فهرست مطالب سراج بیتا

Fish are a significant dietary source of various minerals essential for human health. This study examined the mineral profile (sodium, potassium, calcium, magnesium, iron, zinc, copper, iodine, selenium, and chromium) and harmful trace elements (mercury, lead, cadmium, and arsenic) in different parts of the bigeye ilisha (Ilisha megaloptera), including the backbone, head, abdominal fin and viscera, caudal fin, and fillet, from the northern coast of the Oman Sea. Results revealed significant variations in element concentrations among different parts, with higher mineral levels often found in waste parts compared to the fillet. Most minerals were present in amounts exceeding human dietary requirements, suggesting that processing waste parts of bigeye ilisha could be beneficial as food or dietary supplements. Additionally, the levels of harmful elements—mercury, lead, cadmium, and arsenic—were below permissible limits for human consumption. These findings support the potential for developing value-added products from bigeye ilisha.

In the present study, the amount of proximate composition (protein, lipid, moisture, and ash) and the profile (quantity and quality) of fatty acids and amino acids in different parts of bigeye ilisha (Ilisha megaloptera) including (backbone, head, abdominal fin and viscera, caudal fin and fillet) were measured. The results of proximate composition showed that the amount of these compounds in different parts differed significantly and in many cases, the amount of macronutrients in waste parts was higher than fillet. The results of the analysis of fatty acids showed that different parts of the bigeye ilisha contain high levels of lipids rich in omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFAs) and long chain monounsaturated fatty acids (LC MUFAs). Among PUFAs, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) had the highest percentages compared to other polyunsaturated fatty acids. The highest amount of EPA and DHA was found in the abdominal fin and viscera, respectively, equal to 1.986 g/100g (13.61% of total fatty acids) and 5.124 g/100g (35.11%). The ratio of omega-3 to omega-6 fatty acids (n-3/n-6) was different in different parts of the body, and the highest ratio was 17.433 in the abdominal fin and viscera. The highest percentage of the total essential amino acids was also present in the abdominal fin and viscera (43.14%). The lowest percentage of essential amino acids with the amount of 39.66% was found in the caudal fin. The amount of all essential amino acids in all cuts of bigeye ilisha was significantly higher than the amount recommended by FAO/WHO. The results of the present study showed that different parts of bigeye ilisha can be an ideal source of long-chain polyunsaturated fatty acids and essential amino acids.

In light of limited biological data, particularly concerning the dietary habits of four-lined terapon fish (Pelates quadrilineatus), a comprehensive study was conducted. A total of 140 fish samples were gathered from various points along the Makkoran coast, including the Chabahar fish market and catch unloading centers in Chabahar, Ramin, and Tis. The investigation aimed to delineate their seasonal feeding patterns from the onset of summer 2019 until the conclusion of spring 2020. The findings revealed the average total length and weight of the fish to be 18.51±4.13 cm and 82.30±16.71 grams, respectively. Moreover, the average relative length of the intestine and stomach fullness/emptiness stood at 0.52% and 49.29%, respectively, indicating the species' carnivorous nature and moderate feeding tendencies. Notably, gastro-somatic index, feeding intensity, and condition factor during autumn were significantly lower than in other seasons, with averages of 1.48±0.24, 95.34±25.11, and 0.72±0.068, respectively (p<0.05). Assessment of food preference and relative importance unveiled mollusks and crustaceans as primary dietary components, with copepods, polychaetes, and fish identified as secondary sources for this species. Among mollusks and crustaceans, the gastropod and hermit crab held the greatest significance, accounting for 41% and 42% of the P. quadrilineatus' diet, respectively. Overall, the feeding indicators suggest that this species thrives as a carnivorous fish, exhibiting moderate feeding habits and favorable living conditions in the coastal waters of Makkoran

Considering that the tuna fishes are used as raw material for canning therefore it is necessary to identify the suitable method of catching and keeping them in order to maintain thequality of the raw material. Usually, changes in fish after catching until consumption or processing may be due to reasons such as chemical and enzymatic reactions, oxidative spoilage and bacterial growth, which cause the production and increase of some chemical compounds such as total volatile nitrogen, peroxide number, thiobarbituric acid, change in pH results in a decrease in the quality and shelf life of the fish (Rezaei and Hosseini, 2008), so the proper method of fishing and the correct method of storage and transportation after catching can play an important role in controlling these changes and creating the desired quality in fish and its products include canned fish. The principle components of this fishes muscles are water, fat, protein, minerals and vitamin compounds. Biochemical methods based on production of trimethylamine (TMA), total volatile basic nitrogen (TVB-N) and lipid oxidation have also commonly used to evaluate fish quality (Jinadasa et al., 2015). Thunnus tonggol and Thunnus albacares belongs to the family Scombridae and they are pelagic large size marine fish (Jinadasa et al., 2015).. Thunnus tonggol and Thunnus albacares fisheries are of crucial importance to Iran due to their economic importance of fresh, frozen and canning trade. The aim of this study is therefore to determine the nutritional value and quality of the Thunnus tonggol and Thunnus albacares that landed in Chabahr coast using somechemical indices, to established the limit of acceptability and determine if the type of catching and storage as effects on the rate of deterioration.

