مجله علمی شیلات ایران
سال سی‌ام شماره 1 (پیاپی 123، فروردین و اردیبهشت 1400)

This study was performed to measure the amounts of heavy metals lead, nickel, zinc, iron and copper in tissue of Liza klunzingeri fishes of islands (Qeshm, Hengam and Hormoz) in Hormozgan province during summer to winter 2019. After biometry muscle tissues of 180 samples should be omitted were isolated and frizzed. Then the samples were prepared by acid digestion method and the amount of heavy metals was measured by using a flame atomic absorption device (700Contr AA model). The results should be omitted showed that the highest mean concentrations of studied metals (lead: 0.082 ± 0.009, nickel: 0.646± 0.07, zinc: 31.97±1.33 and copper: 0.881 ± 0.03 micrograms per gram)  were in Qeshm Island and the highest mean heavy metal concentration of iron (19.30± 0.75 Micrograms per gram) was in Hormoz Island and the lowest mean concentration of heavy metals (lead: 0.036 ±0.007, nickel: 0.348 ± 0.05, zinc: 15.13 ±1.06, copper: 0.657± 0.04 and iron: 12.13 ±0.4 Micrograms per gram)  were observed in Hengam Island. The concentrations of metals in the analyzed samples were lower than the international standards of the FAO, the WHO, the FDA, the Australian National Institutes of Health (NHMRC) and the UK Food and Drug Administration (UKMAFF) and statistically significant differences were observed. Also, the level of potential risk and risk index for non-cancerous diseases in adults and children in the muscle tissue of barley fish were less than 1. Therefore, according to the results of this study, the current use of this species of fish for human consumption will not pose a problem from the perspective of health and public health.

The aim of this study was to identify and compare the mineral micronutrients compositions, color and genetic structure differences between the wild and farmed Caspian Sea Beluga (Huso huso) sturgeon caviar, which plays an important role to caviar market transparency to prove farmed caviar quality and nutritional values and wild and farmed Beluga caviar genetic identification. Mineral micronutrients were measured by atomic absorption, spectrophotometric and flame atomic emission spectroscopy methods, color by colorimeter and genetic differences by PCR sequencing method. Results showed that, wild samples contained higher amounts of calcium, magnesium, phosphorus and potassium than farmed ones (P<0.05), while, iron, copper and zinc were higher in farmed samples (P<0.05). Sodium content had no significant differences between wild and farmed samples, 4239.43±2.72 and 4237.21±2.18 (µg/g wet weight) respectively (P>0.05). L value in wild sample was 28.29 and in farmed one was 46%, a value was 1.34 and 2.66% and b value was 10.72 and 16.27% respectively (P<0.05), ΔE (color differences) was 15.21 between two samples. Genetic structure had no significant differences between two samples. In conclusion, it can be said that, there was significant differences in mineral micronutrients contents and color but genetic structure did not show any significant differences between two samples.

This study was carried out in line with the Caspian Sea Central Plateau Water Transmission Program in the southern shores of the Caspian Sea and Goharbaran region in 2013-2014. Sampling was carried out monthly at 8 stations at depths of 5, 10 and 15 meters in 2 transects. The purpose of this study was to investigate the relationships between some physico-chemical parameters of water and TOM (total organic matter), distribution, abundance and biomass of different species of Amphipoda in half-lines, depths, stations and seasons. Overall, one species of Niphargoides caspius from the Gammaridae and four species of Stenogammarus similis, Stenogammaus macrorus, Stenogammarus carausuii and Stenogammarus compenus of Pontogammaridae were identified. A total of 15118 individuals of the benthic organisms were counted, in which, S. compresus and N. caspius with 68 and 2 percentages, respectively. Overall, the mean (± standard error) density and biomass of benthic organisms during the period were 128±14.08 ind.m-2 and 0.15±0.01 g.m-2, respectively. According to Spearman test, density of S. carausuii, S. macrorus and S. similis was significantly correlated with sedimentation (sand) (p<0.01). Multivariate cluster analysis based on Spearmanchr('39')s correlation coefficient on the relationship between density and biomass of different species of Amphipoda with some environmental parameters, grain size and total organic matter (TOM) of bed sediments showed that the members of this group belonged to a sand bed and dissolved oxygen are more strongly correlated in which could be due to ecological origin of Amphipoda groups.

