zabih ollah pajand

The attention to the control of aquatic ponds and the optimum use of water consumption can reduce pollution of the environment and maintenance ecological conditions of the region. This study investigated the effect of artificial wetlands on the reduction of ammonia and nitrate factors and also physical and chemical changes loading in wastewater to improve water efficiency in stellate sturgeon ponds over a ten-month growth period. To conduct this research, 5 ponds (4 m-2) and 5 cement canals were used. Three fiberglass ponds were used to culture of stellate sturgeon under the same conditions, two fiberglass ponds were used for culturing of Hediste diversicolor and Gammarus (Gammarus aequicauda) larvae, and cement channels were used to establish reed plants (Phragmites australis) in the treatments in the first to third rows, respectively. At this study was used 50% recyclution water and 50% freshwater. The ammonia and nitrate factors were measured in all ponds monthly. In the output of the reed plant, the highest percentage of ammonia (NH3-N) and nitrate (NO3-N) removal was related to the water that was passed through the gammarus ponds and stellate sturgeon, respectively. The results of percentage reduction of wastewater nutrients among the treatments showed that the highest ability to remove ammonia (15.6%), and nitrate (24%), was observed in the ponds of Phragmites australis and it also economically plays an important role due to the lack of food cost for feeding worms and Gamarus.

The ability of fish adaptation to different salinities depends on osmotic, ionic and biochemical regulation, on the other hand, transferring fish to salt water causes the development of their osmotic and ionic homeostasis mechanism. The adaptation of stellate sturgeon (Acipenser stellatus) in four weight treatments including 0.5-1, 1-3, 3-5 and 5-10 g in water with four salinity levels of 0.5, 4, 8 and 12 g/l during 8 phases and each experiment was performed in 4 predicted treatments. Each experiment was carried out in a period of about one month along with feeding with live foods, preferably gammarus, Nereis worms, and chironomidae larvae at the saturation level of 6 times a day, as well as daily siphoning and water changes. Osmolarity and factors of chloride, calcium, sodium and potassium were measured in fish blood serum. In the examination of the compatibility and adaptability of this fish with the conditions of changing salinity, the results showed that with increasing salinity, the levels of potassium, sodium, chloride and blood osmolarity increased. The stellate sturgeon are able to adjust the osmotic pressure and ionic composition of their blood serum when they migrate from hyperosmotic to hypoosmotic environment or vice versa. The blood osmolarity of fish with a weight of 5-10 g was higher than other weights, and the lowest osmolarity was observed in fresh water (0.5 g/l). The results of this study showed that the amount of potassium in the blood serum decreased with the passage of time and the increase in salinity, and increased the amount of sodium and calcium in the blood serum.

This study aimed to evaluate the effects of feeding with different types of live feeds on growth performance, survival rate, body composition, and fatty acids profile of great sturgeon (Huso huso) larvae during short-time weaning to dry feed. A total of 1200 great sturgeon larvae with a mean initial weight of 0.43±0.01g were distributed randomly into twelve 80-L circular fiberglass tanks (100 larvae per tank) with three replicates. Afterward, the fish were fed with frozen chironomid larvae (T1), frozen Artemia biomass (T2), and a combination of them (T3). The control group © received only a commercial dry feed (0.5 mm: protein 55.59%, lipid 21.12%, ash 11.76%, and moisture 7.96%) throughout the feeding trial. For weaning, the live feed was reduced by 15% every two days, and the dry feed ratio was also gradually increased. According to the results, the final weight (4.99±0.16g), weight gain (4.57±0.17g), body weight increase (1081.53±72.75%), and specific growth rate (11.75±0.29%/day) were significantly higher in T1 than in other groups (p<0.05). The survival rate (56.50±1.32%) significantly decreased in the control group © (p<0.05); however, no mortality was observed in the group fed chironomid larvae (p<0.05). The crude lipid (1.32±0.08%) and moisture (80.98±0.17%) levels of T1 were higher than other groups, and the crude protein content was significantly higher in T3 (11.26±0.39%) and C (11.44±0.44%) than T1 (9.23±0.39%) and T2 (9.67±0.28%) groups (p<0.05). There was a significant decrease in total n-3 LC-PUFA fatty acids (9.53±0.04%) in T3 than in T1 (11.02±071%) (p<0.05). The EPA/DHA ratio in T1 was significantly higher (0.45±0.03%) than other treatments (p<0.05). Consequently, the administration of frozen chironomid larvae is recommended during a 21-day adaptation period of great sturgeon larvae to the dry feed, due to the optimizing effects on growth indices, survival, and fatty acid contents.