The samples studied in the present research are Thunnus tonggol and Thunnus albacares fishes with average length and weight of 69.50±2.62 cm and 4123±69.45 gr and 75.00±11.115 cm and 7399±103.44 gr respectively, which were caught by local fishermen using fishing boats using two methods of fishing with hooks and gillnets, and until they reached the shore of Briss in Chabahar, they were in ice in some boats and in others they were kept frozen. After landing the fishes on the beach for qualitative evaluation, the studied samples were divided into 8 groups based on the type of fishing method (hook and gillnet) and the method of storage after catching (keeping in ice and freezing) on the float. The standard method of AOAC (2005) was used to measure the proximate compositions include moisture, crude protein, crude fat, and crude ash of the samples. The determination of the pH value was performed according to Chen et al. (2019). The determination of the TMA and TVB-N value was performed according to Li et al. (2019). Peroxide value was measured according to the iodometric method provided by Egan et al. (1979) through fish oil extraction using methanol-chloroform and anisidine index was performed according to the AOCS (1998) method with a standard number of 90-18 Cd based on the reaction between the anisidine reagent diluted in Glacial acetic acid with aldehydes in the fat sample.

In the present study, the results of the proximate composition in the muscles of Thunnus tonggol and Thunnus albacares fish species showed that the moisture content was above 70-75% in all groups of fish, except for the Thunnus tonggol fish caught with the hook method and kept in freezing condition. Usually, the largest percentage of biochemical compounds in the fish body is made up of water, which is less than 80% in medium-fat fish such as tuna (Amiri et al., 2015). Tuna fish have high protein (22.26-22.2 gr per 100 gr of muscle) and low fat content (0.2-2.70 gr per 100 gr of muscle) and high moisture content in fish with low fat content (Rani et al., 2016), that this was also observed in the present study. The amount of moisture and protein in Thunnus tonggol fish was slightly higher than Thunnus albacares fish. The difference in the proximate composition of fish may be due to feeding or fishing ground and season (Ali et al., 2020). In terms of fat content, Thunnus tonggol fish had more fat than Thunnus albacares fish, but the percentage of fat in both species was less than 5%. Usually, the amount of fat in tuna fish is less than 5% and they are classified as lean fish (Bahurmiz, 2019). The amount of ash was not much different in both types of Thunnus tonggol and Thunnus albacares fish, this issue shows the same nutritional value of Thunnus tonggol and Thunnus albacares fish in terms of minerals, because ash is a indices for measuring the mineral content of different foods, including fish. The amount of moisture, fat and protein in Thunnus tonggol fish caught with gillnet and kept in frozen state has decreased significantly compared to other fish groups (p<0.05), but there was no difference in the amount of ash between different groups of Thunnus tonggol fish (p>0.05). The reduction of protein in food products stored at freezing temperature can be caused by protein denaturation as a result of the increase of ionic bonds in the intracellular tissue, followed by the migration of water to the extracellular tissue.The reduction of fat during the storage period of fish may be due to the activity of enzymes involved in the hydrolytic spoilage of fat and its conversion into free fatty acids (Kusuma et al., 2017). In Thunnus albacares fish, except for the moisture, which was significantly reduced in the group of fish caught with gillnet and kept in frozen state compared to other groups (p<0.05), the amount of other proximate compounds did not differ significantly between different groups of fish (p>0.05) and the highest amount of these compounds was related to the group of Thunnus albacares fishes caught with hooks and kept in frozen condition. The measurement of chemical quality indicators showed that the pH level in Thunnus tonggol fish caught with gillnet and kept in ice increased significantly (p<0.05) and in Thunnus albacares fish caught with hooks and kept in freezing condition, decreased significantly (p<0.05). The decrease in pH indicates the phenomenon of glycolysis and as a result the production of lactic acid and its subsequent increase to a value higher than 7 also indicates the loss of quality due to the production of volatile compounds and the start of autolytic activity (Done et al., 2018). The peroxide value, thiobarbituric acid and TMA in the groups caught by the hook method and kept in the frozen state was significantly lower than the other groups, but the anisidine index did not show significant difference in all the fish samples (p>0.05). The amount of TVB-N in Thunnus tonggol fish had no significant difference and in Thunnus albacares fish it was 13.21 ± 1.53 mg/100g in the method of catching with gillnet and kept in ice, it was significantly higher than other groups (p<0.05). The amount of these compounds was lower than the acceptale limit (Jinadasa et al., 2015), which indicates the proper quality of the fish

Overall, the results of this study showed that fishes caught with hooks and kept in frozen condition have better nutritional value and quality than the other groups.

