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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.

Since shrimp white spot virus has infected shrimps of all ages and caused widespread loss of shrimps in Iran and across the world, and the pandemic has caused great loss for shrimp farmers, many studies have been carried outto this day in order to identify the reasons and the risk factors regarding this fact. Regarding the importance of the subject and also the different opinions on the results of the past researches, in this study, we have tried to carry out a retrospective review on past studies in Iran and other countries especially on the target tissues for shrimp white spot virus in order to specify the tendency of the white spot virus generally. In this survey, the accomplished studies and researches in the Shrimp Research Center (Bushehr Province), other research centers, universities and higher education centers in Iran and other countries, were collected and the studies carried out on hepatopancreas, intestine, gill and other tissues were examined. Most of the target tissues for white spot virus in Penaeus vannameiwith high intensity are; hemolymph, posterior intestine epithelial cells and cephalothorax epidermis.Some researchers have claimed that the epithelium tissue is the most targeted tissue for white spot virus in penaeus vannamei. The lowest mean values of severity index (SI) were found to be from hemolymph, posterior intestine epithelial cells and cephalothorax epidermis. This could be due to more contact surface of the epidermis with the virus and also more receivers for the virus or lower operation of the immune system especially in horizontal transmission.It seems that hemolymph is the most probable early target tissue for the virus in vertical transmission because the virus replication is at a higher level compared to the other tissues.The most of researchers have pointed out in their researches that tissue of gill, stomach, hepatopancreas and intestine of shrimp are the most important tissues in relation to the white spot virus infection.

leaping mullet is one of the valuable and economic species that accounts for a significant part of the bony fish catch in the Caspian Sea every year. In this study, prevalence and intensity of parasitic infections were investigated as one of the possible reasons for the decrease in stocks and the amount of catch of this fish. A hundred and fifty nine leaping mullets were sampled from Feb 2021 to April 2022 on the southwestern coasts of the Caspian Sea. Wet mounts were prepared from gills, skin and fins and monogenean parasites were fixed by glyceirn gelly. In order to investigate the digistive parasites, the contents of digestive tract after dilution were examined with a light microscope. Identification of parasites was done after photographing, drawing and measuring different organs and comparing with identification keys.  In all, 6 species of parasites, including two monogenean species, Ligophorus szidati and Solostamenides mugilis, three species of terematodes, Saccocoelium obesum, Saccocoelium tensum and Diplostomum spathaceum, and one protozoan species, Trichodina sp. were isolated and identified. Based on the results, S.obesum with 51.29% prevalence index was the most dominant parasite in the intestines of these fish. In this study, two monogenean species, Solostamenides mugilis and Ligophorus szidati, were reported for the first time from leaping mullet in the Caspian Sea. In general, the parasitological examination of mullet fish showed that the prevalence and intensity of parasitic infections in them is very limited. Therefore, the current situation of parasitic infections is not considered a threat to leaping mullet fish health.

In this research, 30 farms from five cities of Markazi province were assessed and biosecurity audited. The forms for examining danger crossings, mechanization equipment used on the farm, and biosecurity audit (standard of the country's veterinary organization) were completed for each farm. The relationship between mechanization and the level of biosecurity was done using correlation analysis and a semi-quantitative model was used to assess the probability of risk. The obtained results showed the maximum probability of risk with a numerical index of 0.40 for the trout farms of Arak and Farahan and the maximum mean probability of risk (± standard error) with 0.205±0.022 in Farahan city and the minimum probability of risk with a numerical index of 0.03 for Arak and Shazand, the mean of risk probability (± standard error) was obtained with 0.15±0.016 in the trout rearing farms in Shazand. The mean probability of risk at the level of all the selected farms of certain studied cities of Markazi province was calculated as 18.009 ± 0.009, which indicated that all the selected farms studied were in the category of medium possible risk (level B). In order to test the relationship between two variables, the probability of risk and the degree of mechanization from Pearson's correlation test were used. No significant correlation was observed between the probability of risk and the degree of mechanization (P = 0.41, n = 30, and r = 34). As a result, from the statistical point of view, it was determined that the variables of risk probability and the degree of mechanization were not related to each other. This component was also similar for production capacity and mechanization level. The obtained results showed that due to the weakness of biosecurity equipment in the mechanization of dual-purposed agricultural farms for fish farming in the Markazi province, the risk in some of these farms has increased to the level of being placed at probability of high risk (level C), which can easily reduce the risk in these farms significantly by taking necessary measures and establishing biosecurity plans.

