مجله علمی شیلات ایران
سال بیست و نهم شماره 4 (پیاپی 120، مهر و آبان 1399)

In this study has been attempted to evaluate some hematological, serological and immunological indices to determine the baseline for determining the health of SPF brood stock. For this purpose, during three sampling stages, before, simultaneously and after breeding time, the blood samples were collected from brood stock fish at the SPF center in the Cold water fisheries research Center (Tonekabon) and two elected farms (F and S). The fish of SPF center were supplied of the two others farms (F and S) and sampling were conducted from same folk at the SPF center and elected farms. Hematocrit, hemoglobin, total protein, albumin, alanine aminotransferase (ALT), aspartate amino transferees (AST), certain phosphokinase (CPK), alkaline phosphatase (ALP), total IgM and lysozyme were measured. The results showed that before the breeding season, the levels of hemoglobin, ALT and total IgM were not significantly different among the fish in the three centers, but the lysozyme levels of SPF center were significantly and numerically higher than S and F fish farms respectively. Statistical analysis of data showed that there were no significant differences in hematocrit, hemoglobin, total protein, albumin, IgM, AST, ALT and lysozyme levels among the three groups during the breeding season. The results after the breeding season showed that the hematocrit and weight of SPF fish were significantly higher than those two other groups but  hemoglobin, IgM and lysozyme levels were significantly and or numerically higher than those two other groups. Based on the results, it seems that the use of blood and serum indices can be used as a tool for health assessment condition, nutrition, rearing and hygiene managements. It seems that the health and nutrition management of the SPF center had been better than two other farms and it caused to improve the hemato- serological and immunological parameters of the SPF fish in compared to the other elected farms fish after breeding time.

Increasing the per capita consumption of shrimp in the country needs to examine consumer’s behavior, in this way, a product will be produced according to the interests of the consumption community and the barriers to consumption will be removed in the country. Since the behavior of consumers of one type of food (shrimp) may vary in different regions, assessing this difference will help provide strategies for increasing per capita consumption. The purpose of this study was to compare the behavior of shrimp consumers in three geographical regions of the country; coastal, central and mountainous regions. Data collection tool was a questionnaire (completed in the second half of 2019) and statistical analysis method was structural equation modeling (SEM). The results showed that in coastal areas, unlike the central and mountainous regions, the convenience of shrimp cooking and packaging did not have a significant effect on the attitude of the individuals as well as the access factor on the behavior control element. Further, it was found that in central and mountainous areas, in contrast to coastal areas, time and place of consumption are not effective on behavior control element. According to the results in coastal and mountainous areas, the most important variable affecting peoplechr('39')s attitude was the quality of shrimp, but in the central regions packaging variable replaced quality. In coastal and central areas, the effect of price on behavioral control was more pronounced than other factors but in mountainous areas, access was the most effective factor on behavior control element. According to the findings, in all three regions, supply and processing type as well as household income were positively and significantly influenced on attitude and behavior control element, respectively. Therefore, given the differences in shrimp consumerschr('39') behavior in the three regions, to increase per capita consumption, shrimp production and supply industry managers must adopt strategic policies appropriate to each regionchr('39')s target markets.

Yellowfin Tuna (Thunnus albacares) is one of the most important commercial and neritic fish species which has known because of ecological importance and wide distribution around the world. The aim of this study was to determine relative index of abundance for Yellowfin Tuna from 2007 to 2016, also we evaluated effect of some explanatory variables (year, month, vessel tonnage and net height) of catch per unit effort data in traditional gillnet fishery standardized by general linear model (GLM) in the Oman Sea. Standardized catch per unit effort is an important entrance in stock assessment as an annual abundance index. The results of this study have shown that all explanatory variables influence CPUE significantly in GLM model with lognormal error distribution; CPUE of Yellowfin Tuna increased 0.007 and0.0016 by raising one ton of vesselchr('39') tonnage and one meter of net height, respectively. Relative index of abundance of Yellowfin Tuna has the lowest quantity in 2011, remain stable till 2013 then increase to highest level in 2016, which is shown the catch rate can increase by raising catch effort. There is a seasonal trend in standard CPUE of Yellowfin Tuna with the highest catch rate in cold season. Monthly relative index of abundance has shown highest catch rate occurred in February and March.