The present study was carried out with the aim of determining the biometric factors, length and weight relationship, frequency percentage of length and weight groups, and identification of food groups consumed in Alepes djedaba fish caught from the coast of Makkoran. For this purpose, 120 samples of Alepes djedaba were collected from the three catchment areas of Ramin, Haft Tir and Tis in Makkoran coast located in Sistan and Baluochistan province seasonally from autumn 2019 to summer 2020. The prepared fishes were caught by traditional fishing boats. After the fishes were prepared and transferred to the laboratory, the biometric characteristics, including the total length and body weight, were measured and the pattern of growth was determined. In the next step, in order to identify the food items, the contents of the digestive system were separated and identified. The results of the present study showed that the Alepes djedaba caught in the Makkoran coast in different seasons have different length and weight ranges. The average total length and weight of the fish were 28.00±4.68 cm and 311.18±12.00 gr, respectively. Based on the results, the value of b in the length-weight relationship to determine the growth pattern did not show a significant difference with the number 3 (p>0.05), which indicates isometric growth in this species. Food items identified in the stomach contents of this species included fish and crustaceans. According to the food items identified in the digestive system of the studied fish, it seems that this species is an advanced predator that is at the top of the food chain. Therefore, despite the differences in the composition of the population of food items in each environment, this fish feeds on a relatively constant diet including various types of fish and small crustaceans. From the obtained results, it can be stated that this species is carnivorous and its growth is isometric, and in different seasons of the year, different length and weight groups of this fish are caught in the Makkoran coast.

Brown, red, and green marine macroalgae marine macroalgae are rich sources of diverse bioactive components with valuable pharmaceutical and biomedical potentials that could be exploited as functional health-promoting ingredients in animal feeds. The objective of the study was to examine the effects of red seaweed Stoechospermum marginatum extract (SE) on fatty acid compositions and antioxidant status of grey mullet, Mugil cephalus, after 60 days. Four experimental diets were prepared: SE0 as a control treatment; SE5, SE10, and SE 15, which included 0, 5, 10, and 15 g SE kg-1 diet, respectively. One hundred twenty grey mullets weighing 9.56±1.02 g were randomly divided into four groups corresponding to the different feeding regimes. After 60 days of feeding, the results showed that the significantly lowest amount of myristic acid (14: 0) (1.06±0.09%) and stearic acid (0.08 C) (4.17±0.09%) was observed in treatment 4, whereas the amount of linolenic acid (C18:3n0-3, 2.52±0.03%) and linoleic acid (C18:2n-6, 42.69±2.09%) (60.60 09 2.09) of the PUFAs in treatment 4 were significantly higher than the control one (P<0.05). No significant differences were found in catalase (CAT) between the control group and treatments (P>0.05). The lowest level of Malondialdehyde (MDA) was shown in SE15. Treatments containing different levels of SE showed significantly different in superoxide dismutase (SOD and GSH compared with control treatment (P<0.05). The results of the experiment revealed that grey mullets fed SE15 diets showed improvement in the fatty acid composition and antioxidant status and the use of a diet containing 15 g/kg S. marginatum extract could suggest for grey mullet.

The aim of this study was to investigate the effects of sublethal concentrations of silver nitrate on changes in biomarkers of oxidative stress (superoxide dismutase, catalase, glutathione, total antioxidant capacity and malondialdehyde), in the hepatopancreas of white leg shrimp (Litopenaeus vannamei). For this purpose, whiteleg shrimp (Litopenaeus vannamei) post larvae shrimp were exposed to sublethal silver nitrate concentrations (equivalent to 10 % (treatment 1), 25 % (treatment 2), 50 % (treatment 3) and 75 % (treatment 4) LC50 AgNO3) for 21 days. Catalase, glutathione and total antioxidant capacity in treatments 3 and 4 compared to control treatment had a significant decrease while malondialdehyde increased significantly. Also, superoxide dismutase activity in both treatments 3 and 4, total antioxidant capacity decreased significantly only in treatment 4 compared to the control group, but malondialdehyde activity in treatment 4 increased significantly. The results of this study showed that exposure to concentrations of 0.042 and 0.063 mg/L of silver nitrate caused oxidative damage to hepatopancreas tissue of white leg shrimp (Litopenaeus vannamei).