According to statistical reports of FAO in 2018, Iran has been one of the most important producers of rainbow trout with producing 180,000 tons. Meanwhile, Iran has a semi-arid and arid climate and is facing to decrease of fresh water resources and this is a big problem in the production of rainbow trout using fresh water. Therefore, it is vital to pay attention to other water resources for aquaculture. In this regard, the cultivation of trout in floating cages in the Caspian Sea is one of the main options for the development of this industry and increase the production of salmon in the country and on a global scale. Cage culture is a new method of aquaculture that has developed a lot in the last half century, but unfortunately our country has little experience in this field. One of the requirements for the development of fish cage culture is the awareness of possible diseases and their health risks. Due to the novelty of this type of breeding system in Iran and its different breeding and health management compared to fresh water, there is an urgent need to introduce industry-specific health regulations and strategies to control and prevent potential risks and economic losses. The aim of this study was introduce effective breeding management factors in maintaining health and preventing the death of rainbow trout after introduction to cages for sustainable production of these fish in floating cages in the Caspian Sea.

In the present study, the effects of different probiotics mixtures on growth performance, hematology and antioxidant capacity of Asian seabass (Lates calcarifer) juveniles (30 g). In this study, three bacterial mixtures were used that were isolated from the native aquatic species of Khuzestan and the South of the country, which include: the first group includes different strains of Lactobacillus plantarum, the second group includes L. plantarum with a mixture of L. bulgaricus, L. acidophilus and L. rahamnosus and the third group includes the mixture of bacteria of the first and second groups along with the mixture of Bacillus cereus and B. thuringiensis, which were identified through their quorum quenching features and isolated from Asian sea bass. Four treatments were designed by spraying various bacterial mixture on a basal diet, which included diet (1, control group) on which only sterile physiological serum was sprayed on the diet, diet (2) on which the bacterial mixture of the first group was sprayed on the diet, diet (3) on which the mixture of bacteria of the second group was sprayed and diet (4) which was the mixture of all bacteria was sprayed on it and fed to the fish. The fish was fed with the experimental diets four times a day up to satiation at 30.5 °C for 100 days. In this study, the fish that was fed with 2, 3 and 4 diets had a higher growth performance than the control (p < 0.05), which was associated with an improvement in the food conversion ratio. Blood and antioxidant indices were improved in the fish fed with diets containing probiotics mixture. Treatment 4 had more total plasma protein and albumin than other treatments. In conclusion, the use of a mixture of different probiotics increased growth in Asian seabass that associated with improved health indices in this species.

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.

The aim of the present study is to investigate the growth performance and sexual maturation process of female rainbow trout reared in a cage in the Caspian Sea (Mazandaran- Nowshahr). Rainbow trout with an average weight of 122± 5 g were stocked into a cage located in Caspian Sea. Fish were fed daily and random sampling was done monthly (January 2015) to May 2016. Weight and length of thirty fish were measured; their gonad and liver were weighted; total length, total weight, liver and gonad weight, condition factor, GSI and HSI and oocyte diameter were calculated; their blood samples were collected and the levels of 17 beta estradiol, testosterone, progesterone and the vitellogenin were measured; also gonad tissue samples were prepared and examined using a light microscope. The results showed optimal somatic and gonadal growth of fish caged in the Caspian Sea. Sex hormones and vitellogenin levels increased significantly (P<0.01) during the study period. The levels of 17 beta estradiol, testosterone and progesterone in January were 0.56± 0.05 ngml-1, 0.50± 0.05 ngml-1and 0.14± 0.01 ngml-1 respectively and reach to 1.63± 0.13 ngml-1, 0.80± 0.01 ngml-1 and 0.28± 0.03 ngml-1 in May, respectively. Vitellogenin levels increased from 382.40± 55.26 ngml-1 in January to 651.40± 86.34 ngml-1 in May. The gonads developed to stage 4 and the oocyte diameter increased significantly (P<0.01) during the study period. The findings of present study show that female rainbow trout are able to have appropriate somatic growth in the brackish water of the Caspian Sea like fresh water, and the natural process of sexual maturation won’t be disturbed.

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.

Saprolegnia genus and its species have been recognized as one of the most important fungal causes of egg loss in freshwater hatcheries around the world. Although malachite green has a good antifungal effect in controlling egg loss due to saprolgniasis in hatcheries, it has been banned because of its carcinogenic and toxic effects. Various studies have been carried out to identify suitable compounds that can replace malachite green at the farms. The purpose of this study was to evaluate the antifungal effects of Huwa- San TR- 50 in vitro based on its MIC (Minimum Inhibitory Concentration) in comparison with green malachite on saproligenia specimens isolated from rainbow trout (Oncorhynchus mykiss) and Persion sturgeon (Acipencer persicus) hatcheries. The doses of 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1200, 1400, 1600 and 1800 ppm were used for MIC experiments. Based on the results, the MIC doses were determined for saprolgenia isolated from Persion sturgeon and rainbow trout 1400 ppm and  800 ppm respectively. Based on the results, it seems that Huwa- San TR- 50 could be used as a suitable antifungal agent for the control of saprolegniasis in fish hatcheries but it should be kept in mind that the resistance of different saproligenia specimens to this drug composition may differ. This is because the ability to control fungi in hatchery is not fully successful when using antifungal compounds other than malachite green.

