علیرضا قائدی

Ornamental fish are classified as high value and low volume products. At each stage of the ornamental fish supply chain, fish are potentially exposed to stressors that can be detrimental to their welfare. During packaging, transport and adaptation, fish can experience high stress and their welfare can be compromised, leading to reduced safety and high mortality. Meanwhile, the transportation of live fish is known as the main cause of stress. It is estimated to be less than 5% for freshwater fish and up to 80% for wild-caught marine fish. One of the problems facing ornamental fish trade regulations is the difficulty in monitoring the welfare of ornamental fish. Rules have been defined for fish welfare in food fish aquaculture and for research processes, but few rules exist for the welfare of domestic and ornamental fish. Indicators for determining well-being can be divided into two categories: behavioral and non-behavioral. For example, the physiological effects of high stocking density in ornamental fish can lead to reduced water quality and increased aggressive behavior, while in some other species, low stocking can lead to increased territoriality and increased aggressive behavior by the dominant fish, causing damage to weak ones. For this reason, it is necessary to understand the behavioral compatibility of different species of ornamental fish. Also, changes in water quality between each stage of trade can expose the fish to considerable stress. One of the reasons for the difficulty of creating operational welfare indicators (OWI) for ornamental fish is the impact of the morphology of these fish on natural and swimming behaviors, which in some species is due to genetic manipulations and etc. in fish with big eyes, unnaturally long fins and bubbles. Another indicator of determining welfare is the use of observations of physical injuries, which in combination with behavior can be used to evaluate the welfare of ornamental fish. Using the behavioral and non-behavioral indicators presented in this article, a suitable OWI can be defined for different species of ornamental fish. To begin with, general indicators can be defined for larger categories (freshwater or saltwater fish, carnivores or herbivores, ...), and gradually OWIs can be defined in more detail.

Ensuring food and nutritional security is a top issue for global food-producing sectors among the projections of a 60% increase in food consumption by 2050 due to population growth. To address this challenge sustainably, the food and feed industry must conserve resources while feeding a growing population (Saiprasad et al., 2023a). This rapid expansion of aquaculture has led to increased demand for protein sources for feed production (Wang et al., 2023) and straining the supply of natural protein ingredients, such as fishmeal and plant protein sources. As a necessary way to reduce protein inclusion levels in aquaculture feed, lipids and carbohydrates are extensively used. Lipids can serve as an energy source with high energy density, and fish has good lipid absorption and utilization ability. Carbohydrate is a cheaper energy source than lipids and protein, which also serves as a swelling and stabilizer agent in fish feed (Kamalam et al., 2017). However, numerous studies have demonstrated that long-time ingestion of a high lipid/carbohydrate diet causes disturbance of lipid metabolism, excessive hepatic lipid accumulation, and mitochondria stress, thus inducing fatty liver disease and affecting the physiological condition and growth of fish (Ding et al., 2020; Jin et al., 2019a; Jin et al., 2020; Lin et al., 2018; Wang et al., 2021; Wang et al., 2020). Using functional feed additives is an effective way to relieve hepatic metabolic stress and improve fish health which has drawn considerable attention in the aquaculture nutrition field. Up to now, L-carnitine (Jin et al., 2019a), choline (Jin et al., 2019b), herb extract (He et al., 2021; Liu et al., 2021; Wang et al., 2021), and other feed additives showed positive effects on fish metabolic disorder. Bile acids (BAs) play important roles in lipid metabolism. They are synthesized from cholesterol exclusively by the liver. In the intestine, BAs act as detergents to emulsify and facilitate the absorption of dietary fats and lipid-soluble vitamins. Therefore, the objective of this study was to evaluate the effects of dietary BA supplementations on growth performance, carcass biochemical composition and Biochemical Factors of rainbow trout (Oncorhynchus mykiss).

A 75- day feeding experiment was conducted to investigate the effects of dietary bile acids (BAs, Roneon 30%) on nutritional index, growth, carcass biochemical composition, Biochemical Factors and economic return coefficient of rainbow trout (Oncorhynchus mykiss). An experiment was designed with four treatments each with three replicates. Experimental diets were made by supplementing a control diet (BA0) with 300, 600 and 900 mg bile acid (BA) kg− 1 diet, respectively. 600 juvenile rainbow trout average initial weight of 52±5 g (±SD) were assigned to twelve 2000 L experimental tanks. Fish were sampled on day 75 and growth performance indices including Food conversion ratio (FCR), Protein efficiency ratio (PER), Specific growth rate (SGR), Condition factor (CF), and Weight gain percentage (WGP) were compared among the treatments. Also carcass composition (protein, fat, ash, moisture) and bichemical factors of serum including Aspartate transaminase enzyme (AST), Alanine transaminase enzyme (ALT), Alkaline phosphatase enzyme (ALP), Lactate Dehydrogenase, Glucose, Triglyceride, Albumin and total protein were analyzed.

