جستجوی مقالات مرتبط با کلیدواژه « oncorhynchus mykiss » در نشریات گروه « محیط زیست »

At present, many cold water fish farms in the country use reused water to produce fish, but the effects of its using on fish muscle quality are not well known. The aim of the present study was to compare the muscle quality of rainbow trout (Oncorhynchus mykiss) raised in two open and partial reuse water systems. For this purpose, young trout with a stocking density of 20 kg/m3 and a loading density of 1 L/min/kg of fish was studied in two an open system (100% make-up water) and a designed partial water reuse system (with a reduction of 80% make-up water and its replacement with the reused water) for 45 days. Four times of water recirculation caused an increase of 6.7 and 6.5 times in the amount of water total ammonia and total phosphorus compared to an open treatment, respectively. Crude protein, crude fat, pH and moisture percentage showed significant differences between two treatments. In contrast, there were no significant differences in water holding capacity, cooking loss, texture analysis (hardness, adhesiveness, resilience, cohesiveness, springiness, gumminess and chewiness) and color indices of L*, a* and b* between two treatments. Consequently, the reuse of water to the same extent as the present designed protocol does not have very obvious changes on many studied muscle quality factors of fish.

In recent years, the application of herbal compounds has replaced artificial supplements in the fisheries due to their benefits. This study was performed to investigate the effects of Mentha piperata and Mentha Pulegium extracts on some blood and biochemical parameters in Oncorhynchus mykiss. For this purpose, 320 fish were evaluated in a completely randomized design with six treatments and four replications in a farm around Kermanshah Province. Experimental groups included (1): control group (basic diet), (2): treatment containing 1% Pennyrile, (3): treatment containing 2% M. Pulegium, (4): treatment containing 1% M. piperata, (5) treatments contained 2% M. piperata and (6) combination treatments (1% of each extract). Blood parameters including white and red blood cells, globulin, hemoglobin, and biochemical parameters, including albumin, glucose, triglycerides, and the enzymes alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase were evaluated. According to the results, the combination of M. pulegium and M. piperata extracts resulted in more white blood cells, red blood cells, and hemoglobin compared to the individual levels of both mint extracts. 1% M. piperata extract had the greatest effect on blood globulin count. The most significant effect on albumin content was observed in 2% M. piperata extract group. The highest mean blood glucose and albumin were found in the fish received 2 percent of M. piperata. Also, the highest levels of and the lowest triglyceride were observed in the fish supplemented with M. piperata extract and the combination of M. piperata and M. pulegium extracts, respectively. Higher levels of both M. pulegium and M. piperita L extracts increased the levels of alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase enzymes. According to the results of the study, it seems that in physiological conditions, the use of M. pulegium and M. piperata extracts can improve the physiology of fish while improving the function of the immune system and some blood biochemical parameters.

The aim of  this study conducted in Gonbad Kavous aquaculture laboratory was to  determine MATC and LOEC of ZnSO4 in fish using tissue lesion examinations. To do this, rainbow trout (Oncorhynchus mykiss) juveniles (6.18±1.33 g) were exposed zinc sulphate over 96 hours (in December 2021). Zinc sulphate salt was used to examine toxicity of zinc. The lethal dose of zinc for Oncorhynchus mykiss was 21 mgL-1 over 96 hours. According to the linear regression and relationship between the percentage of mortality and different concentrations of zinc, the LC50 (median lethal dose) was obtained 11.54 mgL-1 for Oncorhynchus mykiss. However, acute toxicity of zinc sulphate showed that mortality was  directly proportional to the concentration of the zinc sulphate, whilst there was no mortality in the control treatment. No behavioral changes were observed in control treatment over the experiment. Microscopic studies showed that the common lesions of gill in fish exposed to zinc lethal concentration were hyperplasia, edema, hyperemia, hemorrhage and expansion of secondary lamellae. Therefore, the results and information obtained in this study can be applicable in ecological risk assessment studies.

This study was conducted to evaluate the effects of different levels of Mix oilon growth performance and survival rate of Oncorhynchus mykiss inchallenging with Yersinia ruckeri. For this purpose, four groups of fish with mean initial weight of 31.1±0.1 g were raised for 8 weeks in cement tanks, including 80 fish in each tank and feeding with different levels of Mix oil(with concentrations of 0, 50 ppm, 200 ppm and 400 ppm, 3 replicates for each treatment). At the end of the trial, growth performance, and survival rate of fish inchallenging with Y. ruckeri were determined in different groups. Results showed that O. mykiss fed on diet supplemented with 400 ppm of Mix oil had significantly higher growth factors (body weight increase, specific growth rate, protein efficiency ratio, average daily growth) and survival rate compared to other treatments (p < 0.05). Based on the results, using of Mix oil, especially at the level of 400 ppm can improve the growth performance and survival rate of O. mykiss inchallenging with Y. ruckeri.