The salinity and feeding frequency are two fundamental challenges in breeding stellate sturgeon (Acipenser stellatus) juveniles both for aquaculture and restocking purposes. Osmoregulation indices including, osmolarity enzyme activity, and chloride cells count and size in the gill tissues of 810 stellate sturgeons (weight 10.96±0.89 g and length 12.64±0.96 cm) in 9 treatments combining three salinity levels with three types of feeding during eight weeks of rearing. The treatments included two, four and six times (2T, 4T and 6T) of feeding in combination with zero,6 and 12ppt salinities (0‰, 6‰and 12‰). Osmolarity and activity of Na+-K+-ATPase were affected by salinity, but feeding frequency had no significant impact on them(P>0.05). The amount of sodium (Na+) increased in 2T,12‰, and potassium(K+) increased in 2 T,6‰. The highest number of chloride cells was observed in treatments with the most elevated salinity (12 ppt). The frequency of feeding at the same salinities did not affect the number of chloride cells (P>0.05). The area and perimeter of chloride cells in 2T,12‰ to 6T,12‰ improved with increasing salinity (P<0.05). Changes in the number and size of chloride cells of gill filaments were observed with the least tension after two months of rearing with 2, 4, and 6 times of feeding in brackish water with a salinity of 12‰.

Due to the drought and water shortage of rivers in the southern basin of the Caspian Sea, especially during the release of these fish and illegal fishing of juveniles in the river, to increase the survival rate, it is better to release these fish in the river or directly into the sea. Acipenser stellatus were examined in different weights with four treatments of 0.5-0, 0.5-0, 4-9 and 9-13 salinity per thousand (ppt) and each treatment in three replications. The experiment was performed for a period of one month along with feeding with live food, preferably Daphne, Gamarus, Nereis worm with a saturation of 6 servings per day and siphon and water change. Daily losses were collected and recorded during the period. The results showed that the percentage of survival in salinities of 0.5-0 and 4-5 g / l was significantly higher than salinity of 4-9 and 9-13 g / l in the weight range of 0.5-1 g. It was 0 g (df = 3, F = 68.800, P = 0.000). Also, the percentage of survival in salinities of 0.5-0 and 4-9 g / l was significantly higher than the salinity of 13-9 g / l in the weight range of 1-3 g (df = 3, F = 7.558, P = 0.010). Survival percentage in salinities of 0.5-0 and 0.5-4 g / l was significantly higher than salinity levels of 4-9 and 13-9 g / l for weight of 3-5 g (df = 3, F = 8.933 P = 0.006). Survival percentage in different salinities in the weight range of 5-10 g showed a significant difference (df = 3, F = 68.800, P = 0.000). According to the results, it is suggested that juvenile Acipenser stellatus are first released in the estuary at salinity below weight range of 8 g / l and enter to the sea after adapting to salinity.Due to the drought and water shortage of rivers in the southern basin of the Caspian Sea, especially during the release of these fish and illegal fishing of juveniles in the river, to increase the survival rate, it is better to release these fish in the river or directly into the sea. Acipenser stellatus were examined in different weights with four treatments of 0.5-0, 0.5-0, 4-9 and 9-13 salinity per thousand (ppt) and each treatment in three replications. The experiment was performed for a period of one month along with feeding with live food, preferably Daphne, Gamarus, Nereis worm with a saturation of 6 servings per day and siphon and water change. Daily losses were collected and recorded during the period. The results showed that the percentage of survival in salinities of 0.5-0 and 4-5 g / l was significantly higher than salinity of 4-9 and 9-13 g / l in the weight range of 0.5-1 g. It was 0 g (df = 3, F = 68.800, P = 0.000). Also, the percentage of survival in salinities of 0.5-0 and 4-9 g / l was significantly higher than the salinity of 13-9 g / l in the weight range of 1-3 g (df = 3, F = 7.558, P = 0.010). Survival percentage in salinities of 0.5-0 and 0.5-4 g / l was significantly higher than salinity levels of 4-9 and 13-9 g / l for weight of 3-5 g (df = 3, F = 8.933 P = 0.006). Survival percentage in different salinities in the weight range of 5-10 g showed a significant difference (df = 3, F = 68.800, P = 0.000). According to the results, it is suggested that juvenile Acipenser stellatus are first released in the estuary at salinity below weight range of 8 g / l and enter to the sea after adapting to salinity.Due to the drought and water shortage of rivers in the southern basin of the Caspian Sea, especially during the release of these fish and illegal fishing of juveniles in the river, to increase the survival rate, it is better to release these fish in the river or directly into the sea. Acipenser stellatus were examined in different weights with four treatments of 0.5-0, 0.5-0, 4-9 and 9-13 salinity per thousand (ppt) and each treatment in three replications. The experiment was performed for a period of one month along with feeding with live food, preferably Daphne, Gamarus, Nereis worm with a saturation of 6 servings per day and siphon and water change. Daily losses were collected and recorded during the period. The results showed that the percentage of survival in salinities of 0.5-0 and 4-5 g / l was significantly higher than salinity of 4-9 and 9-13 g / l in the weight range of 0.5-1 g. It was 0 g (df = 3, F = 68.800, P = 0.000). Also, the percentage of survival in salinities of 0.5-0 and 4-9 g / l was significantly higher than the salinity of 13-9 g / l in the weight range of 1-3 g (df = 3, F = 7.558, P = 0.010). Survival percentage in salinities of 0.5-0 and 0.5-4 g / l was significantly higher than salinity levels of 4-9 and 13-9 g / l for weight of 3-5 g (df = 3, F = 8.933 P = 0.006). Survival percentage in different salinities in the weight range of 5-10 g showed a significant difference (df = 3, F = 68.800, P = 0.000). According to the results, it is suggested that juvenile Acipenser stellatus are first released in the estuary at salinity below weight range of 8 g / l and enter to the sea after adapting to salinity.v