At the end of the experiment food conversion ratio, (<1) in the treatment of 900 mg/kg showed the best performance among the experimental treatments. The final weight (187.33±7.28 g) had a significant difference compared to other treatments(P<0.05). Specific growth rate, Condition factor, Protein efficiency ratio and Weight gain percentage were improved in fish fed with diets 600 and 900 mg/kg bile acid supplementation compered with other treatments. Also Treatments receiving bile acid supplementation had more crude protein and less ash than the control treatment and the 300 and 600 mg treatments had higher moisture content than other treatments (P<0.05). Glucose, Triglyceride, Albumin and Lactate Dehydrogenase did not change by the addition of bile acid supplementation (P>0.05). Cholesterol content was significantly higher in fish fed diet containing 900 mg/kg bile acid supplementation compared with control group (P< 0.05). Aspartate transaminase enzyme in the treatment of 900 mg/kg compared to the control group and 300 mg/kg, Alanine transaminase enzyme in the treatment of 900 mg/kg and Alkaline phosphatase enzyme in the treatment of 300 mg/kg compared to other treatments showed significant differences (P<0.05) (Tables 1- 3).Different lowercase letters in the same row indicate statistically significant differences (P<0.05).

Discussion and conclusion :

The changes of serum biochemical factors as well as the relative improvement of growth and nutrition factors indicated the positive performance of using 900 mg/kg bile acid supplementation in the diet of juvenile rainbow trout, while the effects of increasing Liver enzymes, the Serum Biochemical Factors in the mentioned treatment should be studied and investigated. Bile acid supplementation could also enhance crude protein and decrease of ash and moisture in treatment of 900 mg/kg while bile type, level and fish species must be considered. This study discusses these aspects in regard to fish nutrition to help increase the inclusion of dietary fishmeal alternatives and thus enhance aquaculture sustainability.

Aquaculture industry plays a considerable role in food security and white protein production in the world and Iran, too. Agriculture industry uses fresh or brackish water wells and springs in Iran's climate condition and especially in central and desert areas; therefore, it is recommended to use these scattered and small-scale water resources for aquaculture before using them in agriculture. Rainbow trout and common carp, as non-native species, have been used in the inland aquaculture industry for the last few years. But, based on their culture limitations and the significance of introducing some species with more economical efficiency for developing in Iran aquaculture industry, tilapia was introduced to Iran in 2008 and subjected to the primary researches including EIA (environmental impact assessment), reproducing and culturing technical knowledges, nutrition and all male production, then Tilapia culture developed these last years with companies’ investments in 5 provinces.Despite a lot of beneficial and recommendations for tilapia consumption for people and especially those who need high protein low lipid sources, there have been some limitations in its developing strategies because of using hormones, the ratio of omega 6 and 3, invasive effects, and culturing in wastewater. In this way, this study tried to document and respond to some significant questions and disasters in the developing tilapia culture industry. According to this study, tilapia consumption, as a high protein resource that is full of selenium and carotenoids, is recommended. Based on Iran’s agricultural development plan, importance of food security and available water resources, tilapia is a good species for introducing to Iran inland aquaculture industry in central regions with biofloc technology or recirculating system.

In an introduction to various types of tilapias, dietary requirements, and breeding methods, we become acquainted with a group of freshwater fish known as tilapia. These fish are cultivated worldwide due to their diverse characteristics. Different types of tilapias have distinct environmental conditions, dietary needs, and breeding methods. The dietary requirements of tilapia include protein, fats, and vitamins such as vitamin C and D, which can be sourced from various means. Breeding methods for tilapia encompass various environments, including freshwater ponds, lakes, and recirculating water systems. In each method, precise water condition management, proper nutrition, and disease control are of paramount importance. Overall, familiarizing oneself with the different types of tilapias and the principles of their cultivation is crucial as a valuable food source and for the sustainable development of aquatic resources.

