saltanat najjar lashgari

Caspian trout, Salmo caspius, Kessler 1877 is an anadromous form of brown trout. In vertebrates, the functional receptors of THs, including thyroid hormone receptors (TRs) (thrα, thrβ). In developing fish eggs, the expression of THRs has been reported in different time periods. The ontogeny of the thrβ in the eggs of Caspian trout (Salmo caspius) has been investigated in the present study. The sampling of ova was done before and post fertilization, 24 and 48 h post fertilization, eyeing stage, hatching and CYA while being exposed for 1 h to various thyroxin hormone concentrations including 0 (control, without hormone), 0.25, 0.5and 0.75 mgL-1. The statistical analysis showed increased gene expression of thrβ during the development period. An inverse relationship between hormone concentration with eyeing and hatching percentage were detected in the eggs. In summary using thyroxin hormone by applied doses to achieve better fertilization efficiency not recommended.

In this study, the sperm quality indicators of rainbow trout breeders in selected Specific Pathogen Free (SPF) farms of the country were investigated in order to plan the long-term preservation of rainbow trout sperm through cryopreservation and creating a sperm bank in the next phase. Sperm samples from 24 breeders from six selected SPF farms from West-Azerbaijan and Mazandaran provinces were collected and evaluated. The average density of sperm is 7.83 ± 4 billion per milliliter, the average volume of extracted sperm is 9.2 ± 1.6 ml, the average percentage of motility and its duration were 78.7 ± 10.3% and 26.6 ± 4.4 seconds, the average pH was 7.74 ± 0.23 and the fertilization percentage of the samples was as 92.8 ± 1.2%. The results showed that the pH 7.7-7.8 is the most appropriate value for inducing motility and its increasing or decreasing relative to this value causes a decrease in fertilization efficiency. Also, a positive correlation between pH and sperm motility (r = 0.533) and fertility (r = 0.67) was determined. According to the obtained information, the characteristics of the best sperm sample is selected for long-term storage and the creation of a genetically diverse sperm bank and targeted management of rainbow trout reproduction.

It is very important and necessary to choose the appropriate cold water fish species and check their growth performance in cage fish farming in the Caspian Sea. The results showed that the rainbow trout in Kiashahr region reached an average of 98.3±19.8 to 1149.8±203.5 grams in a period of 4.5 months. Also, although the breeding of salmon from the initial weight of about 100 grams was suitable, but considering the temperature limits for this fish in the Caspian Sea, the introduction of higher weights can reduce the length of the breeding period. Caspian Sea salmon reached in Jaffroud region from the average weight of 120.14±1.98 to 632.5±82.08 grams in a period of 4.5 months from January to May, and in Anzali free zone from 212.7 ± 15.28 to 508.81 ± 76.54 grams in a period of 2 months from January to March in floating cages, which shows the favorable growth of this fish in this region.

Considering the importance of evaluating genetic diversity and population structure in managing and selecting the most efficient breeders for reproduction, genetic diversity of rainbow trout (Oncorhynchus mykiss) pre-breeders in selected farms of West Azerbaijan province (farms 1, 2 and 3) was studied using seven pairs of microsatellite primers. For this purpose, 50 pre-breeders of each field were sampled and genomic DNA was extracted using ammonium acetate method. To observe the alleles and determine their size were used vertical electrophoresis of 6% polyacrylamide gel and silver nitrate staining. Relevant calculations were performed using Excel, INTAS GEL DOC and PopGene software. Based on the results, the highest number of real alleles (7.71) and the amount of observed heterozygosity (0.46±0.12) was observed in farm fish of No. 3 and the lowest number of real alleles (5.29±0.01) and the amount observed heterozygosity (0.34±0.08) was observed in farm fish No. 2. The highest genetic distance (0.07) and the lowest genetic similarity (0.93) were calculated between farm fish No. 3 & 1 and the lowest genetic distance (0.02) and the highest genetic similarity (0.98) were calculated between farm fish No. 2 & 1 were calculated. The highest amount of genetic differentiation (0.077) was obtained between farm fish No. 3 & 1 and the lowest amount (0.034) was obtained between farm fish No. 2 & 1. The results of molecular analysis of variance indicate the existence of significant genetic diversity differences between the fish of the studied farms (p<0.001). The results of FST test showed that the genetic differentiation between the breeding populations in this study is moderate and was evident the shift of breeders between different populations in the recent past or the use of a reference population and breeders with similar gene storage in propagation season among the studied farms. The findings of this study suggest that high mixing of populations with each other and factors such as selection and current policies of each farm may have led to a reduction in genetic diversity and differentiation between populations. The results of this study can be used to manage breeding stocks and breeding programs of this important commercial species.