This study was carried out in a brackish water earth farm in Bafgh, to use wastewater of earth ponds in order to increase production in rainbow trout earth farms. It was performed in 2 treatments with 2 replications. For this purpose, four 0.5ha earth ponds (two of those with 30 m3 round cement ponds at the end and others without cement ponds) were made. The wastewater of culture earth ponds flew in cement ponds through pumping and gravity. The cement ponds aerated with splash aerator during nights. The average initial weight of fish for stocking in all ponds was 25 g and the density of stocking was one and 70 fish per square in earth pond and cement pond, respectively. During about 120 days’ culture period, water temperature and salinity were 14±4 °c and 12.8±1 g/l, respectively. The results of some chemical factors measuring in cement ponds indicated that none of them was critical during the culture period. There were significant differences among treatments on some growth factors (p<0/05). According to The results, through reusing of earth ponds wastewater, yield quantity and production income increased up to 31% and 41%, respectively.

To study the effect of Lavandula officinalis essence on growth indices and the blood and immunology parameters of Oncorhynchus mykiss, an experiment was conducted as compeletly randomized block design with four treatments in 3 replications. Experimental treatments included 0.5, 1 and 2 ml essence in 1 Kg of diet. Control treatment also was kept without the use of essence and with the same condition compared other treatments. According to the results, the highest percentage increase in weight, length, Special Growth Rate, Survival Percent and Fish Net Production were observed under treatments of 1 and 2 ml essence in 1 Kg of diet. Diatary Conversion Ratio significantly was decreased with an increase of essence values. The highest RBC, WBC, MCHC and Neutrophilis were observed in 2 ml essence in diet. Amount of HB, MCV, MCH, Monocytes and Eosinophils were not affected under different treatments of essence comparison with control. The results showed that immunology system of O. mykiss such as Lysosomal enzymes, SOD, IgM and Total Immunoglobulin of Serum were increased with an increase of essence amounts. Overall, addition of L. officinalis essence especially 1 and 2 ml in O. mykiss diet caused positive and significant effect on some growth indices and the blood and immunology parameters of O. mykiss. This is probably due to the compounds such as phenols, tannins and monoterepen which are present in the L. officinalis essence. Therefore, it is recommended as a dietary supplement in the basal diet.

In this study, for determining the effects of Glyphosate (Roundup) herbicide on certainsanguine factor of Salmon weighing 150-200 grams under qualitative stable conditions of water, in 4 treatments of 30 (three experimental group and one control treatment with three replicates) in a concentration of 25, 50and 75 percent LC50 96h have used. Over the experiments some factors like:  pH, hardness, water temperature and dissolved oxygen which were measured respectively between 7-8.4 mg/l, 22±1 degree centigrade, above 7 PPM. The experiment duration was for 10 days and every 5 day sampling applied. Results from histological pathology It also showed that the liver and gills were in the presence of glyphosate poison It leads to symptoms such as hyperemia, cellular atrophy, bile duct, necrosis, Cloudy swelling and sinusoidal space in the liver and hyperemia, hyperplasia, necrosis, Primary and secondary filament adhesion, cramping, wailing, The shortening of the secondary gill blades in the gill tissue Over time, these symptoms increase.

The main goal of the current study is to evaluate the impact of dietary herbal On Some Of The Hematological, Biochemical and Immune Parameters Of  Rainbow Trout(Oncorhynchus mykiss). This project was conducted at Caspian sea research institute of ecology from 2017 to 2018. Totally 180 rainbow trout with an average weight of 28.8g were randomly distributed to 9 fiberglass tanks with area  and depth of 1m2 and of 0.6 m.  The experiment lasted for seven weeks and the rainbow trout were fed by three different diets as follows: 1. Commercial pellet contained no herbal additive (control diet) 2. Commercial pellet contained 2% dietary herbal and 3. Commercial pellet contained 4% dietary herbal.  At the end of the trial, blood samples were collected to determine some hematological, biochemical and immunity parameters in different groups and compared to one another. Results showed that 4% dietary herbal can enhance the non specific immune system of  O.mykiss . Thus,addition of dietary herbal at 4% is  recommended  in    improve immunostimulants in rainbow trout.