In this study the effects of different algal and nonalgal diets on density and population growth rate of cyclopoid copepod Acanthocyclops trajani were studied. To this intention, the copepod were mass cultured in 120 liter tanks by feeding on different diets (5 treatments, 3 replicate in each one) including fresh composition of microalgae: Scenedesmus obliquus and Spirulina maxima (LSS), dried compound of mentioned microalgae (1:1)(DSS), dried macroalgae Gracilaria corticata (DG), dried composition of vegetables(DV) (spinage, parsley and coriander) and slurry liquid manure(S) and the population density (nauplius, copepodid and adult) were studied by population (every 3 days during 1 month) sampling. The results indicated that the highest population density average (1445±298 ind/L), the highest growth rate (0/145/d) and the shortest population doubling time (4/76d) were obtained from dried microalgae complex diet which was significantly different from most of diets (p<0/05). On the basis of the results, there is the potential of the usage of dried microalgae to improve the culture density of the copepod during shortage or descending time of fresh microalgae.

The aim of this study was to identify different virulence pathogens using Real-Time PCR method for rapid and accurate detection of common viral diseases including Infectious Hematopoietic Necrosis (IHN), Viral Hemorrhagic Septicemia (VHS) and Infectious Pancreatic Necrosis disease (IPN) in rainbow trout broodstock have been the main generation of reproductive populations maintained in the national plan for production the Specific Pathogen Free (SPF) fish. For this purpose, sampling was carried out on selected farms approved by the National Veterinary Organization in the provinces of Mazandaran, Kohgiluyeh and Boyerahmad and West Azerbaijan. Sampling of fish was done in different age groups and organs and was immediately frozen in liquid nitrogen. RNA extraction and Real-Time PCR experiments were performed using primers for the diseases. The results obtained using Real-Time PCR testing of healthy and suspected viral fishes showed the presence of VHS and IHN viruses in a number of selected farms, while the pathogenic virus IPN not detected. Based on the results of this study, it seems that Real-Time PCR can be used as a rapid diagnostic method in screening tests for rainbow trout viruses and as a complementary method for virus detection in routine tissue culture experiments.

This study investigated the growth performance and fatty acid composition of Western whiteleg shrimp (Litopenaeus vannamei) fed with different levels of Dunaliella salina extract (DE) PL with an average weight of 0.86 ± 0.01g were fed with 3 types of diets containing 0.5, 1.5 and 1.5 g DE /kg diet and control diet (without DE) for 60 days. (A total of 4 treatments and 3 repetitions per treatment). The best weight gain (141.38 ± 21.35%), specific growth ratio (1.69 ± 0.55%) and protein efficiency ratio (2.79± 0.42%) were observed in shrimp fed with 1 g/kg of DE diet. In diets containing 0.5 and 1 g DE/kg feed, poly unsaturated fatty acid (PUFA) value significantly increased (p<0.05). Arachidonic acid (C20:4n-6), linoleic acid (C20:2n-6) and Docosahexaenoic acid (C22:5n-3) levels of shrimp receiving at 0.5 and 1 g DE/kg feed level were significantly higher than those fed with control diet(p<0.05). In conclusion, the incorporation of extract from D.salina 1 g/kg doses improves function of growth and fatty acid composition of body in L. vannamei shrimp.

In this study, the antioxidant effects of Thyme (Zataria multiflora), Shallot (Allium ascalonicum) and Turmeric(Curcuma longa)extracts(1.5% volumetric-volumetric) on shelf life of Oncorhynchus mykiss during storage at refrigerator temperature for a period of 20 days was compared. Peroxide index, thiobarbituric acid index, volatile nitrogen compounds and free fatty acids along with pH were measured in fillet samples. The results showed that thyme extract significantly delayed the oxidation of the fillet (p<0.05). Also, the fillet treated with thyme extract was of the required quality for consumption compared to the control sample and other treatments until the end of the storage period. The results showed that the addition of thyme extract due to its antioxidant properties increases the shelf life of samples treated with this extract.

To achieve comprehensive management of marine resource stocks requires knowledge of the variables that affect economic species. Longtail tuna (Thunnus tonggol) is one of the most economic species in the southern waters of Iran. Recent study tried to find out the association between the most important satellites derived environmental variables with longtail tuna catch and distribution by applying Generalized Additive Model (GAM) in the southern waters of Iran. Results indicated the relatively high importance of temporal (month of fishing), spatial (latitude), and three environmental variables as Sea surface salinity (SSS), mixed layer depth (MLD), and Sea surface temperature (SST). Deviance explanation of the GAM model defined as 62.3% and adjusted R-square was 0.595. Maximum Entropy (MaxEnt) habitat suitability modeling by selected tree environmental variables shows longtail tuna inhabited mostly in latitude between 24°N and 26°N close to Hormozgan and Sistan and Balochistan province waters. The current study by detecting most important satellite derived environmental variables and high suitable habitat, could assist decision makers and fishery managers to improve fishing efficiency of Iranian purse seiners and helps implementation of ecosystem-based fisheries management of shared stocks in southern waters of Iranian.

