فصلنامه شیلات
سال هفتاد و چهارم شماره 3 (پاییز 1400)

Global human population growth, changes in lifestyle and food consumption patterns have led to an increase in demand for marine source foods production. Proper use of all produced seafood sources, in addition to increasing the production efficiency, provides nutrients and sustainable human nutrition. Bone lesions yielded from aquatic processing are rich sources of essential protein and minerals, which are mainly not intended for direct human consumption. Therefore, in order to make the best use of these valuable wastes, at the present study, for the optimal use of these valuable lesions, bone lesions of yellowfin tuna as the raw material for tuna processing factories has been used. In order to achieve the best drying method, three drying methods were considered: drying in the open air, drying in the hot air oven and drying in a freeze dryer. After providing the above-mentioned bone powders, the amount of their nutrients including crude protein, total fat, ash, moisture and main mineral elements (calcium, phosphorus and magnesium) were measured. The results showed that the amount of protein (31.03%) and ash (49.53%) of bone-dried powder by freeze drying method had a significant difference compared to other two methods (P<0.05) and It retains more nutrients in all cases. The moisture content of this treatment was 2.55% which was less than other treatments and there showed a significant difference compared to other methods (P<0.05, indicating a better drying process of bones by freeze drying method. Examination of the amount of calcium and magnesium in the freeze-dried treatment also shows higher and significant amounts of these two elements than the other two methods, however it had negative trend to rate of moisture. Therefore, method of freeze drying, was known as the shortest time for drying the fish bone and conserving its biochemical and nutrients

Deficiency of micronutrients in the diet and their impacts on human health, is an emerging issue in the world. Therefore, fortification of human’s diet could be viable solution to this issue. In this study, silver carp’s bone powder (SCBP) at different levels (0, 2, 4 and 6%; w/w) were used for partial replacement of wheat flour in the cake. Results showed that incorporation of SCBP in the cake, increased the content of Cu, K, Mg, Mn and Zn (P<0.05) in the cake. The content of Cu, K, Mg, Mn and Zn in the treatment with 6% replacement was 3.07, 104, 4.72, 41.08 and 2.14 mg 100 g-1 cake, respectively. However, the content of Fe and Na was reduced, and their contents were reported as 113.46 and 1.30 mg 100 g-1 cake, respectively in the same treatment. These reductions were significantly different compared to control treatment. According to the results, replacement of wheat flour with 6% SCBP is recommended to use in the cake. Thus, this fortified cake could be a logical vehicle of nutrients for preschool children and adolescents.

In this study, sturgeon species were identified based on mitochondrial genome amplification (D loop control region) and band size differences by agarose gel. For this purpose, a total of 140 Caspian Sea sturgeons and Siberian sturgeons were selected. After DNA extraction, primers were used to amplify the D-loop control region. The right primers were the same in all species but the left primers were different and they were selected such that the size of different species was distinct. Based on the obtained results, the desired bands for all species of Caspian Sea sturgeon and Siberian sturgeon, except Beluga, were amplified which represents the species for that sample. This method is a useful approach for detection of fraudulent mislabeling of the fishery products including sturgeon and caviar due to its ease and rapid execution. However, since the mitochondrial genome has only maternal inheritance, for additional tracking, the whole genome of sturgeon should be studied for each species in order to obtain the desired points for tracking the differences of Caspian Sea sturgeon at the nuclear genome level, thereby a diagnostic evaluation as well as barcoding of samples of fishery, health and cosmetic products from Caspian sturgeon can be done by combining differences at the mitochondrial and nuclear genome levels of the species. of the species.

Astaxanthin pigment is one of the most important carotenoids in terms of antioxidant properties, and an important micronutrient in the aquatics diet due to desirable effect on antioxidant activity, immunity functions, and feed efficiency. This study was conducted to evaluate the effects of astaxanthin pigment on antioxidant activity, and digestive enzymes of the oriental river prawn (Macrobrachium nipponense). In the present experiment, two hundred and twenty-five prawns with mean weight of 1.40±0.05 g were fed by five formulated diets containing different astaxanthin levels, zero (control), 50, 100, 150 and 200 mg per kg for 56 days. At the end of the culture period, the hepatopancreas, and intestine samples of the studied prawns were collected then antioxidant parameters, and digestive enzymes of the samples were evaluated by experimental kits, and spectrophotometric method. The results of the study showed that total antioxidant capacity increased significantly compared to control treatment, while superoxide dismutase, catalase, and malondialdehyde decreased significantly in diets containing astaxanthin treatments (p < 0.05). However, the antioxidant activity of glutathione peroxidase was not affected by different dietary astaxanthin levels (P>0.05). Digestive enzymes were affected by different astaxanthin levels, and with increasing dietary astaxanthin, digestive enzymes increased significantly (p < 0.05). Finally, the results of this study showed that increasing dietary astaxanthin levels improved the activity of antioxidant parameters, and digestive enzymes of the oriental river prawn, and suggests that diet containing 150 mg/kg of this pigment to improve the mentioned parameters of this prawn. n.

