group received diet supplemented with 12% soybean oil, and the third one received feed supplemented with 6% soybean oil and 6% soybean lecithin for 90 days. Weight gain was indicative of the statistical superiority of treatment 3 over control group and treatment 2. In addition, FCR of treatment 3 was only significantly different from control group (p≤0.05). There were significant differences regarding moisture content of treatments 2 and 3 in compare to control group (p≤0.05), however, protein and lipid contents of treatments were not significantly different (p≤0.05). Furthermore, energy contents of treatments 2 and 3 were significantly different (p≤0.05). Digestive enzymes activities (protease, lipase and amylase) of treatment 3 significantly differed from treatment 2 and control group (p≤0.05). Morphometric characteristics of intestine including epithelium thickness and external muscle thickness of treatments 2 and 3 were significantly different from those of control group (p≥0.05). In conclusion, supplementing Caspian salmon diet with 6% soybean lecithin improved growth and some physiological parameters of the fish.

Probiotics are widely used in modern aquaculture. The aims of this study were to investigate the effect of probiotic bacteria of Bacillus subtilis strain on growth parameters of rainbow trout and to determine the best application rate of this bacterium. The results of this research will be widely used in improving the production of this valuable species and creating new perspectives in breeding conditions and increasing its nutritional value. In this study, the effect of Bacillus subtilis IS02 in a completely randomized design with four different treatments including: T1 probiotic supplementation- free, T2 containing 106, T3 with 107 and T4 with 108 CFU/g of B. subtilis in diet for 30 days on some growth parameters (WG, SGR, FCR, PER, LER, PPV, LPV, CF, VFI, FE, DGI) was investigated. Data analysis was performed using one-way ANOVA and Bonferroni test. The results showed that T4 treatment with a concentration of 107 CFU/g had a significant effect (p=0.001) on the increase of protein value (PPV), but no significant effect was observed in other parameters of growth (p> 0.05).

The current study has determined the toxicity effects of copper nanoparticles (CuNPs) on the some vital organs such as gill, liver and kidney of Caspian Roach; Rutillus rutillus caspicus. For this purpose, 120 fishes were used as experimental fishes and exposed to 0.1, 0.2 and 0.5 mg/L of Cu nanoparticles for 21 days, and 30 fishes as control. The mean water temperature of the aquaria was 22±2 ºC, dissolved oxygen 5.2 mg/L, pH at 7±0.004 and the concentration of Calcium Carbonate was 270 ppm. On the 7, 14 and 21 days after exposing the fishes to CuNPs, three fish were randomly selected from each aquaria, sacrificed and samples from their liver and blood were taken. Changing in antioxidant enzymes level were determined by evaluation of superoxide dismutase (SOD) and catalase (CAT) activities in the blood of fish. In first week, the samples that exposed to 0/1 mg/L of CuNPs concentration had more activities in SOD and CAT levels (p<0.01) but other treatments (0.2 & 0.5 mg/L) didn’t have any increase in enzyme activities. The liver microscopic sections were prepared and stained by H&E method and examined by light microscope which showed histological alternations in the liver tissues. Histological changes in liver included blood congestion in the central veins, cytoplasmic vacuolation of the hepatocytes, cellular hypertrophy, congestion in the blood sinusoids and necrosis of the hepatocytes and nuclear pyknosis. The degree of damages was more intensive at higher CuNPs concentrations. Evaluation of these changes could be useful in estimating the harmful effects of CuNPs. The result of the study showed that CuNPs could cause decrease in antioxidant enzyme activities and severe damages in the liver tissues of Caspian roach; Rutillus rutillus caspicus and have lethal effects for fish.

This study was conducted to evaluate the effect of replacing dietary fishmeal with canola meal on growth performance, digestion, indicas hematological and thyroid hormones level of Siberian sturgeon (Acipenser baerii). Five isonitrogenous (45%crude protein) and isocaloric (18.53KJg-1) were formulated by replacing 0(control), 10 (CM10), 20(CM20), 30(CM30) and 40%(CM40) of fishmeal with canola meal. Fish juveniles with initial weight of 22.80±0.34 g (mean ± SD) in 5 treatments and 3 replications were fed for 10 weeks. At the end of the experiment, growth performance, digestion, hematological parameters and T3 and T4 hormone levels were measured. The results of this study showed that there were significant differences in growth indices, body composition and T4 level of fish fed different diets (p<0.05). There were no significant differences in growth performance between control, CM10, CM20 and CM30, but the lowest growth performance were observed in CM40 and there was significant differences in growth performance between CM40 with other treatments. There were no significant difference in growth performance between CM30 and CM40. There were no significant differences in hematological indices between fish fed differences diets. There were no significant differences in T3 level between of fish fed differences diets, but significant differences were observed in T4 level in fish fed different diets. The lowest level of T4 was observed in CM40 and there were significant differences with control, CM10 and CM30. There were no significant differences in T4 level between CM20 with CM30 and CM40,but were significant differences between CM20 with control and CM10. There were no significant differences in T3:T4 ratio between fish fed different diets. The results of the present study showed that 30%fish meal can be replaced by canola meal without negative effect on growth performance, body composition, hematological parameters and thyroid hormone levels of Siberian sturgeon.

The aim of this study was to measureing the amount of essential metals, copper, zinc and iron in muscle of Lethrinus nebulosus in Bushehr seaport in summer 2017. 20 samples of L. nebulosus were randomly caught. After biometry of the samples, the muscle tissues of the samples were separated and chemical digestion of the samples carried out based on MOOPAM procedure, then level of heavy metals were measured by graphite furnace atomic absorption instrument. Based on the obtained results the mean and deviation concentrations of heavy metals of copper, zinc and iron in muscle tissue of L. nebulosus were calculated 5.678±0/726, 17.096±1.452 and 1.498±0.406 mg/kg dry weight respectively. The results revealed that the copper and zinc metals concentration in muscle tissue of L. nebulosus in study station are lower than the levels permitted within the standards of World Health Organization (WHO), Food and Agriculture Organization (FAO), National Health and Medical Research Council (NHMRC) and Ministry of Agriculture, Forestry and Fisheries (MAFF), but the iron level or concentration higher than the standard level of Food and Drug Administration (FDA).

The aims of this study were to determine the permissible consumption limits and risk assessment of three fishes species Platycephalus indicus, talamparoides Carangoides,and Liza abu in Shif Island, Bushehr province. In this study, 30 fishes of 3 species (Platycephalus indicus, talamparoides Carangoides, Liza abu) were collected from Shif Island coastal waters using a fishing boat. According to the results, the permissible consumption limits (CRlim) of Platycephalus indicus for Ni, Mn, Zn, Cu and Fe were 0.21, 5, 0.57, 0.23 and 2 kg/day respectively, for talamparoides Carangoides were 0.29, 3, 0.66, 0.37 and 1 kg/day respectively and for Liza abu were 0.20, 2, 0.56, 0.76 and 1 kg/day respectively. The maximum daily and weekly intakes were obtained for Fe in Liza abu, and the minimum was found for Manganese in Platycephalus indicus. In this research, the metal values were lower than the world standard, except for Mn in Liza abu and Ni in three fishes species that the high concentrations of Ni in fish species may cause problems for the inhabitants of the island in long time. The food risk assessment of fishes species indicated that the consumption of these fishes with current levels (20 gr/day) in stand of Fe, Cu, Zn, Mn and Ni do not possess a risk to consumers. But due to the permissible limit values, excessive consumption of these species may cause problems for the consumer.