مجله علمی شیلات ایران
سال بیست و هشتم شماره 1 (پیاپی 111، فروردین و اردیبهشت 1398)

One of the most important bacterial diseases in aquaculture is Streptococosis/loctococosis. Meanwhile this disease has been known as a zoonosis disease, and then fish vaccination against this disease is important. In this study the specific immunological responses of rainbow trout (Oncorhynchus mykiss) to vaccination with bivalent lactococcal/streptococcal vaccine were investigated. Two hundred and fourty rainbow trout fingerlings (30±1.7g) were randomly divided into two equal groups in triplicates. Fish in vaccinated treatment intraperitonealy injected with 100 microliter vaccine on the first day and booster vaccine were directed by immersion route on day 30th of study. The control group was injected with sterile PBS, identical to vaccinated group. Blood samples were collected from vaccinated and non-vaccinated groups at days 0, 14. 30, 45 and 60 of study and antibody titer were subsequently performed. Sixty days after initial immunization all groups were challenged by lethal dose of Streptococcus iniae and Lactococcus garviae, mortality rate was calculated and compared between the groups. Survival rates of vaccinated fish after challenge with S. iniae and L. garviae were 62±7.22% and 68±.8.67% respectively. The results demonstrated that specific plasma IgM antibody titer induced by commercial vaccine were significantly higher compared to the level in the control group (p<0.05). Our results demonstrated that not only these bivalent vaccines can effectively protect rainbow trout against L. garvieae and S. iniae, but also can increase antibody titer in rainbow trout, then it could offer an appropriate strategy to prevent these infections in rainbow trout farms in Iran.

In this study, freshly harvested prawn, Macrobrachium nipponense were hydrolyzed with pepsin to develop a food ingredient and iron supplement. The degree of hydrolysis, protein/peptide concentration and iron-chelating capacity were verified by TCA soluble assay, direct UV spectrophotometric method and orthophenanthroline-based colorimetric assay, respectively. The result of TCA soluble assay revealed a high rate of hydrolysis for the first 6 h, reached the steady-state phase after 8 hours. The highest iron-binding capacity of the hydrolysate (49.7 μg/mg of peptide/protein) was obtained at a degree of hydrolysis of 36.5%. The partial lysate generated by pepsin had high levels of glycine, proline, arginine, alanine, and valine. It seems that in peptic M. nipponense hydrolysate, peptide bonds of Gly, Pro, and Ala residues as well as amino or imino group from Arg side chain support additional affinity for iron. Consequently, hydrolysis and enrichment would be a proper strategy for appropriate gain from this abundant prawn, into a high functional product.

One of the problems associated with surimi, which is made from fresh water fish, is its low whiteness value compared to the marine fish species, mainly due to the redness of its muscles. In this study, hydrogen peroxide at concentrations of 1, 2 and 3% along with other variables such as water to mince ratios of 1:2, 1:3 during 1, 2 and 3 washing cycles was applied in order to improve the color quality of surimi obtained from Silver carp mince. According to the color test and the amount of utilized water for washing, in the one and two washing cycles, except for treatment 4 (1% H2O2 concentration, mince: water ratio of 1: 2, 1 washing) and treatments 10 (1% H2O2, mince: water ratio of 1: 2, twice washing) which resulted lower whiteness, the other treatments can be considered as an effective treatment to improve the color of surimi. According to the results, treatments 4 and treatment 10 with a numerical value of whiteness index 68.20 and 68.37, respectively, were significantly different compared to other treatments within their groups (P<0.05). In terms of 3 washing cycles process, no significant difference was observed among the numerical values of the white index of the treatments (P>0.05) as it was recorded from 62.56 to 65.25. Finally, it was found that increasing the concentration of hydrogen peroxide along with the washing cycles could significantly improve the color of waste water obtained from different washing cycles as well as the whiteness of the resulting surimi.