The growing worldwide population has led to an increase in food query and aquaculture is one of the production sectors to supply feed required by the world. It is thought the aquaculture should be maintainable. However, the expansion of a sustainable aquaculture commerce has been hindered by the restricted accessibility of natural resources as well as its undesirable impact on the surrounding environment. The prime goal of aquaculture expansion must be to produce more product deprived of significantly increasing the usage of the basic natural resources of water and the land. The second goal is to develop sustainable aquaculture system that will not destruct the environment. The third goal is to built up systems providing an equitable cost/benefit ratio to support economic and social sustainability. Thus, there is a crucial need to search for better aquaculture production systems. All these three fundamentals for sustainable aquaculture development can be met by biofloc technology

The current study was carries out to determine the effect of fish meal replacement with Aqupro on growth, blood indices and liver enzymes activities in fingerling rainbow trout. Number of 540 fish (18 g) were randomly distributed in 18 fiberglass tanks (250 l capacity) and five isoproteic diets were formulated. The fish meal inclusion reduced from 50 percent in diet one to 10 percent in diet five. After three months feeding trial, growth, blood indices, liver and intestine histology as well as liver enzymes activity were analyzed. Fish meal reduction and increasing Aqupro levels, had no negative effect on growth parameter. The FCR, FER and SGR had no significant differences between groups.  In case of blood indices, the number of white blood cells was significantly higher in group five. Ht, Hb and RBC were significantly higher in second group. Albumin had no differences between treatments. AST and ALT is the fifth group were higher than others while ALP was higher in the control group. No damage and disfunction was seen in the liver and different part of intestine in response to addition of Aqupro.

In this study, the effects of selenium nanoparticles on the reproductive performance of rainbow trout breeders (Oncorhynchus mykiss) were investigated. A total of 84 male reproductive strains were selected from among the breeders of the Genetic and Genetic Research Center of Shahid Motahari Yasouj. After adaptation, the fish were divided into 4 experimental groups with 3 replications. Male broilers fed with commercial foods (without selenium nanoparticles) (control group) and male brooders fed diets containing 0.5, 1 and 2 milligrams of selenium nanoparticles per kilogram of diet. After evaluating the quantity and quality of sperm, replication and fertilization were performed for different groups using female oocytes. The results showed that the highest volume of sperm and the highest sperm density were observed in rainbow trout fed with 2 mg selenium nanoparticles per kilogram of diet. The lowest sperm volume was observed in the control and 0.5 mg selenium nanoparticles and the lowest sperm density was observed in the control group. The duration of sperm motility in fish fed diets containing selenium nanoparticles (0.5, 1 and 2 mg) was significantly higher than that of the control group fed with selenium nanoparticle diet. No significant difference was found between the percentage of sperm motility and spermatocrit between experimental groups. The highest percentage of fertilization, laceration and hatching of eggs were from rainbow trout breeders fed with 2 mg nano-selenium per kilogram of diet. In this study, the supplementation of the male breeder diet with selenium nanoparticles did not have a significant effect on progeny survival at the onset of active feeding. Selenium nanoparticles seem to have a positive effect on hatching eggs ob n embryos and larvae, but in the onset of active nutrition, there is no significant effect on the survival of larvae. selenium nanoparticles of diet improve the reproductive performance in male rainbow trout.

Recently use of Acidifier (group of organic acids) increased in aquaculture. The purpose of this study was to evaluate the effects of acidifier (sodium diformate and citric acide) on growth performance, nutrition indices, immune and hematological parameters of the juvenile Oncorhynchus mykiss. A total of 630 juvenile Oncorhynchus mykiss (16.55 ± 0.72) randomly divided into seven experimental treatments (Three replicates each). All groups fed with experimental diet for 60 days. Bioassay conducted in first day and after sixty days and then growth parameters were investigated. The experimental diets were contain 0.2, 0.4 and 0.6 % sodium diformate(NDF) and 0.2, 0.4 and 0.6 %, combination of NDF and citric acid with equal ratio. Diet control was without acidifier. Results showed that almost all growth and hematological parameters were increased in fed groups with 0.2 % supplemented food with NDF and citric acid compare to the control group. The best FCR showed in the groups fed with 0.2 % (P<0.05). Although haematological parameters of fish in groups fed by 0.2, 0.4 and 0.6 %, NDF and citric acid changed significantly after 60 days of feeding with experimental, no changed were observed in WBC value among the groups (P>0.05). The results show that the immunological parameters including, total serum protein, immunoglobulin and bactericidal activity serum were affected significantly at Acidifier (p<0.05) while Lysozyme activity serum and albumin was not affected (P>0.05).  The results of this study indicated that 0.2 %, NDF and citric acid in the diet could be a useful food supplement and can be used to improve the growth parameters and immunity system in juvenile Oncorhynchus mykiss.