This study was conducted from April 2017 to June 2018 in a Trout aquaculture farm in Firoozkoh, Tehran province, to distinguish environmental and managerial risk factors affecting incidence of viral diseases in the fish farm under study. Averaged visit from fish farm was 2 times a month and all biosecurity measures were advised and applied during every visit. Some of the physico-chemical parameters were recorded daily. Samples from all cargoes of eyed-eggs imported from abroad and also from larvae after active swimming and absorption of yolk sac were taken for RT-PCR test. Virology, bacteriology, parasitology and mycology tests in the farm and authorized laboratory were done. Clinical observations, macroscopic and microscopic examinations, checking all the sanitarian and productional managerial factors, also checking all the physical and chemical factors affecting the outbreak of viral diseases were done. During clinical observation of fishes, these symptoms were observed; anorexia, gathering at the raceway’s side and outlet, cachexia, one and two side exophthalmia, melanosis, integument ulcers, hemorrhage in ventricular and ocular areas, petechia in ventricular area, fecal casts, high mortality and also presence of a large number of moribund fishes. The result of the laboratory examinations was IHN positive of Rainbow trout fries. This disease caused about 80% mortality of the fries produced from the imported eyed-eggs cargo. The other fatalities with different reasons were also recorded such as; the Lutra’s attack at nights, the farm’s personnel running amongst other farms and transferrin pathogens, the transportation vehicles not being proper disinfected while inter to and exit from the farm and the severe food intoxication of fries. Regarding the results of this study, instruction of scientific and practical models has presented to decrease the effect of environmental and managerial risk factors in the incidence of the disease.

The present study aimed to investigate the effect of the commercial probiotic BetaPlus® Ultra (BP Ultra) in combination with the galacto-oligosaccharide (GOS) or the isomalto-oligosaccharide (IMO) prebiotics in Caspian trout (Salmo caspius) parr. S. caspius (8.5±0.07 g) was randomly distributed in three dietary treatments including: control group, synbiotic treatment I (0.1% BP Ultra + 0.2% GOS) and synbiotic treatment II (0.1% BP Ultra + 0.2% IMO) and in nine 300 L circular polyethylene tanks with three replications per treatment and, then, fed for seven weeks. At the end of this experiment, growth performance and hepatosomatic index improved significantly in both synbiotic treatments compared to the control group (p<0.05). However, the trend of this improvement was more noticeable in the synbiotic treatment I compared to the synbiotic treatment II without any significant difference (p>0.05). The counts of red and white blood cells in the both synbiotic treatments were significantly decreased and increased compared to the control group, respectively (P<0.05). The values of hemoglobin, packed cell volume, and mean corpuscular hemoglobin in the synbiotic treatment I showed significant increases compared to the synbiotic treatment II (P<0.05). The highest significant levels of crude protein and lipid in carcass were observed in the synbiotic treatment II and the synbiotic treatment I, respectively (P<0.05). Dry matter of carcass was increased significantly in the synbiotic treatment I compared to the synbiotic treatment II (P<0.05). The lowest ash content of carcass was observed in the synbiotic treatment I with a significant difference compared to the synbiotic treatment II and the control group (P<0.05). The results of the present study demonstrated the remarkable efficiency of the synbiotic treatment II on the protein increase and lipid reduction in carcass, although the synbiotic treatment I had a better effect on growth performance and hematological parameters in S. caspius.