Fish Fillets are perishable due to their poly unsaturated fatty acids and the use of natural antioxidants during storage is of interest to researchers. The aim of this study was to investigate the effect of hydrolyzed protein produced from the viscera of common carp on the shelf life and quality of carp fillets at refrigerator (4±1°C). For this purpose, the common carp viscera were hydrolyzed with alkalase enzyme (concentration 1%, temperature 55 ° C and pH 8) during different times of 30, 60, 120 and 180 minutes and IC50 of hydrolyzed protein (after 180 minutes of hydrolysis) in the DPPH inhibition was obtained 1.34 ± 0.01 mg/ml and the IC50 of vitamin C was determined to be 13.78±0.6 μg/ml. Then, to investigate the effect of hydrolyzed protein on the shelf life of fillets, experimental treatments including fillets with hydrolyzed protein coating, fillets with vitamin C coating and control (without coating) were prepared, and then, chemical parameters (pH, TBA and TVB-N) and microbial (TVC and PTC) parameters were measured in carp fillets kept at 4±1 °C on days 0, 4, 8, 12, 16 and 20. During the storage period, TBA, TVB-N, TVC and PTC had an increasing trend in all treatments, but the level of these indices in the control treatment was significantly higher than those treated by hydrolyzed protein and vitamin C (p<0.05). Overall, comparison of hydrolyzed protein and vitamin C showed that in all studied indices (except TVB-N on some days of storage), the function of hydrolyzed protein in IC50 was similar to vitamin C and can be suggested as an antioxidant to increase shelflife of fish fillet at refrigerator.

The present study was performed to determine the effects of resveratrol as a natural polyphenol on growth and nutrition indices of zebrafish (Danio rerio). Resveratrol was performed over a period of 60 days on 120 adult zebrafish with approximate weight of 2 ± 0.3 g and length of 3 ± 0.5 cm, which were randomly divided into 2 main groups, each of which consisted of 4 subgroups (a total of 8 Treatment) were divided as follows: The two main groups under the influence of added glucose in aquarium water (+ G) and without glucose (-G) and each of these two groups into 4 subgroups (control = CTRL) , (resveratrol = RSV ) With doses of 20, 10 and 30 micromole per liter. Fish were randomly distributed in 5 pieces into 24 tanks (3 treatment in 3 replicant) with a water volume of 3 liters. At the end of the period, weight gain, feed conversion ratio, protein efficiency ratio, specific growth rate and body growth index and enzymes of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkannin phosphatase (ALP) were evaluated. According to the results, the highest feed conversion ratio belonged to the resveratrol 20 group under the influence of glucose (G + RSV30). The highest rate of protein efficiency ratio, specific growth rate and body weight gain belonged to the glucose-free control group and no significant difference was observed between treatments. Also, the treatment of resveratrol 20 group without glucose (G-RSV20) had the lowest amount of enzyme (ALP) and no significant difference was observed with other groups and the treatment of control group without glucose (G-CTRL) had the lowest amount of enzymes (AST) and (ALT) and a significant difference was observed with other groups (p <0.05). The results of this study indicate that resveratrol did not have a positive effect on growth indices and AST and ALT enzymes but improved ALP enzyme function.

Sexual dimorphim in morphometric characters and some growth parameters of the Arabian carpetshark, Chiloscyllium arabicum was investigated from 381 collected samples (190 males and 191 females) to aim for stock assessments of this population in Persian Gulf for first time. Total length range was estimated 37.7-70.5 cm (mean of 58.93±6.44 cm) for males and 37.9-75.6 cm (mean of 59.49±8.24 cm) for females. First dorsal fin height was obtained higher in female (p < 0.05). Also, all of morphometric parameters except pre-caudal fin length, pre-second dorsal fin length, pre pelvic-fin length were more for female sharks (P>0.05). Male and female sharks showed negative and positive allometric growth respectively. Also, the b value of females (3.23) was more than of male (2.93) (p < 0.05). Asymptotic length (L∞), growth rate (k) and t0 of males were 75.9 cm, 0.93 per year and -0.8; those for females were 75.85 cm, 0.94 per year and -0.79 years respectively. The results derived of this study can useful for determining strategies for further conservation and management policies aimed to preserve the biodiversity of C. arabicum.

One of the most important problems in using probiotics in the aquaculture industry is their high mortality rate due to selection of processing conditions before using, storage methods and their adaptation in digestive ducts of aquatic animals. The newest methods to protect and increase the stability of probiotics in intestinal aquatic animal ducts is microencapsulation method. Microencapsulation keep the quality of the probiotics due to production processes, unfavorable gastrointestinal conditions, and environmental storage conditions. In this study, the first Lactobacillus rhamnosus as a probiotic coated with sodium alginate and chitosan, then the viability and potency in tolerating bile pH and stomach simulated conditions in rainbow trout (Oncorhynchu smykiss) were evaluated. After that, microencapsulated probiotics were added to the food pellets by spraying method and were given to rainbow trout juveniles with an average initial weight of 6.23 ± 0.17 g for a period of 60 days. At the end of the experiment, the results showed that the microencapsulated probiotics were more resistant to the stomach simulated conditions in rainbow trout in comparison with the free probiotics treatment as control. Also, the results showed that the growth indices in the treatment, the fish fed feed containing the sodium alginate-chitosan -microencapsulated probiotics had average daily weight gain 0.48 g, weight gain 28.8 ± 0.63 g and weight gain percentage 468.37 ± 16.63% and more efficient than the control treatment (P<0.05).