The aim of this study was to introduce the Karganrood River as one of the safe routes for releasing sturgeon fry. Karganrood River is located in the west of Gilan province in Talesh city. In the river, 3 sampling stations were considered. The range of changes in dissolved oxygen was 8.21 to 8.87 mg/l. The pH value ranged from 9 to 9.43. The amount of ammonia in station 3 was highest and in station 1 was the lowest amount. The amount of nitrite and nitrate was reported the highest in station 3. Oxygen and pH at releasing time were 8.46 mg/l and 9.24, respectively. Biomass of chironomidae, Gamarus and insect larvae in station 3 were significantly more than stations 1 and 2 (P<0.005). The amount of organic matter in stations 1 and 3 was significantly more than station 2 (P<0.005). In the 3 stations, sand percent was significantly more than clay and silt (P<0.005). Study on percent of sediment granulation in 3 stations showed that there is no significant differences in clay percent among stations 1, 2 and 3 (P>0.005) and silt was present only in station 1. One thousand juveniles of Stellate sturgeon (Acipenser stellatus) with an average weight of1.56 ±0.58g and an average length of 8.58±1.23cm were released at the third station. 95 juveniles of Stellate sturgeon were tracked from releasing place up to near the estuary. After 7 hours from the releasing time, 4.1% of total released juveniles were caught by the net located in the estuary.

This study aimed to investigate the effects of interaction between nitrite and different salinities on blood, immunity, and stress parameters in juveniles of stellate (Acipenser stellatus) in two stages. In the first stage, the lethal concentration (LC50 96h) of nitrite in different salinities (0, 4, 8, and 12g/L) to juveniles of stellate was determined. In the second stage, 240 juveniles of stellate (with a mean weight and length of 15.23±2.17g and 17±1.96cm) were exposed to half (50%) of LC50 96h (37.56, 46.77, 120.80, and 176.579mg/L) under the same salinities for 4 days (8 treatments, triplicate). The results showed that the highest mean of white blood cells and neutrophils was in Treatment 7, the highest mean of red blood cells, hemoglobin, MCV and hematocrit was related to treatment 5 and the highest mean of eosinophil belonged to Treatment 8 (P<0.05). Moreover, the highest IgM and total immunoglobulin, lysozyme, cortisol and glucose, and lactate was found in treatments 8, 7, 4, and 3, respectively (P<0.05). The increased nitrite concentration in subjects exposed to salinity plus half of the LC50 96h of nitrite significantly increased the tolerance and immunity parameters and reduced the stress level of subjects. This indicates that salinity could reduce the toxicity of nitrite to subjects. Blood indices also considerably changed in subjects exposed to the same conditions. It can be hence concluded that saline or brackish water (mixed with freshwater, 0 to 12g/L) plus half of the LC50 96h of nitrite is suitable for the culture of stellate juveniles.