The aim of this study was to monitor and evaluate the environmental and directory risk factors affecting the occurrence of some specific viral diseases in the region in the region of establishing a large-scale project of rainbow trout production of specific pathogens free (SPF) in the country in order to achieve the guidelines for managing and reducing the risks assessed in the pre-quarantine hall and the SPF center. For this purpose, after completing the questionnaire of physical and chemical indicators of pre-quarantine water inlet and outlet such as oxygen, temperature, pH, nitrite, nitrate, ammonium, ammonia and total bacteria were measured for 6 months from May to October 2017 according to the standard method. Also fish in the pre-quarantine hall were sampled to check for the possibility of infection with IPN, IHN and VHS viruses. The results showed that the average temperature, soluble oxygen, pH, nitrite, nitrate, ammonium, ammonia and total count water of the pre-quarantine hall entrance were respectively 17±1.55°C, 8.32±0.65 mg/l, 8.98±0.37 mg/l, 0.003±0.000 mg/l, 3.10±0.71 mg/l, 0.09±0.10 mg/l, 0.08±0.09 mg/l and 90.50±86.58 colony units per ml and outlet water were respectively 17.59±1.46°C, 8.20±0.62 mg/l, 8.18±0.35 mg/l, 0.040±0.040 mg/l, 3.74±1.14 mg/l, 0.09±0.07 mg/l, 0.08±0.07 mg/l and 784.50±1329.95 colony units per ml. The findings of this study indicate that in the process of producing rainbow trout of Specific Pathogens Free (SPF) from pre-breeder to breeder stage in pre-quarantine hall, there has been avoidance the entry of pathogens. And fluctuations in the physical and chemical indicators of water during the breeding period, the lack of a central oxygen generator, problems with the aeration system and the low flow of incoming water were identified as risk factors.

The present study was aimed to evaluate the effect of different levels of choline chloride (ziro, 250, 500, 750, 1000, and 2000mg/kg food) on the growth performance, carcass compositions, and haematology of Caspian salmon (Salmo trutta caspius).

270 fish pieces weighing 8.82±0.38 in 18, 250‐liter fiberglass tanks (15 fish per tank) with 3 repetitions per treatment with one of six experimental diets (control diet, Cho250, Cho500, Cho750, Cho1000, and Cho2000) were fed for 10 weeks.

Final weight, weight gain, specific growth rate index, protein yield ratio, obesity ratio, and feed conversion ratio of fish fed with diet containing appropriate levels of choline (750 to 1000mg/kg choline), were significantly higher than the fish fed with control diet and Cho250 diet (p≤0.05). There was a significant decrease in the feed conversion ratio of Cho750 and Cho1000 treatments compared to control treatment. It can be acknowledged that the Caspian Sea salmon cannot meet the physiological needs of choline by biosynthesizing choline from the liver or methionine. By increasing choline in the diet, the amount of protein and fat in the carcass increased significantly, but the moisture content of the carcass decreased (p≤0.05). Also, moderate amounts of fatty liver fish fed with control treatment and Cho250 treatment were significantly lower than other treatments. The results showed a negative relationship between the increase in choline levels and the activity of hepatic blood enzymes (p≤0.05).

In order to increase the growth process, strengthen the immune system, and optimally combine the carcass, the most appropriate amount of choline chloride is 750‐1000mg/kg in the diet of Caspian Sea salmon.