Probiotics are generally defined as a live microbial food supplement which improve the balance of the host animal’s intestinal flora and the absorption of nutrients from the intestine. The aim of this study was to evaluate the effect of different levels of Lactobacillus casei</em> (PTCC1608) on survival andgrowth performanceof rainbow trout (Oncorhynchus mykiss</em>)fingerlings. Four thousand eight hundred fingerlings (average weight 32.6±5.5g) were randomly divided into 4 groups with three replicates (each with 400 fish). The control group fed with basal diet and the other groups were fed with 5×106</sup> (A), 5×107</sup> (B) and 5×108</sup>(C) CFU/mL L. casei</em> for 60 days. Biometry of specimen was down at 0, 30 and 60 days of study and growth performance rate evaluated. Results showed that fish were fed with 5×106</sup> (A) of L. casei </em>had significant impact (P<0.05) on growth performance. The specific growth rate (SGR), BWG and RGR had best performance at 5×106</sup> (A) of L. casei </em>andshow Significant differences compared with control treatment (P<0.05), while in the diet fed diet with 5×108</sup>(C) CFU/mL of L. casei</em>, some growth and survival indices decreased compared to the control group (P<0.05). There was no change in growth indices in diet fed with diet containing 5×107</sup> (B) CFU/mL of L. casei</em> compared to control in different stages of sampling. Survival rate was significantly different between treatments, so that the highest losses were related to 5×108</sup>(C) CFU/mL of L. casei</em>, which had a significant difference with control group. Results showed that adding 5×106</sup> (A) of L. casei</em> to rainbow trout diet as the most suitable concentration, improved the fish growth indices, but the higher concentrations of this probiotic has negative effects on growth.

Light is one of the most important factors affecting the growth and survival of larvae in fish. In a 55-day experiment, the effects of light color and photoperiod on hatching percentage, survival rate and larval growth indices in rainbow trout (Oncorhynchus mykiss</em>) were evaluated. Three light colors red, white and yellow  and four light periods (20 D / 4 L, 16 D / 8 L, 10 D / 14 L, 4 D / 20 L and 0 D / 24 L)  and natural situation as control group were tested in three replications.The results of this study showed that the highest percentage of hatching (94.86%) was observed in red light with darkness of 20 hours and the lowest (77.13% and 77.33%) in yellow and red light in 24 hours of brightness (P <0.05). Twenty days after hatching, the highest survival percentage and mean weight of larvae were observed in treatment with shorter photoperiod and red light, which had a significant difference with other treatments (p <0.05); however, different photo period and light colors did not significantly affect the mean larval length at the end of the twentieth day After 55 days of feeding, a significant increase in weight, the best feed conversion ratio and the highest specific growth rate were observed in larvae that were exposed to longer photoperiod and yellow light (p <0.05). In general, in the pre-hatch period, red light with longer darkness, and after-hatch yellow and white light with longer brightness can be effective in increasing hatching and growth.

This study aimed to evaluate the Sub- lethal toxcity effects of 2, 4- D+ MCPA herbicide after 2 week and 3 week on some hematological indices and liver enzymes of rainbow trout, Oncorhynchus mykiss. After determining LC50 by probit model, induced sub- lethal concentration (1/9 LC50) 0.11 mL/L (0.11 mL/L of  this herbicide equal 40 mg/L, 2, 4- D, 35 mg/L MCPA ) of  this herbicide were studied.. Blood samples of rainbow trout with weight mean 97 g were taken in the 72 hours following exposure to sub- lethal  concentration  of 2,4,D- MCPA herbicide after 2 week and 3 week with fish that were not exposed. The results showed that 2, 4, D- MCPA herbicide could changes in blood parameters and liver enzymes of rainbow trout by reducing red blood cell (RBC),  white blood cell (WBC), neutrophil and lymphocyte in treatments were influenced by the herbicide after 2 week and 3 week (P<0.05). The lowest RBC and the highest monocyte, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were observed in the treatment of fish exposed to sub-lethal concentration of herbicide after three week (P>0.05) The results of this study showed that sub-lethal toxicity of 2,4 D- MCPA herbicide after 2 week and 3 week with the reduction of white blood cells, neutrophil and lymphocytes could weaken the activity of the immune system of rainbow trout and increase the level of liver enzymes In blood serum, it also shows the damage caused by exposure to this toxin