Today, the continuous release of environmental pollutants into aquatic ecosystems has made these environments extremely vulnerable and turned them into a storage sites for these toxic substances, so it is necessary to investigate the effects of these pollutants on aquatic life. The present study was conducted with the aim of determining the toxicity of silver nitrate and observing the behavioral changes of Litopenaeus vannamei during its exposure. To determine the toxicity, the standard method of OECD was used. At first, the viability and survival of Litopenaeus vannamei were checked after two weeks of acclimatization to laboratory conditions, then by conducting preliminary tests, the actual lethality values ​​of silver nitrate were obtained. In order to determine the median lethal concentration, shrimps were exposed to concentrations of  0.025, 0.05, 0.1, 0.2, 0.4 and 0.8 mg/L of silver nitrate for 96 h and their mortality were recorded daily every 24 h. The LC50, LOEC, NOEC and MATC were calculated based on shrimp mortality. During the viability and survival test, no mortality were observed up to 96 hours, and the survival rate of shrimps was 100%. The value of LC50, NOEC, LOEC and MATC were determined as 0.084, 0.02, 0.025 and 0.0084 mg/liter, respectively. In different concentrations of silver nitrate, shrimps showed behaviors such as abnormal swimming, fast movements of swimming legs, coming to the surface of the water, twisting the body around itself and eventually losing balance.

After catching fish, various changes occur in the fish body and as a result of these changes the quality of the fish gradually decreases. This reduction in quality in fish is due to the growth and invasion of bacteria, autolysis process, lipid oxidation, physical and mechanical damage, that affects the freshness of the fish. Since freshness is one of the most important parameters in the fish market for the consumer, so the present study was conducted with the aim of evaluating the freshness and quality of fish sold to the Chabahar fish market by using a combination of sensory, chemical and microbiological methods.

In order to evaluate the freshness and quality, 30 fish belonging to 10 species including yellowfin sea bream (Acanthopagrus latus), frigate tuna (Auxis thazard), largemouth queenfish (Scomberoides commersonnianus), Indian mackerel (Rastrelliger kanagurta), shrimp scad (Alepes djedbada), tigertooth croaker (Otolithes ruber), pickhandle barracuda (Sphyraena jello), golden snapper (Lutjanus johnii), javelin grunter (Pomadasys kaakan) and goldstripe sardinella (Sardinella gibbosa) were purchased from Chabahar fish market and immediately transferred to the laboratory after icing. The quality of the studied fish was evaluated using sensory, biochemical (TVN, TMA, TBA and pH) and microbial (mesophilic and psychrophilic) methods.

According to the results, in terms of sensory evaluation, no statistically significant difference was observed between different fishes (p>0.05), but the highest scores of sensory factors were related to tigertooth croaker (Otolithes ruber) and pickhandle barracuda (Sphyraena jello) and the lowest It was related to goldstripe sardinella (Sardinella gibbosa). The results of biochemical evaluation showed that, except for pH, the highest amount of these indicators is related to Auxis thazard and Sardinella gibbosa, and there was a significant difference in the amount of TVN, TMA and TBA with other fish species (p<0.05). The bacterial counts in all samples was less than the permissible limit, but in Auxis thazard and Sardinella gibbosa, the number of mesophilic bacterial load was significantly higher than other fish (p<0.05), as well as the Also, the lowest and highest psychrophilic bacterial load was related to Otolithes ruber and Auxis thazard, which were significantly different from each other (p<0.05).

Overall, the results of this study showed that the fish sold in the Chabahar fish market are of suitable and acceptable quality, and fatty fish such as sardines are more susceptible to spoilage than low fat fish because in this species TMA with a rate of 7.48 ± 1.00 mg/100 g reached the permissible level of spoilage.

Exposure of aquatic animals to silver, due to production of free radicals, causes oxidative damage and biochemical changes in organisms. Therefore, in present study, changes in the antioxidant defense system and metabolic indices of Litopenaeus vannamei were evaluated during 21 days of exposure to silver nitrate. Shrimps exposed to different concentrations of silver nitrate, including treatment 1: 10% LC50 (0.0084 mg/L), treatment 2: 25% LC50 (0.021 mg/L), treatment 3: 50% LC50 (0.042 mg/L) and treatment 4: 75% LC50 (0.063 mg/L) and one treatment as control treatment. Superoxide dismutase activity in treatments 3 and 4 and total antioxidant capacity in treatment 4 was significantly reduced (P<0.05). But malondialdehyde activity was significantly increased in treatment 4 (P<0.05). Catalase and glutathione activity in all treatments did not show a significant difference (P>0.05). Among metabolic indices, only in treatment 4 protein changes were significantly reduced, and glucose, cholesterol and triglyceride were significantly increased (P<0.05). But the amount of phosphorus and calcium did not show a statistically significant difference (P>0.05). In general, exposure to 75% LC50 of silver nitrate with a significant decrease in the activity of antioxidant enzymes and an increase in malondialdehyde caused oxidative damage and disruption of some metabolic parameters of Litopenaeus vannamei.