In this study, surficial sediments along 9 stations (from Bilqan to Dizin and Varangeh_e Rood) were collected seasonally along 2017-2018 and water quality was assessed using enrichment index (EF) and Pollution load index (PLI).The percentages of sand, silt, clay in the sediment samples were determined (78, 17 and 5 respectively). The mean of Al, As, Cu, Fe, Ni, Pb, Cr, Zn, V, TP and TN in the sediment samples were 7.35±1.99%, 8.0±1.2 ppm, 41.0±30.2ppm, 3.56±0.53% , 24.33±4.87 ppm, 5.9-13.6 ppm and 21.8-28.8 ppm, 15.9±5.99 ppm, 36.08±11.45 ppm , 68.08±08.6 ppm, 88.9±23.3 ppm, 0.1±0.05% and 0.42±0.07% respectively. Based on cluster analysis, Asara and Shahrestanak (group1); Pool-e Khab and Gachsar(group2), Bilqhan, Varangh_e Rood, Hassankader and Dizin (group3); and Pool_e Choobi (group4) categorized into separate groups. In general, the concentration of nutrients and heavy metals in the stations did not exceed the PEL and SEL. The enrichment index for both chromium (0.2) and iron (0.8) showed a degree of non-enrichment at all stations. Other metals showed a low degree of enrichment and have low enrichment levels and, in terms of arsenic concentration, EF have been moderate to severe (4.9±1.1). According to the PLI index (1.35-1.9), all stations were more than one, so it can be concluded that all of them were polluted.

In this study, the effect of different salinity levels with salt of Lake Urmia was investigated on growth performance, body composition and some serum biochemical parameters of juveniles Caspian Kutum (Rutilus kutum). Fish with initial average weight of 1.05 ± 0.05g (±SD) were fed for 8 weeks in rearing tank. Juveniles Caspian Kutum were divided into four groups and treated with following preparation: control group salinity 0 ppt (fresh water), first treatment (salinity 5 ppt), second treatment (10 ppt) and third treatment (15 ppt). The results showed that the highest weight gain was observed in treatment 1 (p<0.05). Also, the Condition factor had significant differences between control and treatment 1 with other treatments (p<0.05). Survival was not affected by different salinity (p> 0.05). There was no significant difference in blood cholesterol levels between the experimental treatments, but there was a significant difference in hematocrit and glucose parameters (p<0.05). Body composition analysis showed that the experimental treatments had a significant effect on protein and fat levels but the moisture and ash levels were not affected by the experimental treatments. Generally, salinity level of 5 to 10 ppt of Urmia Lake salt had positive effect on growth, survival and blood parameters of juveniles Caspian kutum.

Ghost crabs are the largest invertebrates on sandy beaches around the world. The one of type of ghost crabs is Ocypode rotundata which is distributed on sandy beaches of Persian Gulf and Oman Sea. The aim of this study was discrimination of O. rotundata population using 33 morphometric characteristics selected of carapace, walking legs, abdomen, major chela by principle component analysis (PCA) in software of R. For this purpose, samples were collected at low tide by excavating (20-150 cm) in four zones of south and south western of Qeshm Island (Sakoo naft, Souza, Salakh, Kani). According to results, there were differences between individuals of some population in terms of investigated morphometric characteristics. On the other hand, most of the population showed overlapping which could not be separated together completely. Among the obtained morphological index traits are third walking leg length, body height, abdomen length, first part of abdomen width, fifth part of abdomen width, chela and merus length which can be reason for variety between individuals.