Algae and seaweeds and their metabolites have been considered as promising alternatives in improvement of fish immune system and growth. The effects of extract and fucoidan extracted from Sargassum sp. was investigated in Nile tilapia with an average weight of 25 ± 5 for 60 days. The experimental groups included 0.5%, 1% and 2% of extract, and 0.5%, 1% and 2% of fucoidan. A group fed with basal diet was considered as control. In order to investigate the growth and immunity parameters, sampling was carried out on days 30th and 60th of the experiment. The results of this study showed that fucoidan and extract from Sargassum had no significant effects on gained weight, specific growth rate and feed conversion ratio after 60 days feeding (P>0.05). The amount of lysozyme as an important immunity parameter also did not significantly differ between the sampling times among the treatments (P>0.05). Also, there was no significant difference in serum total protein, albumin, globulin, cholesterol, triglyceride, alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase levels among the groups after 30 and 60 days of experiment (P>0.05). Besides, the results of antioxidant parameters including superoxide dismutase, peroxidase and catalase enzymes did not show significant differences among the experimental groups at days 30 and 60 (P>0.05). Although inclusion of Sargassum did not have negative effect on growth rate of tilapia, it did not improve immunity of tilapia. Therefore, it is recommended to examine a wider range of concentrations of extract and fucoidan in future studies.

Malabar trevally is one of the species of Carangidae family in the Persian Gulf and Oman Sea, which biological and population characteristics of this species were less been studied . In this regard, reproductive indices such as gonadosomatic, first maturity length, sex ratio, spawning season, absolute and relative fecundity were investigated. Reproduction studies of Malabar trevally (Carangoides malabaricus) were carried out in the waters of Hormozgan province from December 2016 to November 2017. Samples were collected monthly using trawl nets. Total, fork length and weight were measured. In this study, the total samples were 438, out of which 258 were females, 150 males and 30 immature. The minimum and maximum average fish fork length during the different months was 14-34 and 26.42±3.33 cm, respectively. The maturity female fork length (LM50) was 180 mm.  The sex ratio of female to male was 1.72 to 1 which showed a significant difference (P<0.05). Maximum absolute fecundity was 185432±8127 eggs in April and maximum relative fecundity of 570 23 eggs per gram in April. The minimum absolute fecundity was 66542±14197 in September and the minimum relative fecundity of 130 14 eggs per gram in June. The maximum GSI index of female and male fish were calculated 1.8 and 0.68 in March respectively which spawning could be started from April.

Occurrence and abundance of Microplastics (MPs) were studied in sediments of the Anzali wetland for the first time in spring 2018. Sediment samplings were carried out using Van Ween Grab. After density separation in saline solution, MPs were counted by a stereomicroscope. The number of MPs was at the range of 14-282 items/100g dry sediment (140-2820 items/kg dry sediment). Stations 10 and 9 with 282 ± 171.14 and 14 ± 3 items/100g dry sediment exhibited the highest and lowest contaminations, respectively. The MPs gathered during the survey varied in size from 0.3 to 5 mm, and those with 1–2 mm in size had the highest frequency (37.3%). The dominant shape of MPs was fiber; Followed by fragments and films. Red, black, and blue were the most abundant colors by 34.1%, 30.8% and 26.4%, respectively. In total, 5 microplastic polymers including polystyrene (PS), polypropylene (PP), polyester (PEST), polyethylene (PE) and poly acrylonitrile (PAN) were identified. This first work provides original data on the presence of MPs, determining their bioavailability to organisms as seafood, and then possible transfer to human. The results provide useful information for further studies.