Oxidative stress is believed to be one of the major causes of tissue damage in aquatic animals exposed to heavy metals. It leads to certain changes in the antioxidant and enzyme system. Given the fact that research on the effect of sub-acute toxicity of silver nitrate in shrimps is not very developed, the present study can be conducive to formulating the international standards of contamination of shrimps with silver nitrate.

The present study aimed to evaluate the toxic effects of silver nitrate on the changes in the antioxidant and enzyme systems of hepatopancreas, muscle and gills of Litopenaeus vannamei.

After acclimatization of shrimps, they were exposed to silver nitrate with concentrations of 0.0084, 0.021, 0.042 and 0.063 mg/L for 21 days. At the end of the experimental period, gill, muscle and hepatopancreas were sampled, and the changes in the antioxidant system (SOD, GPx and GST) and metabolic enzymes (ALT, ALP, AST and LDH) were examined.

There was no significant difference in terms of SOD and GST activity in the gill and muscle of the exposed shrimps (P>0.05). However, GPx in treatment 4 increased significantly in gill and muscle while it saw a decrease in hepatopancreas (P<0.05). In hepatopancreas, GST significantly increased in treatments 3 and 4 (P<0.05) whereas SOD did not show any significant changes compared with other treatments (P>0.05). The metabolic enzymes of the muscle did not show any significant differences in any of the treatments (P>0.05), but in gill, the level of ALT in treatment 4 decreased significantly while the levels of AST and LDH in treatment 3 and 4 significantly increased (P<0.05). In hepatopancreas, the activity of ALT in treatments 2 and 4, AST in treatments 3 and 4, and ALP in all treatment except treatment 1 saw significant reduction. Nevertheless, LDH in treatments 3 and 4 had a significant rise (P<0.05).

A significant increase in GST and LDH as well as a significant decrease in GPx and ALT, AST and ALP enzymes in the hepatopancreas revealed that the antioxidant and enzyme system of shrimps is further disturbed with the rise in silver nitrate concentration in the hepatopancreas compared to the gill and muscle.

Monitoring and tracing of heavy metals is necessary to compare with existing standards, regarding the input of various pollutant sources, including heavy metals into water resources and eventually accumulation in aquatic organisms. Lead and Cadmium in the fish of various sources of water supply (springs, rivers, wells, rivers and sea cages) in the east and west of the province. After drying and digestion of muscle samples in acidic solutions, the amount of lead and cadmium heavy metals was read using standard atomic absorption spectrometers in different lamps. A study on the mean amount of lead in different fields of salmon farming on the basis of water supply source showed that the amount of lead in the fish muscle of farmed farms with a source of water was much higher than other areas (967 mg/l) and farms in the cage the lowest 0.013 mg/l. The average of total fish lead in the province was 279 mg/kg, which is lower than the national and international standards. The amount of lead in the water supply sources of the studied farms was less than the virtual limit referred to in various sources. In the case of cadmium, the amounts in water and muscle were also negligible and were outside the detection range of the atomic absorption system, which indicates the health of water and fish in terms of cadmium. Comparison of heavy metal concentrations in Golestan province with other parts of the country showed that this amount was the lowest reported in the country, which indicates the health of Golestan province. Also, comparing the levels of Pb and Cd in salmon in the cages of Golestan province with similar values to other fish in the Golestan province showed that the amount of trout heavy metals was much lower and had a better health. The levels of lead and cadmium in water and fish was lower than all national and international standards and were below the maximum authorized limit, so no risk to these end-users is noticed by the final consumer.

Increasing the use of nanomaterials leads to the release of these particles in aquatic environments that can have effects on aquatic animals, therefore, the present study aimed to investigate the toxicity of titanium dioxide nanoparticles produced by the Chemical and biological method on Xiphophorus maculatus. First, the survival rate of fish under similar conditions to toxicity experiments were investigated  and then Xiphophorus maculatus fish to determine the intermediate lethal concentration (LC50) of nanoparticles in 12 treatments (each with three replications) including 6 treatments containing concentrations of 0, 80, 160, 320, 640 and 1280 mg /L nanoparticles titanium oxide produced chemically and 6 treatments containing concentrations of 0, 240, 480, 960, 1920 and 3840 mg /L titanium dioxide produced biologically method in 60 liter tanks with 15 fish per treatment were exposed for 96 h and fish mortality were recorded at 24, 48, 72 and 96 h. Survival tests showed that up to 96 hours after stocking fish, no mortality were observed and the survival rate was 100%. With increasing the concentration of nanoparticles and increasing the exposure time, the percentage of fish mortality increased. The intermediate lethal concentrations (LC50) of titanium dioxide nanoparticles produced by chemical and biological methods during 96 h of exposure were 255.49 and 720.76 mg/l, respectively. Based on the results of the present study, chemically produced nanoparticles are more toxic than nanoparticles produced biologically method.