Iranian cichlid fish is one of the unique ornamental fish such as other fishes, feeding cost is determined the final product price. On the other hand, invasion of Azolla to Anzali lagoon changed it to a pond. By using Azolla powder in Iranian cichlid fish feed formulation, it can be an opportunity to optimum utilization of this aquatic plant. In this study, different percentages of this plant powders (15, 30, 45 and 60%) was replaced to basic feed protein resources, fed for 8 weeks, 4 times per day on sanitation to fish with weighing 4.0±0.3 g. Food was purchased from CP Company, Thailand with 40% crude protein, including fish, soya, corn, squid and head of shrimp) with 41% iso-nitrogenous and 4230 kcal per 100 g of dry weight, iso-caloric. Results showed that azolla as a protein supplement replaced with protein sources of Iranian cichlid fish feed formulation without any adverse impacts on growth performance (P>0.05), with statistical impact on survival (P<0.05). Treatment with 45% replacement led to increase in body weight but higher replacement percentage caused negative effect on growth performance and survival rate.

In this study, the effect of feeding with different sources of zinc supplements on reproductive indices of male rainbow trout was investigated. Feeding treatments for 16 weeks of research period included: (1) male broodstock fed with diet containing 40mg/kg of inorganic zinc, (2) male broodstock fed with diet containing 40mg/kg of zinc nanoparticles, (3) male broodstock fed with diet containing 40mg/kg of organic zinc and (4) male broodstock fed with zinc-free diet (control). Breeding and fertilization were performed for different treatments using the control of female oocytes. The highest percentage of fertilization eyed eggs and hatched eggs were observed in rainbow trout broodstock fed with diet containing 40mg/kg of inorganic zinc. Sperm concentration, volume, and motility duration, as well as hematocrit percentage, were higher in all treatments supplemented with zinc compared to control. Offspring survival up to 1g of weight was significantly higher in fish fed with diet containing inorganic zinc than other treatments (P<0.05). The results of this study showed that zinc supplements would play an important role in improving the capability and functional performance of male rainbow trout.

This research investigated the influence of selenium nanoparticles (SeNPs) on the reproductive performance of female rainbow trout (mykiss Oncorhynchus) broodstocks. A total of 120 female broodstock were selected from breeders of the Shahid Motahary Coldwater Fishes Genetic and Breeding Research Center. After adaptation, fish were divided into four treatments in three replicates. Fish were fed diets containing 0 (control) 0.5, 1 and 2 mg SeNPs per kg of diet for 60 days. Eggs quality parameters such as fecundity, fertilization rate, eyed egg rate, hatching, etc. were evaluated. The highest fertilization rate was observed in fish fed with 2 mg selenium (99.30%), which had a significant difference with control groups (p< 0.05) but did not show any significant difference (p>0.05) with fish fed 0.5 mg and 1 mg SeNPs. Broodstocks fed with 2 mg SeNPs had the highest absolute fecundity, which had a significant difference with groups fed 1 mg SeNPs (p <0.05), but did not show significant difference with other two treatments (p >0.05). ) The highest and the lowest relative fecundity were seen in group fed 2 mg SeNPs and 1 mg SeNPs, respectively. However, there was no significant difference in relative fecundity between treatments (p >0.05). The highest egg diameter was in fish fed 0.5 mg SeNPs. Egg diameter in the control group, fish fed 2 and 1 mg SeNPs, were 5.39, 5.39 and 5.40 mm, respectively). There was no significant difference for egg diameters among gruops (p> 0.05). The highest and the lowest mean total egg weight were in group fed 0.5 mg SeNPs and 1 mg SeNPs, respectively, and no significant differences were observed between treatments (P >0.05). The highest percentage of hatching was observed in groups fed 2 mg SeNPs, which had a significant difference with other treatments (p <0.05). The highest survival rate was observed in groups fed 2 mg SeNPs too, which showed no significant difference with other treatments (p >0.05). Increase in the survival rate associated with an increase in the concentration of SeNPs. In general, inclusion of SeNPs in diet, improve the quality and quantity of eggs and reproductive function (fertilization, eyed rate and hatching) in rainbow trout breeders.

