مجله علمی شیلات ایران
سال سی و دوم شماره 5 (پیاپی 139، آذر و دی 1402)

The present research was started in 2016 at Bandar Imam Khomeini Marine Fish Research Station. The aim of this project was to produce fertile broodstock and achieve the biotechnique of larval propagation and fry production of the Asian sea bass. In this regard, the Thai fry strain were introduced in the station over three different years and their breeding was done until the pre-breeding stage. After four years, 3- and 4-year-old female pre-brooders and 1.5-year-old male pre-brooders were produced, and in the summer of 2022, these brooders were propagated by artificial reproduction method through injecting. In Khuzestan, the reproduction season begins from June to the end of September at a temperature between 28 and 34 ºC. The fish spawning occurs between 36 and 40 h after injection at midnight. The LHRH-α2 hormone was injected intramuscularly for the artificial reproduction of this species. The percentage of fertilization, hatching, and survival of 3-day-old larvae of Asian sea bass in different months varied between 78-92%, 82-93%, and 75-85%, respectively. From February 2022 to July 2023, 208 brooders were donated to 5 private hatchery sectors in Khuzestan and Hormozgan provinces for the mass seed production of this species. The results of the current project showed that the establishment of biosecurity is the most important principle in the implementation of breeding programs, domestication of new marine fish candidates, and selective breeding programs. Also, Asian sea bass has great potential for reproduction in captivity and mass fry production, and it can help short-term programs for the development of marine cage culture in the southern waters of Iran.

Considering the role of seafood consumption in providing public health as well as the increase in the elderly population in Iran, the attitude of the elderly towards the consumption of fresh fish and the factors affecting it were investigated in this research. For this purpose, a questionnaire was designed and standardized based on the library study and the opinions of experts. Questionnaires were sent electronically through cyberspace to elderly people (age 60 and above). SPSS software was used for descriptive statistical analysis and the structural equation model was used in Lisrel software for the intensity of the relationship between the structures. Based on a default model of consumer behavior, the results showed that 7 factors of quality, type of supply, income, access, experimental records, health, and convenience of consumption are significantly effective on the attitude of the elderly towards the consumption of fresh fish (p<0.05). Instead, the two factors of price and advertising did not have a significant effect on the attitude and it was found that the attitude of the elderly towards the consumption of fresh fish is effective on their decision to buy and increase their fish consumption (p<0.05), in this way, by changing and improving each of the factors affecting the attitude, it is possible to increase fish consumption in the elderly. Quality and access were among the most effective factors in the elderly's desire to consume fresh fish. Therefore, by improving the quality and increasing access to fresh fish in different regions of the country, an important step can be taken to facilitate and increase the consumption of fresh fish by the elderly.

The aim of this study was to investigate the effect of shrimp farm effluent on the diversity and density of macrobenthic communities of Delwar coast (Bushehr province). For this purpose, sampling was performed by Van Veen Grab sampler (15 x 15 cm2) during the farming period for 8 months (from May to October and two months including April and November as a control) from Delwar beach sediments (6 stations and 3 repetitions for each station). Also, the granularity of bed sediments, soil texture, and total organic matter (TOM) of sediments were measured. In this research, 15 families of benthic invertebrates were identified in 7 orders and 5 categories. Also, the examination of the changes in the detected benthic organisms showed that the maximum density was in April (103±82 N/m2) and the minimum density was in July (70±41 N/m2). Also, station five with 115±40 N/m2and station one with 62±40 N/m2had the highest and lowest density, respectively, and the total density of benthic invertebrates for 8 months of sampling was 15490±581N/m2. The results of this research show that the effect of shrimp farming effluents on the abundance of microbial organisms in Delwar coast is remarkable.

Chlorella vulgaris is a freshwater green microalgae, which is a rich source of novel structural and biologically active metabolites. In this research, the extraction of Chlorella vulgaris polysaccharides was done by hot water method and the crude polysaccharide yield was approximately 5% of dry weight. Antioxidant activity of the polysaccharide extracted by the methods of inhibiting 2, 2-diphenyl-1-picrylhydrazyl radicals (DPPH) and reducing power in 5 concentrations (0.375, 0.75, 1.5, 3 and 6 mg/ml) was investigated. The obtained polysaccharides had antioxidant activity. The highest DPPH inhibition activity was 15.91% at 6 mg/ml and the highest reducing power was 0.781 at 6 mg/ml (absorbance at 600 nm). DPPH free radical inhibition and BHA reduction power at the concentration of 0.031 mg/ml were 39.78% and 3.65, respectively. The value of IC50 for DPPH free radical inhibition and reducing power of Chlorella vulgaris polysaccharides was 22.342 and 45.79, respectively. Also, the polysaccharide of Chlorella vulgaris had an inhibitory effect of 21% on E. coli compared to the control culture after 18 hours of incubation. C. vulgaris microalgae polysaccharides contain a wide range of bioactive compounds, in food supplements they will be an effective mediator in scavenging free radicals and have the potential to be created as natural antioxidants for use in food and medicine industries.