In present study, the effect of different thawing methods on the quality of Otoithes ruber was studied. For this purpose, freshly caught fish were transferred to Chabahar Pasabandar fish processing plant. After transfer, they were frozen at -36 ° C and stored in a cold storage at -18 ° C for four months. After that, the chemical (pH, trimethylamine, thiobarbiotic acid and volatile nitrogen bases), physical (water loss, water loss after cooking) and microbial (mesophilic and psychrophilic) indices during thawing methods by water, air, refrigerator and microwave were examined. According to the results, the amount of volatile nitrogen bases and thiobarbiotic acid in all methods of thawing showed a significant difference with the control group (p <0.05) and the highest amount was related to thawing by microwave method. The lowest amount of trimethylamine was observed by refrigeration thawing method and there was a significant difference between different treatments with each other and also in the control group (p <0.05). The pH of different thawing methods increased significantly compared to the control group (p <0.05). The highest amount of water loss and water loss after cooking was observed in microwave thawing, which had a significant difference with other treatments (p <0.05). The number of mesophilic bacteria during different methods of thawing except for thawing method by air was significantly reduced compared to the control group (p <0.05) and the lowest amount of mesophilic bacterial load was observed in microwave thawing method. Psychrophilic bacteria load was significantly increased compared to other methods during refrigeration thawing method (p <0.05).

Due to the effects of seaweeds on defense mechanism and improving the oxidant/antioxidant status, extracts of Cystoseira indica on some oxidative stress index of common carp (Cyprinus carpio) gill tissue by adding to the rearing water environment during three weeks culture was evaluated. The extract was added in three different levels of 1%, 5% and 10% Cystoseira indica algae per liter of rearing water. Storage of fish were stocked at a density of 5 fish in each 10-liter of aquarium. The experiments were set up in three treatments containing Cystoseira indica extract and a control group (each with three replicates). Sampling of fish was conducted to measure oxidative stress index on days 7, 14 and 21. According to the results, the highest survival rate, specific growth rate and the lowest feed conversion ratio were observed in 10% of algae extract. Superoxide dismutase and catalase activity in the treatment of 10% algae extract compared to control treatment significantly increased and activity levels of malondialdehyde was significantly reduced. The level of glutathione peroxidase activity in different treatments Seaweed was no significant difference with control treatment. The results of the present study showed that adding 10% of algae extract to the rearing medium of common carp improves the growth indices as well as enhances antioxidant defense system by increasing the of antioxidant enzymes activity

In the present study, whiteleg shrimp postlarvae were exposed for 21 days with sublethal concentrations of silver nanoparticles containing treatment 1: (%10 LC50 (0.39 mg/L AgNP), treatment 2: (%25 LC50 (0.97 mg/L AgNP), Treatment 3: (%50 LC50 (1.95 mg/L AgNP)and treatment 4: (%75 LC50 (2.92 mg/L AgNP) and one treatment was considerd as control treatment. during 21 days. At the end of the experiment, gill, muscle and hepatopancreas tissue samples were samples to measure changes in levels of metabolic and antioxidant enzymes. According to the results, the enzyme activity of alanine aminotransferase and aspartate aminotransferase in hepatopancreas and gills showed a significant increase compared to the control (p<0.05), but there was no significant difference in muscle (p>0.05). Alkaline phosphatase activity was only decreasing in hepatopancreas, which was significantly higher than control (p<0.05). Lactate dehydrogenase level was not significantly different in all tissues (p>0.05). Among the antioxidant enzymes, the activity of superoxide dismutase in hepatopancreas and gills showed a significant decrease (p<0.05) compared to control, but glutathione peroxidase had no significant difference (p>0.05). The level of glutathione S-transferase was increased only in hepatoconal tissue and in treatment 4 significantly (p<0.05). The level of glutathione S-transferase was increased only in hepatopancreas tissue and in treatment 4 significantly (p<0.05). Overall, results showed that shrimp exposure to high concentrations of silver nanoparticles causes oxidative damage, especially in the hepatopancrease tissue.

Recently, the use of synthetic antioxidants has been limited due to having chemical and toxic compounds, so the use of natural compounds such as algae, as an alternative to synthetic compounds, is important for the storage of fishery products. The aim of this study was to investigate the effect of Padina australis alga extract on controlling the oxidative spoilage of muscle of  Epinephelus coioides during refrigerated storage.

Extraction of algae was performed using methanol. The fish were immersed in four different levels of the extract including 0 (control), 150, 300 and 600 mg/L, and were immediately stored in refrigerated polyethylene bags for 12 days. Sampling was carried out on days 0, 3, 6, 9 and 12 to measure lipid oxidative indices.

The results showed that the amount of peroxide, thiobarbituric acid, anisidine and Totox value at 300 and 600 mg/l levels of algae extract decreased significantly from day 9 comparing to the control treatment (p <0.05). There was no significant difference between the conjugated diens’ indices in different treatments and days (p> 0.05). The amount of free fatty acids only decreased in the 600 mg/L treatment comparing to the control treatment (p <0.05).