High-density aquaculture has led to congestion and excessive stress and contributed to bacterial infection outbreaks that have caused high mortality. This experiment was conducted to evaluate the effect of dietary supplementation of astaxanthin on the growth performances, survival and several of innate immunity parameters of rainbow trout (Oncorhynchus mykiss) larvae for 60 days. In this experiment, 360 of larvae (with average weight of 0.13±0.01) in 4 treatments and 3 replicates (n=30 in each replicate) in a completely randomized design was divided and fed with diets containing 0, 50, 100 and 150 g astaxanthin /kg food respectively. The present results showed that diets containing astaxanthin showed a significant difference in growth, survival and innate immunity compared with control treatment (P<0.05). The highest FW, SGR, WG, PER, survival, total protein and globulin were observed in the diet containing 100 mg/kg astaxanthin which had a significant difference compared with other treatments (P<0.05). The highest lysozyme activity and albumin were observed in treatments containing 150 mg/kg astaxanthin which showed a significant difference compared with other treatments (P<0.05). Finally, the present results suggest that diets containing 100 and 150 g/kg dietary astaxanthin could improve growth, survival and innate immunity responses of rainbow trout.

Khalkai River is located in northern part of Iran that passes through Masal City and enters Anzali wetland. The effects of trout farm effluents on the water quality parameters and self-purification in the Khalkai River were investigated. In this study, four trout farms and eight stations (inlet and outlet of each farm) were selected. Physiochemical characteristics and nutrients of water, including water temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), biological oxygen demand (BOD5), Chemical Oxygen Demand (COD), phosphate, nitrate and nitrite were monitored monthly in five month. The results showed that the average of these parameters from entrance stations were: 10.09±0.62 mg/lit for DO, 6.62±2.16 mg/lit for BOD5, 0.048 ±0.005 mg/lit for PO4, and 0.035 ±0.004 mg/lit for NO2. Also outlet station were calculated between, 9.20±0.73 for DO, 12.81±3.97 mg/lit for BOD5,, 0.075±0.007 mg/lit for PO4, and 0.088±0.009 mg/lit for NO2, respectively. All the parameters showed fluctuations at different stations, and for some of them such as BOD5, COD and phosphate, nitrate and nitrite there was significant difference between before and after farm stations (p<0.05). The parameters showed fluctuations at different stations, and for some of them such as BOD5, COD, TDS, EC, phosphate, and nitrite there was significant difference between different month (p<0.05). These results were due to the effects of trout farms and of the self-purification of river. Meanwhile, all the parameters showed changes in different seasons that were due to fluctuations of environmental conditions and activity rates of the farms.

To investigate the effect of probioenzyme on growth, nutrition, hematology and immune response in rainbow trout (Oncorhynchus mykiss),this matter was supplemented at 0.3, and 0.5g/kg diet(treatments of 2 and 3 respectively) and control group(treatment 1: no food supplemented probioenzyme) in three treatments with three replications. This survey was performed in nine 200ltanks containing 30  fish(average weight: 26.3± 2.7g) in each tank for 60 days. At the end of the feeding period, the growth and blood factors analyzed. Based on the results, there is no significant difference between treatments 1, 2 and in growth, nutrition and blood erythrocytes factors(P >0.05). The mean white blood cells and blood cells neutrophil percentage in treatment of 3 was significantly different (P <0.05) from the control group fish. Significant differences in serum complement components in the treated groups were in comparission to control group (P <0.05). ACH50 activity and immunoglobulin (IgM) did not show significant differences between treatments (P> 0.05). The lysozyme and serum globulins in treatment 3 compared to the control treatment was higher and statistically significant (P <0.05). Although there weren,t signs of significant effects of probioenzyme on growth and nutrition factors, Probioenzyme can have immunological effects on rainbow trout.

This study was performed to compare the effects of enriched Artemia urmiana with inland made oil (SELCO) with commercial SELCO on new feeding larvae of rainbow trout. This study was conducted on fishes with 0.1 ± 0.002 g weights in 3 gropes and 3 replicates during a 30 – day period. The fish larvae were collected randomly from trout culture ponds. Treatments included: 1- Artemia nauplii enriched with SELCO- made in country 2- unenriched Artemia nauplii 3- Artemia nauplii enriched with commercial SELCO. The results showed that larvae of treatments 1&3 grew faster than treatment 2. Also , the same treatment produced heavier larvae than treatments 1 and 3 ( p