This study was conducted to evaluate the effect of different levels of dwarf elder extract on growth performance, survival rate and immune parameters of common carp. For this purpose, fish with an average weight of 15.1±0.3 g were distributed in 12 fiberglass veniero with 30 fish density and fed for 56 days with different levels of dwarf elder extract including 0 (control), 2.5, 5, and 10 g per kg of feed. Based on the growth results, final weight (32.7±0.7 g), weight gain (17.5±0.5 g), increased body weight (115.4±1.9 %), specific growth rate (0.98 ±0.04 %/day), feed conversion ratio (2.31 ±0.05), condition factor (1.47±0.04), and protein efficiency ratio (1.03±0.08) in 10 g of dwarf elder extract/kg diet were significantly different from other treatments (p<0.05). Results of this study showed that there was a significant difference in survival rate among 10 g/kg extract/kg of feed treatment with other experimental treatments, especially control treatment (p<0.05). Results showed that there was a significant difference in the amount of lysozyme activity (46.2±1.7 IU/ml), alternative complement pathway hemolytic activity (66.0±5.8 mg/dl) and serum IgM (38.1±0.5 mg/dl) among 10 g/kg extract/kg of feed treatment with other experimental treatments, especially control treatment (p<0.05). In general, effect of dwarf elder extract, especially at 10 g/kg of diet, on the growth parameters, survival rate and immune parameters of common carp fry was evaluated positively.

In the last two decades, the Caspian Sea has faced various ecological events, such as harmful algal blooms and increasing in the trophic level. It is necessary to conduct monitoring studies in this water body, because of applying the Caspian Sea for fisheries activities. The objectives of the present paper are the study of algal bloom potential and trophic level in the Iranian coastal of southern Caspian Sea up to 30m depth, during the year of 2018-2019 as well as the comparison of the obtained results to the condition in previous years. Boundary lines for the beginning of blooms (annual median+5%) based on the chlorophyll-a concentration, abundance, and biomass of phytoplankton were obtained 2.02 (mg/m3), 176 (million cells/m3), and 312 (mg/m3), respectively. The lowest percent frequency of bloom (13%) was recorded in spring and summer based on the chlorophyll-a, abundance, and biomass of phytoplankton, respectively. According to calculations based on the accumulation of the aforementioned parameters, water has excellent quality (oligotrophic state) in summer and moderate quality (mesotrophic state) in other seasons. An interannual study of trophic states showed oligotrophic, mesotrophic, oligo-mesotrophic, and mesotrophic level in 1996-97, 2009-10, 2013-2014, and 2018-2019, respectively. The highest seasonal abundance of species (187 cells/ml) was recorded in Pseudonitzschia seriata. This species is considering a serious ecologic problem and decreasing water quality in the winter season. The bloom potential of Pseudonitzschia seriata was obtained in the “medium density” group. It should be noted that the increasing trend of inter-annual trophic levels is the alarm of environmental health and show the ability of the ecosystem to thrive the harmful algal blooms. The environmental alarm is more emphasized in the central region (with a history of macroscopic toxic algal blooms) because the water quality in the central area (medium quality) was lower than in the eastern and western areas.

For this study 10 Arabibarbus grypus were caught with the same biometric conditions of each sex for two seasons. Then, 0.5 cm long specimen were taken from the anterior, middle and posterior regions of the intestine and placed in Boenchr('39')s solution. Subsequently, routine histological procedure was done and 4-6 µm section, stained with Haematoxylin-Eosin and periodic acid–Schiff. To determine the activity of digestive enzymes, raw enzyme extract was first prepared. The usual steps for measuring enzymes, such as homogenization, centrifugation, and finally were transferred to the autoanalyzer, and results obtained in terms of micromole per milligram of protein were expressed. The results of histological observations indicated that there were four layer of mucusa, submucosa, muscularis, and serousa, like other bony fish. The results of comparing the average activity of digestive enzymes between groups showed that the activity of amylase enzyme in all different regions of the intestine between male and female fish in cold and hot season was not significantly difference (p≥0.05). The activity of the alkaline phosphatase in all areas of the intestine in female increased significantly compared to male fish, especially in the cold season (p≤0.05). Also, there was no significant difference in the activity of lipase enzyme in all different areas of the intestine between male and female in both seasons (p≥0.05). Based on the results of this study, it was found that each part of the intestinal tissue has a structure appropriate to the active digestive enzymes in that area, which has differences and similarities with other species that have been addressed.