In this study, the effect of vermicompost fertilizer and other organic fertilizers on plankton abundance, growth indices and survival of Caspian kutum fry was studied. For this purpose, Caspian Kutum fry with an initial weight of 0.15 ± 0.01 g (mean ± standard deviation) were obtained from the Shahid Rajaee fish hatchery center (Sari, Mazandaran) and transferred to a fish farm. Fish were acclimatized to the experimental conditions for two weeks. After acclimation, these fish were divided into 7 experimental treatments: control treatment (C) : no fertilizer, treatment 1 (T1): vermicompost 10 ton / hectare (1 kg / m3), treatment 2 (T2): vermicompost 15 ton / hectare (1.5 kg / m3), treatment 3 (T3): 10 ton compost / hectare (1 kg / m3), treatment 4 (T4): compost 15 ton / hectare (1.5 kg / m3), treatment 5 (T5): cow manure 10 ton / hectare (1 kg / m3), treatment 6 (T6): poultry manure 5 ton / hectare (0.5 kg / m3). The fish, with a mean weight of 0.15 ± 0.01 g, were reared for 60 days in fiberglass tanks. The results showed that application of organic fertilizers had a significant effect on growth indices. The best growth and survival performance was observed in the treatment of vermicomposting 10 ton/ha and poultry manure. Plankton populations were affected by the amount and types of organic fertilizers and the highest phytoplanktonic and zooplanktonic populations were observed in vermicomposting 10 ton/ha and poultry manure treatments. These results suggested that 10 tons per hectare of vermicompost has positive effect on growth parameters and plankton water population in fish breeding of Caspian kutum.

Water quality index is a tool that integrates data of effective factors on water quality. The final result of the index provides simple understanding of water quality for general people. Regarding the importance and application of water quality index in decision making of active and executive units in conservation and exploitation, the present study was conducted for the first time in the southern of Caspian Sea. The aims of paper are to determine: the environmental parameters which are important in water quality, determining weight (wi) of parameters affecting water quality index and sub-indices (qi) of each important parameters of Caspian Sea water quality index (WQIcs). This research will provide the specific and necessary information and data for calculating the water quality index in this aquatic ecosystem. The provided wi and qi were applied for water quality index calculating of the Caspian Sea data in 2018-2019. Using Principal Component Analysis results on long-term data 2003-2019 years (920 water samples), 9 important parameters (turbidity, chlorophyll-a, BOD5, COD, pH, DO%, NO3, NH4 and PO4) were determined for WQIcs and indicator weighting (wi) of each parameter was determined. The sub-index (qi) of each parameter was calculated based on standards threshold, coastal water quality requirements in marine ecosystems and reference value data of Caspian Sea. Finally, by calculating the geometric mean, the value of water quality index in the Caspian coastal waters was obtained. The application of this formula in 2018-2019 showed that 74 and 26% of WQIcs were in the range of 70-91 (medium class) and 35-69 (bad class), respectively. Among the 9 parameters mentioned above, nitrate and phosphorus (the factors of trophic enrichment) had the greatest effect on decreasing water quality index.

Determination of trophic status is one of the methods for assessing ecological balance of wetland ecosystems, because sustainability and productivity based on these unique ecosystems require proper monitoring and control of their environmental conditions. Therefore, biological and ecological studies are necessary before any activity is established. Tanudar Wetland with an area of 1000 hectares is one of the largest wetlands of Lorestan Province, 10 km northwest of Dorood. In this study, physical and chemical characteristics of Tondar wetland sampling were used to evaluate the nutritional status of Carlson (TSI) based on total phosphate (TP), total nitrogen (TN) and phosphorus to nitrogen (PN) Sampling of Tanudar wetland was used in summer of 2019. The results showed that based on the Carlson Trophic Index (TSI), trophic wetland Tanudar level is in eutrophic conditions. wetland Tanudar to its location, natural conditions and hydrological conditions, the is mainly drained from the highlands of Silakhor plain and tira River Dorood, Therefore, any upstream loading such as orchard development, diversified recreational harvests in the river, increased levels of dark river water pollution caused by municipal, industrial wastewater, and point source pollution sources such as warm-water fish ponds have crossed the Tanudar wetland. And it wound deeper on the current unstable body. Therefore, in the current conditions, the quantitative and qualitative provision of the wetland ecological right of the wetland is one of the most obvious requirements and management issues of the wetland.

The present study was carried out to determine the effect of different levels of glucose and corn starch as carbohydrate sources on growth performance, body composition, digestibility, digestive and liver enzymes of Siberian sturgeon (Acipenser baerii). A total number of 120 Siberian sturgeons weighing 25.64 ± 2.80g were fed four diets including glucose 15%, glucose 30%, corn starch 15% and corn starch 30% for a period of 11 weeks. Results showed that final weight, final total length, percentage of body weight increase, specific growth rate, mean daily growth, protein efficiency ratio and condition factor in fish fed corn starch 15% were high in comparison with other treatments (P>0.05). Significant difference was seen between fish fed corn starch 30% with fish fed glucose 15% in hepatosomatic index (P<0.05). The highest content of carcass protein was seen in corn starch 15% that showed significant difference with glucose 15% and 30% (P<0.05). Fish fed glucose 15% had the highest content of carcass total carbohydrate which showed significant difference with corn starch 15% and 30% (P<0.05). The contents of lipase, pepsin, trypsin and chymotrypsin enzymes and also apparent digestibility of protein and lipid in fish fed corn starch 15% were higher than the other treatments (P<0.05). The highest contents of liver enzymes were recorded in fish fed glucose 30% (P>0.05). Based on the mentioned results, corn starch at the level of 15% can increase growth and improve body composition, digestibility and digestive enzymes in Siberian sturgeon.