This study was aimed to evaluate the impact of Nano Zn as dietary zinc source on hematological parameters of rainbow trout including red blood cell (RBC) count and indices. Total number of 900 rainbow trout (17.22±5.41 g) fingerlings were randomly distributed in triplicates among six treatments and adapted to the farm conditions for 2 days. The basal diet were contained no amount of zinc supplementation and considered as the control treatment. The experimental diets were prepared by adding 10, 30, 50 and 70 mg of Nano zinc (40-60 nm diameters) and 70 mg zinc sulfate per each kg of basal diet. The fish specimens were fed for 8 weeks with the relevant diet of each treatment and their erythrocyte properties were consider at the end of experiment. The results showed that fish in the 50 mg kg-1 Nano ZnO treatment had the maximum of hemoglobin, hematocrit, mean corpuscular hemoglobin (MCH) compared to other treatments. The largest numbers of RBCs followed by the mean corpuscular hemoglobin concentration (MCHC) were also found in the 30 mg kg-1 Nano ZnO treatment, although showed no significant difference with the 50 mg kg-1 Nano ZnO treatment. Findings of the current study indicated that erythrocyte indices of rainbow trout fingerlings could be improved by the Nano Zn supplementation as a new form of physical structure of metal elements.

This study aims to evaluate and comparison of the accumulation of heavy metals Fe, Cu and Co in fish eggs, muscle of fingerling, fish market and male and female breeding stock farmed Oncorhynchus mykiss from Lorestan province in 2011. 75 samples by fish eggs, fingerling, fish market and male and female breeding stock were prepared from three ponds breeding center Ghezel rood of Brojerd, Lorestan province. The concentrations of heavy metals were measured by atomic absorption Perkin Elmer 4100. Data analysis was performed with the software SPSS18 and to ANOVA one way. Concentration of Fe, Cu and Co in fish egg of Oncorhynchus mykiss were 0.523±0.061, 0.733±0.152 and 0.23±0.05 mg/Kg (P<0.05). The highest and lowest of accumulation of Fe obtained in liver of female breeding stock (7.35±0.75 mg/kg) and muscle of fingerling (0.39±0.015 mg/Kg). The highest and lowest of accumulation of Cu was in liver of female breeding stock (4.33±0.83 mg/kg) and muscle of fish market (0.53±0.15 mg/Kg). The highest and lowest of accumulation of Co was in gill of female breeding stock (4.26±0.8355 mg/kg) and fish egg (0.23±0.05 mg/Kg).

The aim of this trial was to evaluate the effect of gamma radiation on growth and hematological parameters of rainbow trout (Oncorhynchus mykiss) larvae. In this research, Rainbow trout of eggs were irradiated by low (1, 2.5, 5Gy) and high doses (10, 20, 40 Gy) of gamma radiation. After 90 days, the growth and survival eggs and blood parameters of larvae was investigated. The result showed the negative effects of a gamma ray, as the increase in levels of radiation caused a significant decrease in the growth and survival of all treatments. Eggs exposed dose 40 Gy of gamma radiation, destroyed. The highest rates of growth and survival obtained in the control treatment and increased radiation levels, brought about significantly decreased on mentioned parameters. A decreasing trend in blood parameters was observed when the radiation levels increased. In all treatments, levels of RBC (red blood cells), Hct (hematocrit) and Hb (hemoglobin) declined significantly (P<0.05) as the irradiation levels increased, where as the amount of MCV (Mean corpuscular Volume) and MCH (Mean corpuscular hemoglobin) not changed. Also the levels of white blood cells (WBC), lymphocytes and monocytes, decreased, that this reduction was not significant (P<0.05). The results suggest that gamma rays can be a potential candidate for damage cells, resulting in decreased of growth and survival of eggs and larvae of hematology of rainbow trout.

The present study was performed to elucidate the probable effects of prebiotic Mannan Oligosaccharides supplementation in diets on growth performance and feed efficiency of rainbow trout fry. 1500 fish with average weight of 110±10 mg were distributed into 12 (35 L) tanks (125 fish/tank) and cultured for 60 days using experimental diets. Fish diet was used by prebiotic supplementation at three levels of 0.5, 1, and 2 g/kg along with a control diet. The results showed that final weight significantly increased in fish fed 0.5, 1 and 2 g/kg (Final weight: 2.03±0.11, 2.61±0.69 and 2.57±0.04 gr, respectively) Mannan prebiotic supplementation were significantly higher than the control group (Final weight: 1.67±0.05 gr). However, feed conversion ratio in fish fed 0.5, 1 and 2 g/kg Mannan prebiotic supplementation were significantly lower than the control group (P<0.05). The use of 1g/kg dietary Mannan Oligosaccharides prebiotic improved the growth parameter and feed efficiency ratio in rainbow trout fry.