Algae extract at 600 mg/L concentration had high antioxidant effect; in this concentration, oxidative degradation indicators were in the standard range until the end of the storage, so it can be used as an alternative to synthetic compounds in food.

In recent years, the use of dietary supplements, especially synbiotics, in the diet of farmed fish has been considered due to its beneficial effects on fish health. In this study, the effects of different levels of symbiotic Biomin Imbo were examined on the antioxidant activities, digestive and bacterial flora in the intestine of Mugil cephalus</em>. One hundred and twenty grey mullet with a mean weight of 3.92 ± 0.43 g were reared in 60-liter aquaria for 60 days (10 fish in each aquarium) and the treatments were fed with diet containing symbiotic supplement at different levels including 0.5 (T0.5</sub>) , 1 (T1</sub>), 1.5 g (T1.5</sub>) synbiotic per kg of feed, while control contained no supplementation. Feeding was carried out manually. At the end of the experiment, the fish intestine was removed and antioxidant enzyme activities including superoxide dismutase, glutathione peroxidase and glutathione S-transferase as well as digestive enzyme levels including lipase, amylase, alkaline phosphatase, protease, pepsin, chymotrypsin along with microbial flora were assayed. According to the results, superoxide dismutase activity at T1</sub> and T1.5</sub> and glutathione S-transferase and glutathione reductase at T1</sub> were significantly increased compared to the control (p<0.05), whereas glutathione peroxidase activity did not exhibit any significant difference (p>0.05). The high levels of synbiotic displayed significant effects on all the digestive enzyme activities except for alkaline phosphatase and lipase (p<0.05). Total number of viable and lactic acid bacteria in T1</sub> and T1.5</sub> significantly increased compared to the control, while the number of coliforms in these treatments was significantly decreased (p<0.05). The findings of the present study exhibited that the diet containing 1 g synbiotic per kg of feed can be used as a suitable dietary supplement for grey mullet.

 In this study, in order to investigate the antibacterial properties of silver nanoparticles that were synthesized using Sargassum seaweed extract by biological extracellular method, Mesophile Enterobacteriaceae, lactic acid bacteria and psychrophilic bacteria skin of common carp exposed to three concentration (0.11, 1.13, 5.67 mg/L AgNP) of this silver nanoparticles were studied for 14 days. The results showed that with increasing concentration of silver nanoparticles, the load of Enterobacteriaceae and Mesophile significantly reduced compared with control (p0.05). The lowest bacterial count was related to enterobacteria (log cfu/cm2 1.00±0.01), when exposed to concentration 1.13 mg/L AgNP. Lactic acid bacteria in all treatments and in control, did not grow until the last day of exposure.

In this study, gelatin from common carp scales (Cyprinus carpio) was produced using alkaline, acidic and thermal methods. Then, the physical factors, barrier properties and its appearance characteristics were optimized by changing effective factors in the initial gelatin extraction process. In order to optimize the film, the response surface methodology included a central composite design for extraction process, a series of effective factors in extraction including sodium hydroxide concentration, alkaline pre-treatment, hydrochloric acid concentration and extraction temperature as independent variables were investigated. The dependent variables including tensile properties, water solubility and water vapor permeability were investigated. The results of screening based on mechanical strength and solubility resulted in the selection of 4 factors of 9 factors. In the screening stage, four variables including two factor of the pH of extraction and the duration of the alkaline treatment that had the greatest effect on the tensile strength, and two factor including concentrations of acid treatments and the extraction temperature that had the most effect on the solubility of the films were selected for the the main experiments with gelatin extraction. Other variables that did not have a significant impact on the mechanical properties and film solubility were in their most common form. The main experiments of gelatin extraction included 30 treatments. Solubility showed significant changes (p <0.05). The lowest solubility was 25.08% for treatment No. 9 with alkaline treatment for 195 minutes, acid treatment with 0.3 molar concentration and extraction at 63 ° C. The lowest permeability was for treatment No. 15 with alkaline treatment for 140 minutes, acidic treatment with a concentration of 0.18 molar and extraction at 76 ° C (p <0.05). Finally, it was determined that by changing some of the extraction factors, the properties of gelatin film obtained from common carp scales could be optimized.