Hematological parameters are useful indicators for assessing the physiological conditions of Sturgeon in response to stress, pollutants and physiological and ecological changes. The aim of this study was to investigate the effects of nitrosomonase and nitrobacter in removing ammonia and on blood and serum indices of Huso huso .Four treatments were designed with densities of bacteria (0, 101, 103, 105) in 100 ml with three replications were performed using 120 sturgeon fish with an average weight of 200 ± 800 g and a length of 55±2 cm in 12 fiberglass tanks (4000 liters per each 10 fish) for 12 weeks and two weeks of initial compatibility. Based on the results, the highest amount of ammonia was observed in treatment 1 (control) with significant difference (p≤0.05) with treatment 3 and no significant difference with other treatments. Ammonia levels were not significantly different (p≥0.05) between the hours measured in each treatment. Among the blood parameters, only neutrophil was significantly different in treatments (p≤0.05). Serum blood parameters such as aspartate aminotransferase (AST), alkaline transferase (ALP), keratin phosphatase (CP), total protein and alanine aminotransferase (ALT) were not significantly different (p≥0.05). Lactic dehydrogenase (LDH) had a significant difference with other treatments (p<0.05). Nitrosommunos and nitrobacter had a positive effect to remove ammonia from the water of the culture environment and had no negative effect on the physiological conditions of sturgeon (huso huso) blood parameters.

Chemical-ecological studies of sponges show that the secondary metabolites are only defense system. Nowadays natural products with biological activities are used as drugs for treatment of human diseases. One of the most important biological activities of sponges is cytotoxic activity. This study investigated the cytotoxic activities of α-Santonin compound which extracted from Dysidea avara. In this study, dried powder of sea sponge was extracted by acetone solvent. Then, in order to isolate the α-Santonin compound, the extract was washed by silica gel column chromatography with N-hexane and ethyl acetate solvents. The IC50 value of this compound was measured by XTT assay on cancer cell lines, Jurkat/E6-1, KB/C152 and healthy Hek293 cells. The α-Santonin compound with the chemical formula C15H18O3, which belongs to the Sesquiterpene-lactone group, was identified by gas chromatography, with a purity of 91% in fraction No. 24. The IC50 value of the α-Santonin extracted from sea sponge compared to the oral epithelial cancer cell line and lymphocyte cell line was 88.90 μg/ml and 38.09 μg/ml respectively. Our study demonstrated that α-Santonin extracted from D. avara has an extremely potent cytotoxic effect that could be used as an anticancer agent.

By reducing the water level in the Gorgan Bay, as a result of the decreasing in the Caspian Sea water surface, the optimum distance will change between fish farms. The purpose of this study was to investigate the optimal distance variation due to water level reduction, Hydrodynamic and Transport modules of the Mike 21 model was implemented under 15 scenarios by considering western prevailing wind and in 5 levels. Wave radiation tension was implemented using the Near Shore Wave module in 15 scenarios and used as input in hydrodynamic models. Dispersion coefficient was extracted by salinity modeling in the year 2012 and at a level of 26.5 m and used it in other models. The modeling results in most scenarios indicate that the pollutant displacement is in the direction of the dominant wind from west to east in the southwest farm and was from east to west in the northeastern farm opposite to the dominant wind. Mostly, wind speed increasing and water levels decreasing will increase the optimum distance and will reduce time to dilute pollutants. The maximum mean optimum distance in the northeast and southwest farms were 487 and 2615 meters in level of 28 meters, respectively. The minimum mean optimum distance in the northeast and southwest farms were 194 and 999 m in level of 26.5 and 26 meters, respectively. In order to reduce the ecological and economic disasters caused by the effects of the Caspian Sea level reduction on the optimal distance between farms in future, it is recommended to restructure fish farms in the Gorgan Bay.

One of the problems products produced of imported frozen fillets tilapia fish such as nuggets, bitterness of the products in during storage in freezing conditions. Since in this study, the quality of imported frozen fillets with fillets of tilapia that cultured in Iran, during two months was evaluated and the trend of corruption in the fillets was compared. According to the results of evaluation (proximate composition, thiobarbituric acid (TBARS), free fatty acids (FFA), Hypoxantin (HX), formaldehyde (FA), dimethyl amine (DMA), peptides soluble in trichloroacetic acid (TCA), protein solubility, electrophoresis and fatty acid profile) the DMA and TCA levels of imported fillets were 0.6 miligram DMA-N Per 100 g sample and 0.35 milimol tyrosine per g sample respectively, that were higher as compared to DMA and TCA cultured fillet zero time (0.2 miligram DMA-N Per 100 g sample and 0.18 milimol tyrosine per g sample respectively) and their protein contents was lower than cultured fillets (15.65 % in imported fillet and 18.60 % in cultured fillet). As a result, high levels of peptides and their production during subsequent processes in imported frozen fillets can be a source of bitterness for the products produced from them.