Natural habitats around the world have suffered a lot of pressure due to the increase in human industrial activities in order to achieve economic-welfare goals, by changing in the climate system, and the consequences of this event include the extinction of species and the reduction of biodiversity on a global scale. In this regard, the evaluation of the threats resulting from the changes created in the ecosystems will be pivotal to their management and conservation. In this study, the distribution of Rutilus kutum was predicted under two optimistic and pessimistic scenarios of 2050 and 2080 by Maxent model. In this study, the set of data collected by the authors and various available scientific sources from a period of 50 years (1970 to 2020 AD) was used. Also, the environmental and climate variables used in the modeling were extracted and prepared from www.worldclim.org.The results showed that the performance of the model in predicting species distribution was excellent (0.946) based on the AUC (Area Under the Curve) criterion. In addition, it is predicted that the distribution of the species is likely to decrease significantly in all years and optimistic and pessimistic scenarios. Therefore, considering the importance of the sim species in the food basket and its positive effect on the livelihoods of local communities, reducing its distribution in the future could be considered a threat to food security. In conclusion, the protection of this species requires urgent planning, actionable decisions and effective measures regarding the preservation and restoration of rivers, controlling the negative effects of climate change and efforts to reduce the accelerating factors of this critical phenomenon.

Due to its unique climate, the province of Kohgiluyeh and Boyar Ahmad has a lot of potential in aquaculture. However, due to the lack of knowledge of water resources in different climates of the province, a large part of these resources, are unused, especially in tropical regions, which can be used for fish farming, including sturgeon fish. In this regard, the investigation of the khairabad river in the cities of Gachsaran were done in this project. For this purpose, the investigation of Khairabad river in Gachsaran city was investigated.  after identifying the research stations, regular sampling was done to check the physicochemical characteristics of water and as well as record and analyze meteorological and climatic data. The temperature was 18-23°C, pH in the range of 7-8, hardness 453-238 mg/l, phosphorus 0.2-0.6 mg/l, nitrate and nitrite  respectively were in the range of 1.2 to 1.2 and 0.01 to 0.06 mg/l. The BOD level was below 10 mg/l, which is considered as a relatively polluted river. Also, the COD and EC levels were meseaured 6-25 mg/l and 542-1433 µS/cm, respectively. The results indicated that the most suitable area for sturgeon farming is downstream of Khairabad river, which of course requires the use of various mechanization methods to reduce the bacterial load of water, remove heavy metals, aeration and also use wells. It is a drain. Considering that in the lower reaches of the Khairabad river, the distance from the outlet of the Kausar Dam to the area of Masoum Abad village, near the border of Kohgiluyeh and Boyer Ahmad provinces with Khuzestan province (about 20 km), the maximum flow that can be used for sturgeon farming, especially bleuga, is about 1.5 m3/s (50% of the minimum discharge in the summer) and taking into account 4.5 l/s of water for the production of 1000 kg of sturgeon fish and also Keeping a distance of about 5 km for the construction of sturgeon farms in order to maximize the self-purification of the river, it is possible to issue a license to build 4 farms with a total production capacity of 1200 tons of beluga.

The purpose of this research is to investigate the nutritional value (approximate composition, amino acid and fatty acid), phytochemical (sterol, phenol and flavonoid) and antioxidant activity (diphenylpicrylhydrazyl; DPPH) of mixed aqueous extract of brown macroalgae Sargassum ilicifolium, Nizimuddinia zanardini, Cystoseira indica, and  Padina australis. In this study, after collecting the macroalgae, they were washed and dried, and then they were combined in a quantitative ratio of 1:1:1 and turned into powder. The amount of protein, fat, carbohydrates, ash, moisture, and  the amount of raw energy are 6.38, 1.30, 0.86, 5.10, 2.20, 85.46 g/100 g wet weight of the mixture, and 4238.86 cal/g respectively. The predominant saturated fatty acids in the tested macroalgae mixture were palmitic acid (15.11±0.89%), myristic acid (10.51±0.28%) and stearic acid (8.54±0.43%), respectively. Among the long chain unsaturated fatty acids (PUFA), arachidonic acid (20.48±4.23%), linoleic acid (18.32±6.12%) and alpha-linolenic acid (6.50±0.78%) were dominant respectively. The total amount of essential and non-essential amino acids was 7.88 and 11.41 amino acids/100 g of sample, respectively. Glutamic acid (4.12±0.02 g AA/100 g of sample), aspartic acid (1.71±0.05 g AA/100 g of sample) and serine (1.64±0.09 g AA/100 g of sample) by non-essential amino acid were dominant respectively. The predominant sterol was sitostanol. The amount of total sterol was 234.54 ± 12.18 mg/100 g dry matter. The amount of phenol, flavonoid and antioxidant activity of mixed aqueous extract, was 83.46.7 ± 7 mg GAE /g of extract, 10.01 ± 0.98 mg of QE g dry extract and 1323.87 ± 11.28 µmol TE/g respectively. Overall, the results of this study showed that due to the presence of PUFA, the balance between essential and essential amino acids, sterols and natural antioxidants, using the macroalgae mixture of S. ilicifolium, N. zanardini, C. indica and P. australisis recommended in food and pharmaceutical industries.