In the present study, the effect of alcoholic essential oil of Mentha piperita at concentrations of 0, 0.5 and 1% and at 4, -3 and -10 °C on the shelf-life of Litopenaeus vannamei during 15 days of storage, using by response surface method was analyzes. Essential oil analysis using GC-MS showed the menthol as the most abundant compound in essential oil. About total viable count (TVC), the total volatile nitrogen bases (TVB-N), peroxide value (PV), thiobarbituric acid (TBA) and free fatty acid (FFA) concentration of essential oil, with high level of F-value compared to time and temperature, was the most important factor affecting the shelf life of shrimp (p < 0.05). Shrimp kept at -10°C on the 7 and 15th days of storage at 0.5 and 1% concentrations, respectively, were within the allowable range for human consumption. Based on the results, TVC and then TVB-N were the most important factors in determining the shelf life of shrimp. The regression coefficient (R2, R2-adj) showed that, the regression model was able to describe the relationships between the various variables of time, temperature and essential oil concentration and the dependent variables and the obtained models predicted near-realistic values that could be they used it as a way to reduce the cost of testing.

The use of pesticides has always been associated with environmental concerns. Vista is a new and widely used pesticide in rice fields for blast disease. The present study investigated the lethal range and median lethal concentration of Vista fungicide in Ctenopharyngodon idella, for the first time. In this study, to determine the lethal range fish were first exposed to the concentrations of 0,10, 25, 50, 100, 250 and 500 mg per liter of Vista, and fish mortality were recorded in each group for 24, 48, 72 and 96 hours. Then, in order to determine median lethal concentration, fishes in 5 groups received concentrations of 0, 30, 35, 40 and 45 mg per liter Vista with three replication, and the number of fish mortality was recorded at 24, 48, 72 and 96 hours. The results were evaluated by probit statistical analysis. In this study, the median lethal concentration of Vista were 60.5, 40.1, 34.58 and 31.28 mg per liter at 24, 48, 72 and 96 hours, respectively. The Maximum Allowable Toxicant Concentration of Vista fungicide was 3.128 mg per liter, and its Lowest Observed Effect Concentration was estimated to be 28.42 mg per liter. The results of this study showed that the lethal concentration of Vista fungicide decreased with increasing test time, so that as the test time increased, a lower concentration of Vista fungicide caused fish mortality.

Microalgae are a very diverse group of aquatic plants that have numerous applications in biotechnology today. These microscopic photosynthesizers, have an extensive role in producing oxygen on Earth, they are found in almost all water sources on Earth due to their high dispersion and abundance. In this study, to investigate the effect of carbon sources on biochemical compounds such as proteins, carbohydrates and antioxidants, sources of organic carbon like glucose and glycerol were used. The results showed that most carbohydrates production was in a sample with 3 g / liter of glucose plus 5 g / Liters of glycerol in Monoraphidium and the lowest amount in the control sample of Scenedesmus. The lowest amount of protein was in the sample contains 1 g / liter of glucose in Scenedesmus and the highest amount in the control sample of Monoraphidium. The amount of antioxidants calculated by FRAP, and it was the highest in the control sample of Monoraphidium and the lowest recorded in the sample containing 3 g / liter of glucose in Monoraphidium. The results of this study indicated that the use organic carbon sources such as a combination of glucose and glycerol stimulates the production of carbohydrates but reduces the production of proteins and antioxidants.

This study aimed to investigate the effect of reduction of feeding rates on water quality, growth performance, and immune response in bio-floc common carp (Cyprinus carpio) and clean water systems. Fish (9.04 ± 0.44 g mean initial weight) were stocked into 18 tanks (50 L) through a 2×3 factorial design consisting: The use of commercial feed of 100, 85 and 70% (2.5, 2.12 and 1.75 % of body weight) in bio-floc groups (BF1, BF2 and BF3) and non-floc groups (NF1, NF2 and NF3) for 60 days. At the end of the experiment, Total ammonia nitrogen (TAN) concentration was significantly lower in bio-floc compared to non-floc. The highest fish growth performance and the lowest feed conversion ratio were obtained in the bio-floc groups with 2.5 and 2.12% feed intake (BF1 and BF2), respectively. After 60 days, the serum lysozyme and total immunoglobulin levels were significantly increased and serum cortisol levels decreased in the bio-floc groups. This study showed that reducing the feeding rates (2.12 to 2.5% of body weight) have a positive effect on growth performance and immune response in bio-floc common carp culture system compared to clean water system.