Parasite communities of pike (Esox lucius L. 1758) were calculated  in  Anzali Wetland along with evaluating  their impacts on biometric characticties of the fish host. A total of 4338 parasites from 11 diferent species were identified including: Ichthyophthirius mutifiliis (21.88%); Trichodina sp. (8.59%); Henneguya sp. (0.78%); Tetraonchus monenteron (60.94%); Diplostomum spathaceum (23.44%); Rhipidocotyle illense (9.37%);  Posthodiplostomum cuticola (0.78%);  Raphidascaris acus (41.41%); Rhabdochona helichi (8.59%); Eustrongylides excisus (2.34%) and Lernea cyprinacea (3.13%). The occurrence of  P.cuticola in E. lucius is  reported for the first time from Anzali Wetland. By increasing total length, the average weight of the infected fish raised from 26.54 ± 12.94 g to 472.39 ± 68.38 g, the condition factor (K) from 0.64 ± 0.11 to 0.66 ± 0.06 and the gonadosomatic index (GSR) from 0.15±0.55 to 0.75±1.88. In healthy fish, the instantaneous growth rate (G) in the age groups of 1+ to 0+ years old was higher (0.617) than in the other groups, while in infected fish, the instantaneous growth factor had fluctuations in different age groups. On the other hand, the age groups of 3+ to 2+ years old had the highest growth rate (0.773). There were significant differences between the prevalence of parasites and some biometric characticties in infected fish (p<0.05).

One of the unique and important aquatic species of Anzali wetland, Anadonta cygnea, native Anzali wetland and its rivers, and the most important two-body system of this blue system, has declined sharply in recent years due to various reasons. Is this species is considered to be smuggling and has a special sensitivity to environmental changes (biological pollution assessment).Anzali Wetland is a special ecosystem for the cultivation and development of various types of aquatic animals on the southern of the Caspian Sea. On the other hand, the special position of the mollusks in relation to the use of other creatures from them and the industrial industrial applications and the role of water purification necessitates the study of the Anadonta cygnea diet in the Anzali Wetland. Of the 14 stations surveyed, only 9 stations, including the stations entrance of the West Bank , Bahambar , Shijan , Soussar Rogah , Abkenar , Mahruzha , Karkan , Siakishim, and finally Hindakhale, were caught in the Anodont shell. In the above study, the average length and weight of Anadonta cygnea, regardless of their specific situation, were 8.25 ± 1.17 cm and 58.03 ± 27.53 gr, respectively. The most frequencies and distribution in different seasons belong to the entrance stations of West Wetland, Behmbar, Shijan and Sossar Roogah and the highest average age in the spring seasons belonging to the station of Behambar (7 years old), summer related to Mahrooz station (8 years old) Autumn belonged to the Sossar Roogah (7 year old) sonar station and finally to the Shijan Station (8 years old) winter. In general, it can be said that Anadonta cygnea feed from phytoplankton branches of Chlorophyta and Bacillariophyta more than other branches throughout the year. In an experimental study of the Anzali Wetland anodentic sheath, it can be stated from the different stations that most of the phytoplankton species used from the green algae of Scenedesmus, Chlorella and Pandorina were from the branches of the Diatoma Cyclotella, Cembella and Navicula algae. Nutrition from zooplankton was detected in a small amount, from the Ciliophora of Arcella and Amiibia, from Cilliata, and finally from rotifers Brachionus, Asplachna and Rotaria. Suitable substrate type is sandy with some flowers, with the range of silt-clay changes in stations ranging from 80.8 ± 3.8 to 97.64 ± 2.2 percent. In the study of Anadonta cygnea diet, it was determined that the above Anadonta cygnea are fed by filtration (non-selective selection). Therefore, with regard to different ages and abundance in the living environment, in the first place (more than 90%), branches Microscopic phytoplankton from 5 to 20 micron (branches such as Chlorophyta, Bacillariophyta and Cyanophyta), and in the next step (about 10 percent), microscopic zooplankton from 5 to 30 microns (orders such as Ciliopoda, Rhizopoda, Rotatoria and Cladocera, as well as detritus in these dimensions).