A mixture of vegetable and animal proteins (corn gluten, wheat gluten, processed soy flour, poultry by product, meat and bone meal and blood meal) that are chemically similar (protein, fat, carbohydrate and dry matter) and similar to amino acid profiles compred fish meal were replaced fish meal in diets with identical levels of protein (44%), energy (18 MJ /kg) at levels of  20, 40, 60 and 80% (MPP20, MPP40, MPP60 and MPP80). Juvenile Huso huso with average weight of 167± 6.5 g were fed diets to saturation and their growth indices, carcass composition, hepatosomic and visceral indexes were studied. The final weight, final length, condition factor, weight gain, body weight precent, specific growth rate, daily growth, feed conversion ratio and protein efficiency ratio were not affectrd with diets (p>0.05). Carcass protein of fish fed MPP60 and MPP80 were significantly decreased compared to fish fed diet based on fish meal, while fish carcass fat increased significantly in these fish (p<0.05). There was no significant difference in hepatosomatic and visceral index in fish fed diets based on fish meal (p>0.05). The results of this experiment showed that it is possible to replace 80% of a mixture of animal and vegetable proteins with fish meal without adversely affecting growth indices, hepatosomal and visceral index  of  Huso huso in growth rate period.

The main objective of the current study was to investigate the effects of ethanolic extract of the Salicornia plant on growth indices, body composition and immunity of the western white leg shrimp juveniles. Experimental treatments consisted of 0 (control), 1, 3 and 5 grams of ethanolic salicornia extract per kg of base diet. Each treatment consisted of triplicates containing 50 juveniles at each tank. Shrimp were fed 3 times daily about 5% of body weight for 45 days experimental period. At the end of the experiment period, 5 shrimp from each tank were randomly selected and growth parameters, body composition analysis and immunity indices were measured. The results showed that there was a significant difference in each of the measured growth indices between the control and other treatments and the best performance was observed in the diet containing 5 grams of ethanolic extract (p<0.05). Body compositions and immunity indices results showed that the best performance was related to 5 g ethanol treatment and had a significant difference with other treatments (p<0.05). The output of the current research revealed that the usage of the Salicornia extract has positive effects on growth, body composition and immunity of the western white leg shrimp. Therefore, usage of salicornia extract of 5 g/Kg is recommended in the shrimp farms.

Due to the many effects of dietary nucleotide such as increasing the immune system, reducing stress, disease resistance, better growth and longer survival, the present study was designed and performed to investigate the effect of dietary nucleotide supplementation (ascogen) on hematological parameters and carcass composition of Siberian sturgeon (Acipenser baerii). Ascogen has optimal levels of RNA and nucleotides. In this regard, 450 fish (39.77 ± 10.24 g) were distributed in 15 tanks (300 liters). Fish were fed with 5 nucleotide treatments including control treatment (0 g/kg), treatment 1 (0.2 g/kg), treatment 2 (0.4 g/kg), treatment 3 (0.6 g/kg) and treatment 4 (0.8 g/kg) was selected in 3 replications for 63 days. Fish were fed about 3% of body weight in 4 meals. At the end of the period, it was determined that the fish were fed with treatments 3 (0.6 g/kg) and 4 (0.8 g/kg) in terms of hematological indices and treatment 4 (0.8 g/kg) in terms of carcass composition had better performance than other treatments. Therefore, treatments 3 (0.6 g/kg) and 4 (0.8 g/kg), especially treatment 4 (0.8 g/kg) had the most positive effect and nucleotides were able to induce their positive effects in fish and improved conditions and increased efficiency.