In this study has been attempted to evaluate some hematological, serological and immunological indices to determine the baseline for determining the health of SPF brood stock. For this purpose, during three sampling stages, before, simultaneously and after breeding time, the blood samples were collected from brood stock fish at the SPF center in the Cold water fisheries research Center (Tonekabon) and two elected farms (F and S). The fish of SPF center were supplied of the two others farms (F and S) and sampling were conducted from same folk at the SPF center and elected farms. Hematocrit, hemoglobin, total protein, albumin, alanine aminotransferase (ALT), aspartate amino transferees (AST), certain phosphokinase (CPK), alkaline phosphatase (ALP), total IgM and lysozyme were measured. The results showed that before the breeding season, the levels of hemoglobin, ALT and total IgM were not significantly different among the fish in the three centers, but the lysozyme levels of SPF center were significantly and numerically higher than S and F fish farms respectively. Statistical analysis of data showed that there were no significant differences in hematocrit, hemoglobin, total protein, albumin, IgM, AST, ALT and lysozyme levels among the three groups during the breeding season. The results after the breeding season showed that the hematocrit and weight of SPF fish were significantly higher than those two other groups but  hemoglobin, IgM and lysozyme levels were significantly and or numerically higher than those two other groups. Based on the results, it seems that the use of blood and serum indices can be used as a tool for health assessment condition, nutrition, rearing and hygiene managements. It seems that the health and nutrition management of the SPF center had been better than two other farms and it caused to improve the hemato- serological and immunological parameters of the SPF fish in compared to the other elected farms fish after breeding time.

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.

This research was conducted in autumn and winter of 2016 in Shahid Motahary Coldwater Fishes Genetic and Breeding Research Center. The purpose of this study was to evaluate the effect of Huwa-San TR-50 solution on controlling rainbow trout fungus contamination at incubation stage and comparing its effects with malachite green and formalin. To do this, 27 Californian traphs were used in 9 treatments and 3 replicates, and 700 eggs of rainbow trout were stoked  in each traph. 5 treatments with different concentrations (50, 100, 200, 300 and 500 ppm) of Huwa-San TR-50 solution, one treatment with malachite green (2ppm) and one treatment with formalin (1000ppm), by bathing for 30 minutes were disinfected; a positive control (contaminated with fungi and without medication) and a negative control (non-infected with fungi and without medication) were also considered. The results showed that solution of 300 ppm Huwa-San TR-50 was suitable concentration for disinfection of eggs. Percentage of eyed egg and hatching at higher doses and lower than 300 ppm Huwa-San TR-50 showed a decreasing trend.

Saprolegnia sp. is the most important pathogenic fungi in fish. Saprolegnia parasitica, S. diclina, S. ferax and S. hypogina are the most abundance of the fungi that caused saprolegniasis in fish and hatcheries. They have global distributions and their presences were reported from fresh water fish farms of the world. Up till 2002, Saprolegnia infections in aquaculture were kept under control with malachite green. However, the use of malachite green has been banned worldwide due to its carcinogenic and toxicological effects and this has resulted in a dramatic re-emergence of Saprolegnia infections in aquaculture. Many investigations have been carried out on the introduction of an appropriate anti-fungal agent alternative to malachite green. Huwa- San TR- 50 is a disinfectant based on hydrogen peroxide. One liter of Huwa-San TR-50 contains 570 g hydrogen peroxide and 0.36 g silver as stabilizer. In this study, the antifungal effects, minimum lethal concentration (MLC) and minimum inhibitory concentration (MIC) of Huwa- San TR- 50 were conducted and compared to malachite green in vivo several doses including the 0, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 ppm on the isolates saprolegnia sp were isolated from Rainbow trout. The results of MIC and MLC levels on the saprolegnia sp isolate from rainbow trout eggs were 400 and 800 ppm respectively. The results suggest that Huwa- San TR- 50 could introduce as appropriate anti-fungal agent alternative to malachite green.

In this study 180 beluga(Huso huso) weighted 120 ± 10gr with stocking density of 12 fish/tank ,after adaptation with synthetic diet , fed different levels of AFB1(0,25,50,75 & 100ppb/kg of diets) under controlled conditions(T=18±2ºC,DO=7.3ppm). The fish were fed 3% of body weight four times a day for 120 days.Record of physical and chemichal water caracters include : DO , temprature , pH , did weekly . Residue of AFB1 in muscls in different exprements determined by HPLC method . The amount of AFB1 in mscle was between 0.36 -2.90 ppb .Based on international standards these amount is not harmfull for human consumption.