The aim of this study was to investigate the effect of fermented silage on growth performance and apparent digestibility of protein at feed of rainbow trout. In this study, Anchoy Kilka meal were mixed with 25% wheat flour and inoculated with microorganisms (108 cell/ml) and kept in an incubator for 14 days at 37 ºC. Fermentation of Anchoy Kilka has resulted in a significant increase in moisture, protein and pH values at the end of the period. Ash content of the fermented product was almost twice as that of the unfermented fish meal in all of the samples. Fiber and crude fat contents of the fermented product was respectively reduced and increased (p<0.05) in comparison with the initial product. Replacement of fish meal with fermented silage (0, 25, 50, 75 and 100%) showed that there was significant difference in growth performance and apparent digestibility protein (p<0.05). Fish fed with 25 percent fermented silage had the best of growth performance and apparent digestibility of protein (p<0.05). In conclusion, the results of this study suggest that fish meal produced with fermentation manner can be used as good alternative for feedstuff of rainbow trout.

The effect of stocking density and dietary aflatoxin B1 along with including rosemary and thyme powders on digestive enzymes activity of rainbow trout was evaluated. 600 fish with an average weight of 90±3 were randomly allotted into six experimental groups consisted of (1) stocking at 15 kg.m-3- feeding diet devoid of aflatoxin, (2) stocking at 45 kg.m-3-feeding diet devoid of aflatoxin, (3) stocking at 15 kg.m-3-feeding diet containing 50 ppb aflatoxin, (4) stocking at 45 kg.m-3-feeding diet containing 50 ppb aflatoxin, (5) stocking at 15 kg.m-3-feeding diet containing 4% rosemary and thyme powder and 50 ppb aflatoxin and (6) stocking at 45 kg.m-3-feeding diet containing 4% rosemary and thyme powder and 50 ppb aflatoxin. Activity of alkaline protease, lipase and amylase was only affected by fish stocking density to the extent that those fish were reared in higher density showed increased digestive enzymes activity (p<0.05). Interactive effect of two studied factors (stocking density and dietary supplementation of medicinal plants) significantly affected activity of amylase and alkaline protease. However, lipase was only affected by dietary supplementation of medicinal plants. The highest amylase and alkaline protease activity were recorded in those fish received diet devoid on medicinal plants and stocked at 45 kg.m-3 (p<0.05). Those fish received diet containing medicinal plant powder significantly had lower activity (p<0.05). Proximal intestine histological examinations revealed that those fish stocked at higher density and received aflatoxin contaminated diet had villi detachments. Nevertheless, dietary inclusion of herbal blend consisted of rosemary and thyme powder could retrieve such tissue abnormality. It seemed that intestine could resist tension from higher stocking density or dietary aflatoxin contamination; however, their combination was not endurable for fish. Meanwhile, further complementary researches such as assaying antioxidant enzymes activity are warranted to precisely elucidate the underlying mechanism behind such alterations.

In this study, the toxicity of colloidal silver nanoparticles produced from three companies (US NANO, Pioneers, Nanonasb Pars) in the larvae of barnacles Amphibalanus amphitrite was evaluated using standard OECD. These crustaceans are important economically and ecologically. In this research, the LC50 within 24 hours for nauplius stages II, III, IV, V and VI examined against toxicity of the three types of silver colloidal nanoparticles. The results suggested that the calculated LC50 of silver nanoparticles from US NANO company for naupli II, III, IV, V and, VI, were 0.077, 0.046, 0.071, 0.006 and,0.009 mg/ml, respectively, and the LC50 of silver nanoparticles from Pioneers company for naupli II, III, IV, V and VI were 0.122,0.5, 0.402, 0.013 and, 0.023 mg/ml, respectively. The evaluated LC50 of silver nanoparticles from Nanonasb Pars for naupli, II, III, IV, V and VI were 0.259, 0.037, 0.018, 0.019 and, 0.017 mg/ml, respectively. This result indicated that silver nanoparticles of US NANO companys have been the most toxic on all larval barnacle stages and should be reviewed in correlation with the environment management products of silver nanoparticles.