The aim of this study was to evaluate the effect of feeding frequency and salinity on blood factors, immunity and stress indices of farmed stellate sturgeon (Acipenser stellatus) in 1399. For this purpose, 810 juvenile stellate sturgeon (average weight 12.24 g) in 9 treatments and each with three replications with three salinity levels and three feeding frequency levels were considered. Treatments included: Treatment 1: Twice daily feeding and zero salinity, Treatment 2: Four times daily feeding and zero salinity, Treatment 3: 6 times daily feeding and zero salinity, Treatment 4: Twice daily feeding and 6 g salinity Per thousand, treatment 5: four times a day feeding and salinity 6 grams per thousand, treatment 6: six times a day feeding and salinity 6 grams per thousand, treatment 7: twice daily feeding and salinity 12 grams per thousand, treatment 8: Four times feeding load 12 grams per day and salinity per thousand and treatment 9: 6 times per day and salinity 12 grams per thousand. The fish were reared for eight weeks. Blood samples were then taken from the fish. The results showed that in most cases, the number of white blood cells, red blood cells, blood indices in treatments 4 and 6 were higher than other treatments (P<0.05). Also, the amount of IgM, lysozyme and total immunoglobulin in treatments 3 and 4 were higher than other treatments (P<0.05). The results of stress indicators showed that the serum glucose and cortisol levels of fish had a statistically significant difference (P<0.05). According to the results, it can be said that it is possible to breed stellate sturgeon in different salinities and increasing the number of feedings helps this fish to withstand different environmental conditions. However, due to economic issues and labor costs, it is recommended to feed the fish 4 times a day.

Laboratory examinations on the effect of different densities on production of beluga and Nereis diversicolor worm and purification of total organic matter was carried out in an integrated system. Juvenile beluga with initial weight of 140.44±0.32 g were reared during 60 days with three densities of 2, 4 and 8 fish per tanks. Outlet water of the fish tanks was entered to the Nereis worm tank then was entered to the biofilter tank then after cleaning on this tanks water was returned again into the system. In this system, the Nereis worm was used both as a bioremediator and also byproduct. The results showed that growth factors of fish and increasing of density have related inversely. So that the maximum percentage of body weight increase and weight gain of beluga were 93.86±1.5% and 124.61±1.7 g respectively in low density. However, increased density caused increases in production of fish per unit area. So that highest final biomass of juvenile’s 5.28±0.09 kg/m2 were observed in high density. The lowest amount of total organic matter on the substrate with 2.66±0.94 g/mg was related to high density. The results of this experiment showed that the reliable stocking density is 8 per tank for fish production and bioremediation efficiency of system.

This study was conducted to test the effect of bioremediation the polychaete worm Nereis diversicolor in order to removal of wastewater nutrition derived different densities Huso huso. The aim of this study was determination of different densities for creating the equivalence for rearing of N. diversicolor and H. huso rate in the integrated culture system. Three different densities of H. huso culture with N. diversicolor fed with fish feed waste were considered at water temperature 23°C for 8 weeks. The obtained results demonstrated that N. diversicolor could grow via feeding with the fish waste water. The pure production and survival rate of harvested Nereis in NWF2 treatment was significantly higher than other treatments (P<0.05). The highest removal efficiency of waste water including NO2-N (91%), TSS (89%),  BOD5 (85%),  PO4-P (65%), total phosphorus (63%), total nitrogen (56%), NH3-N (35%), were seen in different treatments. The removal efficiency of waste water nutrition was decreased without use of N. diversicolor. Also, removal efficiency of NO3-N did not occur with presence of the worm. The obtained results demonstrated that increasing of worm growth, decreasing waste water nutrition and achieving of secondary production made system efficiency. The use of worm biomass as a waste treatment method could economically play important role.

The study of effect four diets formulated containing vegetable oils including canola and corn oils and their mixture, in three replications each, was carried out to feed N. diversicolor during two months. At the end of the experiments, growth performance in each treatment included total biomass, L3 length, specific growth rate (SGR), body weight increase (BWI), and survival rate were measured. Biochemical composition including total protein, total fat and fatty acid profile of diets and worms body carcass were analyzed. The results showed that there was no significant difference in the growth performance of worm from diets containing different oils with control treatment (worms fed from diet of without oil). The results indicate that the fat in the diet has no effect on the growth of the worms, but the presence of these vegetable oils in carcass composition was important. The results of this study showed that all saturated and unsaturated fatty acids in the diet, except of the control treatment in the N. diversicolor, were higher than their dietary. In the present study, N. diversicolor, fed from diet containing of canola oil, had the highest ⍵-3 fatty acids. The highest EPA level and ratio of ⍵-3/⍵-6 in the worms fed canola oil were higher than formulated diet containing canola oil. Totally, treatment 1, including diets containing canola oil, was more suitable for increasing the growth perfoermance and unsaturated fatty acids of worm than other treatments.