The present study was designed and performed to evaluate the effects of various concentrations of folic acid and riboflavin on some growth, blood and immune indices of Rainbow trout (Oncorhynchus mykiss) fingerlings. For this purpose, 891 fingerling rainbow trout with the average weight of 6-7 g were distributed in 27 fiberglass tanks with 9 treatments randomly (33 fish in each tank). Rainbow trout fingerlings was fed with normal diet and diet containing various levels of folic acid (0, 6 and 10 mg) and riboflavin (0, 20 and 30 mg). At the end of the 60-day period of breeding, 30 fish from each treatment were selected randomly and blood sampling was performed after measuring the growth factors. The results showed that the highest mean body weight gain, specific growth factor, daily growth factor, white blood cells, red blood cells, hemoglobin and hematocrit were observed in fish fed diets containing 20 mg riboflavin and 10 mg folic acid and showed a significant difference with control group and other treatments (P<0.05). In terms of survival rate, there was no significant difference between treatments. Based on the results, the best formula for feeding rainbow trout fingerlings is a combination of 20 mg riboflavin and 10 mg folic acid per kilogram of dry food. Due to the low consumption of vitamins, the use of this formula is economical in cold water fish breeding farms and has economic justification.

The effect of marine oils has been proven in many diseases due to the presence of n-3 fatty acids. Most of the clinical effects of n-3 fatty acids are due to the presence of Docosahexaenoic acid (DHA( and Eicosapentaenoic acid (EPA), which has so far not been found in any other food, except in fish. The purpose of this study was to investigate the effects of different levels of fish oil and canola oil on diet, on growth, survival and body chemical composition of Fattening rainbow trout (Oncorhynchus mykiss) Which ultimately can compensate for the deficiency of n-3 fatty acids in the household food basket and it is an important step towards the health of the community. For this purpose, three experimental diets were prepared with the same protein level (40%) and different fat levels (the first diet with 10% fish oil, the second diet with 10% canola oil and the third diet with 5% fish oil and 5% canola oil) and each one with three repetitions and 270 rainbow trout with an average weight of 100±10 g were cultured with a density of 30 in per cage for 56 days. Based on the results, there were significant differences between mean weight, body weight gain, feed conversion ratio, specific growth rate and condition factor in all three treatments (P<0.05). However, there was no significant difference in terms of survival rate and body chemical composition between treatments (P>0.05). In general, the results showed that the third treatment (5% fish oil and 5% canola oil) in the diet improved the growth indices, survival rate and condition factor (P<0.05).

The majority of fungicides, including captan, used in gardens and farms are washed into the aquatic environments. These compounds can lead to extensive side effects on the inhabitants living in that exposed area. In this research, toxicity of captan on fingerling grass carps (3-5 g) was studied. Based on the results, captan was categorized as an acute toxin with LC5096h and MAC values of 0.9 and 0.09 mg/ml, respectively. This toxin damaged severely the gills and liver of fishes and the toxic severity increased in higher doses of the toxin. Furthermore, hematochemical studies showed significant drops in all red blood cell criteria, except for MCH (mean corpuscular haemoglobin) and MCV (mean corpuscular volume). Besides, captan decreased significantly the total immunoglobulin and white blood cell counts, except for monocytes and neutrophils. As a conclusion, captan causes detrimental effects on several tissues of Ctenopharyngodon idella, and therefore limited utilisation of this fungicide is recommended strongly.

Caspian brown trout (Salmo trutta caspius) is one of the nine subspecies of brown trout (Salmo trutta) in the world and is one of the economically important species and endangered in the Caspian Sea. In this study, the genetic diversity of the Caspian brown trout was investigated using microsatellite method. For this purpose, 225 specimens of adult Caspian brown trout were collected from Cheshmeh Killed and Kargan Rud rivers and genomic DNA was extracted using Ammonium Acetate method. The quality and quantity of the extracted DNA was assessed using a horizontal electrophoresis in 1% agarose gel and spectrophotometry methods. The Polymerase Chain Reaction (PCR) was performed using 16 pairs SSR primers and the amplified products were vertical electrophoresis using 6% polyacrylamide gel and were stained using silver nitrate method. DNA bands were scored using Photo- Capt software and produced five polymorphic loci. The mean observed and expected heterozygosity was calculated 0.47±0.09 and 0.61±0.10 respectively and more loci were out of Hardy- Weinberg equilibrium (P<0.001). Analysis of molecular variance (AMOVA) showed significant differences in genetic diversity between and within populations (P<0.01). So there is more than one population in studied rivers that should be considered in restructuring reserves.