The current study aimed to evaluate effects of four levels (0, 2, 4 and 6 % of diet) of soybean lecithin in the isoproteic and isoenergitic (50% protein and 18.5 kj/g) diets on growth performance, feed utilization and hematological parameters of juvenile sobaity seabream (Sparidentex hasta) with initial weight of 37.9±0.16 g. At the end of 56 days of feeding trial, results showed that growth performance increased with increasing dietary lecithin from 0 to 6%; however, growth decreased with increasing dietary lecithin from 6 to 9%. Fish fed the 6% lecithin diet had the highest final weight (86.19±2.99 g), weight gain (48.41±3.6 g) and specific growth rate (1.47±0.07) (p<0.05). Survival rate, feed conversion and protein efficiency ratios as well as hematological parameters were not changed in different groups (p>0.05). The results of this research showed that, inclusion of 6% of soybean lecithin in diet for sobaity seabream juvenile is optimum for improving growth performance parameters in this species.

This paper attempted to identify the effective factors and barriers on efficiency of the production section (canning and processing) the value chain of tuna and tuna like species in Iran. The present research is practical in terms of purpose and it is descriptive and survey in terms of collecting data. The statistical population of this research was board members, executive directors, the production managers and experts of tuna and tuna like species industries. The present research took place during the two-year period leading up to 1397. The data collection tool was a questionnaire which validity and reliability were confirmed. At first, by reviewing the literature and reviewing of the previous studies were identified 41 the effective factors and barriers of the value chain and after removing the repeat factors, 28 variables were extracted. Finally, using expert's opinions, 21 variables were identified as the effective factors and barriers which reduced the efficiency of the chain value of tuna and tuna like species in Iran. In the next step, using statistical analysis and applying the statistical test of the mark, 19 factors were identified as the main the effective factors and barriers and the ranking of these factors was done using Friedman test. It is determined that respectively, problems in supplying raw materials (quality, price and continuity and sustainability of supply), problems in providing financing and working capital, weakness in the production of diverse products according to the target market, high costs of selling the tuna products and lack of fair distribution of profits between different sectors of the tuna value chain have been 5 factors and barriers affecting on decreasing efficiency of the production section of the value chain of tuna and  tuna like species in Iran. With identifying these factors and prioritizing them, can be possible planning required for managing of these obstacles with the aim of increasing the efficiency of the production section of the value chain tuna and tuna like species and by providing appropriate solutions for handling higher priority barriers will be possible enhancing the efficiency of this industry and its economic sustainability in the future.

Water resources such as wetlands, in addition to their economic and social importance, are ecologically valuable sources of aquaculture production. Due to its effects on aquatic environments, necessity of monitoring and awareness of the spatial and temporal distribution of chlorophyll-a is important for environmental studies. In the new approach to such studies, application of spatial statistics has a special place. This study aims were to monitor the status of chlorophyll-a content in Choghakhor international wetland using spatial statistics and hot spots index based on remote sensing. For this purpose, satellite data of chlorophyll-a were prepared from Landsat 8 in 2017 and then analyzed using global and local spatial Moran of spatial statistics techniques. The results of global Moran showed strong correlation and data cluster distribution, which was the strongest in the spring and weakest attachment in the autumn. The results of local Moran showed a high number of high-dwarf clusters (levels of chlorophyll-a) in spring compared to autumn. This was more pronounced around the wetland, especially in the western and southern regions, which could be attributed to concentrated activities in these areas. Also, the impact and role of climatic and environmental factors around the wetland could be significant. Overall, the results of this study showed the efficiency of this statistic in identification of critical points and the appropriate separation based on the principles of spatial statistics and can serve as a model for other ecological parameters in other water resources.

The aims of present study were to investigate the effects of Chicory (Cichorium intybus L.) and Hypericum perforatum extracts on immune indices and antioxidant enzymes activity of rainbow trout (Oncorhynchus mykiss). For this purpose, 720 fish with an average weight of 100±5 g were randomly allocated to four distinct treatments including: a control group, 3% chicory extract, 3% extract of H. perforatum and combined treatment containing 1.5% chicory extract and 1.5% extract of ) H. perforatum). The experiments lasted for 12 weeks. Immune parameters including lysozyme, alternative complement activity and total immunoglobulin content of serum along with the activity of antioxidant enzymes namely catalase, superoxide dismutase and glutathione peroxidase were measured. Our results showed that dietary supplementation of 3% chicory extract significantly increased total immunoglobulin and lysozyme enzyme activity compared to the control group (p<0.05). The highest level of alternative complement activity was observed in simultaneous supplementation of 1.5% chicory and 1.5% H. perforatum extract (p<0.05). Also, single and combined dietary inclusion of both herbal extracts resulted in increased SOD and GPX enzymes activity in comparison to control group received diet devoid of any herbal extract (p<0.05). In addition, the highest and lowest activity of catalase was observed in the control group and 3% H. perforatum, respectively (p<0.05). In conclusion, dietary inclusion of 3% Chicory extract would improve the immune indices and including 3% H. perforatum extract increased the antioxidant enzymes activity of rainbow trout.