This study was carried out to investigate the different cooking methods on some physicochemical properties and fatty acids composition of narrow-clawed crayfish (Astacus leptodactylus). In this study, four cooking methods including grilling, boiling, frying, and cooking in microwave with three repetitions were performed for 84 pieces of crayfish caught from Aras Dam. The results of the study of physicochemical properties showed that the maximum and minimum amounts of protein content were obtained in steamed (17.70±0.39 %) and deep-fried (15.13±0.14 %) groups, respectively. The highest level of fat was recorded in the deep-fried method (7.36±0.25 %) and there was no significant difference among the other treatments (P>0.05). The highest amount of pH was observed in steamed treatment. According to the results of cooking loss, the highest value was observed in the microwaved method, while the deep-fried and grilled treatments had the least value. Also, the results of texture profile analysis showed that the highest hardness 1 and 2 were observed in deep-fried treatment (P<0.05). Fatty acids composition results showed that the highest values of eicosapentaenoic acid (20.25±0.13 %) and docosahexaenoic acid (6.31±0.26 %) were recorded in the steamed method and the lowest values was observed in deep-fried treatment (P<0.05). Therefore, it can be concluded that the steamed cooking method had less negative impact on the nutritional value and physicochemical properties and the reduction of unsaturated fatty acids of freshwater narrow-clawed crayfish tail meat than other cooking methods.

Knowledge of environmental parameters affecting on distribution of aquatics and their realms can help maintain and correctly manage aquatic reserves. Lack of enough data on the presence of fishes in the Persian Gulf has turned into a problem. The prediction of species distribution in a large scale has become possible using the remote sensing technologies. The present study aimed to model and depict the spatial distribution of Narrow-barred Spanish mackerel (Scomberomorus commerson) in the Persian Gulf using logistic regression. The presence coordinates of the animal were downloaded from GBIF. The raster layers of 11 environmental parameters were procured from the Modis sensor website of NASA. Models were made in R. The accuracy of the models was examined using the area underneath of the ROC.  The probability of presence of S. commerson was mapped. Depth and particulate organic carbon were the most important factors shaping the spatial distribution of this species.

The present study was conducted to evaluate the effect of agar-gelatin nanocomposite film with peppermint essential oil (Mentha piperital) on the quality of rainbow trout fillets (Oncorhynchus mykiss .( The samples were divided into 5 groups of agar-gelatin nanocomposite film (treatment 1), agar-gelatin nanocomposite film with 0.5% essential oil (treatment 2), film with 1% essential oil (treatment 3), film with 1.5 Essential oil (treatment 4), film with 2% essential oil (treatment 5). Essential analysis showed that menthol with 49.7% of the main composition of peppermint essential oil. Samples were stored in the refrigerator for 15 days and at certain intervals (days 0, 3, 6, 9, 12 and 15) for microbiological, chemical (pH, TBA, PV, TVB-N) and sensory tests were evaluated. Bacterial results showed that treatments 1 and 2 did not significantly reduce the number of bacteria in comparison with 3, 4 and 5 treatments. The pH of the rainbow trout fillets was not significantly affected by essential oil .TVB-N, TBA and FFA showed the least amount of this indicator in both treatments 1 and 2. However, regarding the total peroxide value and total microbial load, adding essential oil to the film caused a significant reduction in this index with non-essential oil. In all parameters, the lowest level was observed in the treatment with the highest level of essential oil. Significant difference was not significant between the 5 treatments. Based on 2 TVB-N and TVC indexes, treatments 1 (agar-gelatin nanocomposite film) and treatment 2 (agar-gelatin nanocomposite film) containing 0.5% peppermint essential oil were treated to 6, 3, 4 and 5 (Agar-gelatin nanocomposite film) containing 1, 1.5 and 2% peppermint essential oil were allowed to use until the 9th day. According to the present study, agar-gelatin foil nanocomposite alone did not have the ability to increase the shelf-life of rainbow trout, but the addition of peppermint essential oil (at levels 1, 1.5 and 2%) was able to increase the duration Shelf life was effective for 3 days.