In this study, the effects of cobalt chloride (CoCl2) with two levels of 2 and 4 mg/kg and vitamin C with two levels of 200 and 800 mg/kg diet and their combined levels in 9 treatments and each treatment with 3 repelications on 270 Siberian sturgeon (Acipenser baerii) with an initial average weight of 11.51±0.29 g were evaluated for 12 weeks. Based on the results, the mean final weight and length of the fish in 4 mg/kg CoCl2 were significantly higher than the control group (p<0.05). There was no significant difference in the weight gain, body weight gain and food conversion ratio between the treatments and the control group (p>0.05). The results of blood and biochemical indices showed that the highest number of red and white blood cells was observed in the treatments of 2 mg/kg CoCl2+200 and 800 mg/kg vitamin C, respectively. The highest percentage of neutrophils was observed in 800 mg/kg vitamin C treatment, which showed a significant difference with treatments 2 CoCl2, 800 C+4 CoCl2, 800 C+2 CoCl2, 200 C+4 CoCl2 and control (p<0.05). There was a significant difference in the percentage of lymphocytes in 800 mg/kg vitamin C and 800 mg/kg vitamin C + 2 mg/kg CoCl2 treatments compared to the control group (p<0.05). The lowest percentage of monocytes was in the control group (p<0.05). The highest percentage of eosinophils was found in 800 mg/kg vitamin C and 800 mg/kg vitamin C + 2 mg/kg CoCl2 treatments compared to the control group and other treatments (p<0.05). The highest amount of triglyceride and cholesterol was observed in the concentrations of 200 mg/kg vitamin C+4 mg/kg CoCl2 and 4 mg/kg CoCl2, respectively (p<0.05). The results showed that the use of vitamin C and cobalt chloride separately and in combination in the desired weight range had significant effects on growth parameters during the culture period. The effect of vitamin C on some growth and blood indices was higher compared to cobalt chloride. The positive effects of combined treatments were more than individual treatments in most indices. Finally, the diet containing 200 mg/kg vitamin C+4 mg/kg CoCl2 was considered suitable for growth of juvenile Siberian sturgeon.

In this study, the effect of the effluent from rainbow trout ponds was investigated on the yield, concentration and uptake of nitrogen, phosphorus and micronutrients on the silage corn in the Golpayegan research station for Husbandry and Agriculture in Isfahan. 45000 fish with an average weight of 10 ± 2 g were uniformly divided in 9 ponds (20 × 2.2 × 1.3 m) for six months. The research was conducted in a complete randomized block design with five treatments in triplicate. The treatments were included 1) irrigation with well water without any fertilizer as the control, 2) irrigation with well water and use of urea, triple superphosphate and potassium sulfate as the fertilizers, 3) irrigation with fish ponds effluents without any fertilizer, 4) irrigation with fish ponds effluents and use of the fertilizer, and 5) irrigation with fish ponds effluents with 50 percent of the fertilizer. Results showed that the use of fish ponds effluents significantly caused increasing in corn yield and concentration of zinc, cupper, nitrogen, phosphorus, manganese and iron (p<0.05). In addition, using fish ponds effluents with the 50% of chemical fertilizer led to increase corn yield by 44 percent compared to the control group (p<0.05). Moreover, the uptake of iron, zinc, copper and manganese by corn were increased significantly compared to the control group through use of fish ponds effluents water with fertilizer (p<0.05). The highest and lowest yield of corn was obtained in the irrigation with the effluent of fish ponds effluents coupled with chemical fertilizers and the control group, equal to 73.7 and 44.4 tons per hectare, respectively, which had significant difference with each other (p<0.05). Therefore, the use of fish farm effluents for production of corn not only increased the yield but also dramatically enhanced fertilizer utilization.

The natural products of seaweeds have been taken into consideration due to their application in various fields of medicine, nutrition, and agriculture in the world. Recent research has shown that marine metabolites can form the future of the bioeconomy. There are many populations of Ulva and Sargassum algae on the southern coasts of Iran, and therefore, in this research, the populations of U. lactuca and S. vulgare were collected from the shores of Bushehr, and their photosynthetic pigments, soluble carbohydrates, total protein and compounds in essential oils were investigated in the winter and spring seasons. The results showed that S. vulgare in spring and U. lactuca in winter had the highest amount of chlorophylls and total carotenoids. The amount of soluble carbohydrates in U. lactuca significantly increased in spring compared to winter. The amount of total protein in both species significantly increased in winter compared to spring. The main components of the essential oils of both species included alkane hydrocarbons, which often had a higher abundance percentage in winter. In spring, fatty acids and aromatic compounds with phenyl ring(s) were observed in the essential oils of these species. Considering the changes in the content of metabolites in these species along with seasonal changes, the present results can be effective in the targeted selection of algal species and the appropriate harvesting time for special applications.