In order to study the capability of microalgea Chlorella vulgaris in removal of nitrate and phosphate from water, the effects of initial concentration of nitrate and phosphate and photoperiod were investigated in 20 experiments proposed by response surface methodology. The most effective factors in nitrate removal include initial nitrate concentration, photoperiod and interaction of phosphate-photoperiod. Highest capability of nitrate removal (49.42%) achieved at the initial nitrate concentration of 1500 mg/l, initial phosphate concentration of 40 mg/l and under 16h of photoperiod. Initial concentration of phosphate, photoperiod and interaction of nitrate-phosphate and phosphate-photoperiod were the main factors affecting phosphate capability of algea.  Highest capability of nitrate removal (41.61%) achieved at the initial nitrate concentration of 2250 mg/l, initial phosphate concentration of 60 mg/l and under 24h of photoperiod.

The quality of the oil extracted from rainbow trout (Oncorhynchus mykiss) wastes was evaluated using bioactive compounds of the plant thyme (Zataria multiflora). Three treatments were in this research: 1- Samples without extract or essence (control), 2-Samples with concentrations of 600 and 1200 ppm of extract and 3-Samples with concentrations of 600 and 1200 ppm of essence. The oil samples entered in test tubes which rapped in aluminum sheets and incubated in 50° C and analyzed on days 0, 3, 6 and 9. The results showed that chemical analysis of oils extracted from rainbow trout wastes including peroxide and non-enzymatic browning were lowest in 1200ppm of essence on day 9 of storage period while some other quantitative indices including thiobabrbitoric acid, free fatty acids and anisidine value were lowest in 600ppm of extract and essence on day 9. Comparing quantitative parameters in control and other treatments showed that almost all indices were higher in control indicating the antioxidant activity of the extract and essence of the plant they in reducing oxidative spoilage rate and increasing the shelf life of the oils.

Kaleybar Chay is one of the most important watersheds of the Aras River. For the first time, in order to identify the biology of Alburnoides bipunctatus and the level of infection by Ichthyophthirius multifilis in this river. Totally 53 Spirlin fish have been caught by hand nets in the specified station since fall 2016 to summer 2017. The all of them were caught alive and transferred to the laboratory in the specific containers and anesthetized via hitting their head and the type of fish was determined and the biometry indices were studied using identification keys. Microscopic examinations were conducted on the samples taken from the skin, fins and gills. The parasites were identified by diagnostic keys. Mean longitude and weight were 67±30 mm and 5.23±2 g respectively. The results of this study indicated the highest and lowest amount of feeding level were in winter and spring and the highest (42.85%) and the lowest (7.96%) infestation percent were seen in summer and autumn respectively. There was no infestation with parasites in winter. Of total of 53 specimens, 9 fish (16.98%) were infected with Ichthyophthirius multifilis. According to the findings, Spirlin fish was a benthivorous, detrivorous. Zooplanktons were not detected in the gut of Spirlin fish due to the small size of them and low planktonic resources. Therefore, zooplankton did not play a role in feeding of this fish.

The present study was performed with the aim of investigation in phenotypic variations of Cyprinus carpio as an economically worth species in south basin of the Caspian Sea. In winter of 2015, totally 74 specimens were collected from Anzali, Miankaleh and Gomishan and the morphometric information were extracted. The obtained results of ANOVA were indicated a high rate of phenotypic variations (23 out of 25). PCA detected HH1 (head height character) as the most important feature in making variations among populations. Cluster Analysis classified all samples in three major clades. So it can be concluded that there is at least three separate stocks of common carp in the southern basin of the Caspian Sea which it is high recommended that should be considered in stocks management in order to prevent subsequent problems including inbreeding and reduction in genetic fitness.