The consumption of probiotics in aquaculture is constantly growing due to the numerous benefits conferred on the fish health. Degradation of probiotics in gastrointestinal tract is one of the most important challenges in probiotic efficacy. Encapsulating of probiotics within a physical barrier has been found to increase probiotic viability in fish gastrointestinal tract. In this study the effect of encapsulation of Lactobacillus plantarum with alginate/chitosan nano particles in in vitro situation and their effects in Huso huso were evaluated. Firstly, in vitro probiotic potential including: pH and bile resistance, gastrointestinal juice tolerance was evaluated. Then effects of encapsulated probiotic were evaluated in Huso huso. 480 juvenile H. huso were randomly divided into four treatments in triplicates. Fish in T1 were fed with alginate/chitosan enriched free probiotic diet, T2 received encapsulated Lactobacillus plantarum, T3 received bacteria without any encapsulation and T4 received basic diet as a control group. All treatments were fed with experimental diets for 60 days and study lasted for 15 days with control diet in all fish. Fish samples were taken on days 30, 60 and 75 and bio chemically compared among the treatments. Results of first phase of study showed that mostly all probiotic properties of encapsulated bacteria were more appropriate than control treatment (P<0.05). Encapsulation of bacteria in both procedures enhanced almost all immunological parameters compared to control treatment (P<0.05). Higher Ca and Mg of plasma were observed in fish fed with Lactobacillus plantarum nano/microencapsulated and alginate/chitosan at day 30 and 60, whereas decreased TRI of plasma was observed in fish fed with Lactobacillus plantarum nano/microencapsulated at day 30. It can be concluded that nano encapsulation of Lactobacillus plantarum with alginate/chitosan not only improved in vitro probiotic effects of L. plantarum, but also it can increase Biochemical parameters of H. huso and could improve the positive performance of probiotics activity.

This experiment was conducted to evaluate the effect of different levels of supplementation of algae Sargassum ilicifolium on the growth performances, feed indices, body composition and digestive enzymatic activities of grey mullet (Mugil cephalus) for 60 days. The experiment was conducted in a completely randomized design with 120 of grey mullet (with average weight of 11.77±1.07g) divided in 4 treatments and 3 replicates (n=10 in each replicate) and included: 0, 5, 10 and 15 g algal extract per Kg diet. The results showed that at the end of experiment, the highest final weight (FW), specific growth ratio (SGR) and protein efficiency rate (PER) were observed in treatment 4 (15g/Kg). The highest crude protein, moisture and amylase, lipase, protease activities the lowest crude lipid were observed in treatment 4. However no significant difference were observed in amylase activity, between 10 and 15g extract per Kg diet (P>0.05). Overall, the results of the experiment revealed that grey mullet fed with 15g S. ilicifolium per Kg diet showed better growth performance, feed utilization, body composition and digestive enzymatic activities than control group, and could suggest for grey mullet.

In this study, effects of Persian gum-chitosan and Persian gum-chitosan incorporated with Garlic (Allium sativum L.) essential oil edible coatings on change in chemical deterioration index (peroxide value (PV), free fatty acids (FFA), thiobarbituric acid index (TBA) and total volatile basic nitrogen (TVB-N)) and sensory properties (Taste, appearance, color, odor and overall acceptability) during 6 months frozen storage (-18 ºC) was investigated. Silver carp fillets were immersed in the Persian gum-chitosan and Persian gum-chitosan incorporated with Garlic essential oil (5%) solutions and then packed and frozen. Experiments were carried out at months 0, 2, 4 and 6 of storage on frozen fillets. Comparing to control, lipid oxidation was significantly delayed in samples treated with Persian gum-chitosan and Persian gum-chitosan incorporated with Garlic essential oil (P ≤0.05). According to the results, application of Persian gum-chitosan incorporated with Garlic essential oil gave the best antioxidative activities and sensory scores. Keywords: Persian gum, chitosan, Allium sativum, silver carp

Biogenic amines are nitrogen-based organic compounds, which are basically produced by decarboxylation of amino acids. The presence of high amounts of biogenic amines in food represents deterioration and undesirable quality of food. In this study, changes in the amount of biogenic amines produced in the muscle of the croaker (Otolithes rubber) as a chemical indicator of spoilage caused by different methods of thawing (water, air, refrigerator and microwave) were evaluated. The croaker fishes were kept in powdered ice and transported to the processing factory, where they were deep frozen at -36°C through a freezing tunnel, followed by storage in cold store at -18°C for 4 months. The experiments were conducted by application of different thawing methods of water, air, refrigerator and microwave, followed by simultaneous monitoring of changes in the biogenic amines (histamine, putrescine, tyramine and cadaverine). The results showed a significant decrease in the amount of histamine during thawing in refrigerator compared to the other methods and control (P<0.05). Also, a significant decrease was observed in the amount of putrescine produced during thawing by microwave technique compared to the other methods (P<0.05), but there were no significant differences between the amounts of tyramine and cadaverine produced by different thawing methods compared to the control treatment (P<0.05). The highest levels of histamine and putrescine were observed in thawing methods of air and refrigerator respectively. Based on the results of this study, it can be concluded that thawing by refrigerator method can be suitable technique for defrosting the frozen croaker fish.