This research was carried in order to study of pathology and changes of some hematology indicators of indigenous and French Rainbow trout fish after following with Aeromonas hydrophila. For this research, treatments were performed in eight treatments and each treatment with three replications (each replicate containing 10 rainbow trout fish with an average weight 16±0.36 g). two treatments as a negative control (including of indigenous and French fish without bacterial injection), Two treatments as a positive control (including of indigenous and French fish with serum physiology injection), two treatments including indigenous fish with 106 and 108 CFU/ml Aeromonas hydrophila bacteria and two treatments including French fish, which were injected with 106 and 108 CFU/ml of Aeromonas hydrophila by intra-peritoneal method. After 20 days, to determine the values of some hemotology parameters including counts of white blood cells (WBC), red blood cells (RBC), hemoglobin, hematocrit, and MCV, MCH and MCHC indices, blood samples were taken from 6 fish of each treatment, and then, in order to study of pathology of the tissues of the kidney, liver and spleen, fishes were fixed in 10% formalin solution. The present study, the results showed that the hematocrit, hemoglobin and counts of red blood cells decreased significantly in the treatments of infected with bacterial infection of Aeromonas hydrophila compared with the control groups, and the number of white blood cells and neutrophils increased significantly. Lesions such as mild degeneration lesions in liver cells and tissue texture and severe cytoplasmic vacuating of liver cells and complications such as degeneration and necrosis of renal tubules and hyperemia, edema and lose of spleen pulmonary defence cells, the most important changes in tissue pathology were in experimental treatments compared to control. The highest survival rate was observed in indigenous Rainbow trout control group without bacterial injection and with serum physiology injection. Due to the greater capability of internal race resistance along with management measures that have been able to increase survival rates, improvement of environmental conditions and elimination of stressors can be effective in reducing Aeromonas lesions.

In this study, Meyghan Wetland in Arak City (Central Iran) was evaluated to estimate the cyst and biomass stocks of Artemia and their relationship with various factors, abiotic such as WT, DO, pH, water depth, salinity and transparency and numbers of phytoplankton as biotic factors. For this purpose, monthly sampling was performed during 2019 from 18 stations in Mighan Wetland. The amount of cyst (28.875 t), and biomass (23.673 t) artemia in the water of Mighan wetland were determined. The density and type of phytoplankton were also measured. The results showed that the maximum amount of cyst and biomass was observed in December, 1076 and 457.11 per liter respectively. Inverse relationship between cyst and biomass with water temperature, pH, and phytoplankton density and in contrast a positive and significant relationship was observed with dissolved oxygen and salinity. In general, the results showed the possibility of cyst harvesting (5.405 tons according to the method of preserving 22 cysts per liter of water or 2.8875 tons according to the method of 10% harvesting possibility) in October, December, February and March, which the best month for exploitation was in December. The possibility of biomass harvesting (9.469 tons after calculation of 4.3 tons of biomass needed for feeding Felamingo and Shelduck) was also recommended only in December based on the depth of the Secchi disc.

The present study was conducted to evaluate the effect of supplementation of Enterococcus foecalis “subspecies NBRC 100480 on the growth performance, blood parameters and digestive enzymes activity of rainbow trout (Oncorhynchus mykiss) for 8 weeks. The experiment was conducted in a completely randomized design with 240 of rainbow trout with average weight of 12±1.20 g in 4 treatments and 3 replicates (n=20 in each replicate) and included: control group without using of supplementation of probiotic and another groups the amounts of this probiotic supplement were 3×108 , 5×108 , 8×108 CFU/g feed. The results showed that the highest final weight and the lowest FCR were observed in treatments containing 5×10 8 CFU/g feed and showed significant difference with control and another treatment (p<0.05). The highest protease enzyme activity, RBC, Hb and Htc were observed in treatments containing 5×108 and 8×108 CFU/g feed (p<0.05). Overall we concluded that the using of 5×108 CFU /g feed of E. foecalis in the diet could improve growth, blood parameters and protease enzyme activity of rainbow trout.