In the present study, the effects of feeding with different sources of zinc supplements including mineral, nanoparticulate, and organic forms on the enzymatic and ionic changes of seminal plasma in rainbow trout broodstocks were investigated. A total of 108 broodstock males with mean weight of 2138±93.45 g were fed during 16 weeks in four treatments with adding 40 mg. kg-1 of 1. Mineral zinc supplement, 2. Zinc nanoparticles supplement, 3. Organic zinc supplement, 4. Broodstocks fed with control diet with no adding of zinc supplement. According to the findings related to the effect of different rations on seminal plasma enzymes, the lowest levels of ALT, AST, LDH and SOD enzymes were recorded in fish fed with mineral zinc supplement. These values were significantly different compared to the control with the highest levels (p˂0.05). There was no significant difference in ALP value between different treatments (p>0.05). Catalase and glutathione peroxidase enzyme values were not significantly different between treatments (p>0.05). Regarding the effect of different zinc supplements on inorganic compounds of seminal plasma, it was observed that the phosphor ion was not affected by these supplements (p>0.05) but a comparison between magnesium and calcium mean values (2.63±0.37 mg/dl and 7.23±0.15 mg/dl, respectively) in different treatments indicated a significant increase of these ion values in fish fed with mineral zinc supplement compared to the control (p˂0.05). In conclusion, regarding the decreasing effect of mineral zinc on the transaminases values and its increasing effect on the inorganic compounds values of magnesium and calcium in seminal plasma, this essential micronutrient could be considered and further investigated as an appropriate dietary supplement for improving the sperm quality of rainbow trout male broodstock.

Improvement of a diet of rainbow trout (Oncorhynchus mykiss) brooders with selenium nanoparticles has a great effect on reproductive indices. Selenium is very important for male reproduction and its deficiency and low levels can lead to reproductive disorders such as poor fertility and fetal development. In this study, the effects of different levels of selenium nanoparticles on the reproductive performance of rainbow trout male brooders were investigated. 120 four-year-old male fish weighing 2.375kg were selected. After adaptation, the fish were divided into four experimental groups (control, 0.5, 1 and 2 mg selenium nanoparticles per kg diet) with three replications. There was no significant difference in the results of the total length of male brooders. The highest fertilization rate (98.17± 1.60%) was observed in fish fed 2mg nanoselenium which had a significant difference with other treatments. The highest percentage of egg hatching was observed in the broods treated with 2mg/kg nanoselenium (93.93±3.00). The survival rate of offspring showed that with increasing levels of selenium nanoparticles in males, there was an increasing trend in offspring survival. The increasing trend of fertilization and offspring percentages in male brooders fed 2mg selenium nanoparticles had a significant effect on the final results.

In this research, measurement of serum blood glucose of cultured rainbow trout (Broodstocks) had done in two different treatments. First treatment consists of fish which were fast, and second treatment had feed. Each treatment includes 10 fish (50% male, 50% female). Blood extracted from caudal vein of each fish by a syringe. Then, serum separated with centrifugation. The amount of serum glucose measured by a kit (Man® Company, Iran). The kit worked based on glucose oxidase method. The average of blood glucose in fasting treatment, was 92.2±14 mg/dl while the average of feed treatment was 189.2±17.2 mg/dl. Statistical analysis had done by SPSS software. Comparison of mean blood sugar concentration between two treatments by t-test showed significant difference between two treatments (p<0.05). The final conclusions showed that fish feeding gives change in blood glucose concentration. It is appeared that, bleed of fish for measurement of the serum glucose needs to do 8 hours after feeding for future research and accuracy tests and standardization of tests.

Feed comprises the main cost and adjust the economical profit in aquaculture operations. From an economical and environmental view, it is important to ensure that feed is well utilized, providing high growth rate and good health and finally ensure a high-quality production. Fish feed is formulated in order to meet the target species needs for nutrient and energy. All ingredient combined by leas-cost formulation software to satisfy nutritional requirement of the aquatic animal. Knowing the high cost of feed in aquaculture units, highlights this point that high quality feed production in factory and best feeding management in farms, is on both side responsibilities. The farmer is in charge for best feeding administration, suitable storage and feed handling. Any neglection in this area may results economic lost and complications. Awareness of symptoms and problems caused by poor feed quality, feed spoilage and unfavorable condition causers in feed and store and quality control program care, helps the aquacultures units to optimize their practice.

Taurine, or 2-aminoethanesulfonic acid, is an end product of metabolism of sulphur-containing amino acids. Taurine is found in eggs, fish, meat, and milk, but not in vegetable proteins. It is present in high concentrations in heart, retina, skeletal muscle, brain, large intestines, plasma, blood cells and leucocytes. Therefore, this amino acid plays significant roles in many physiological functions, including membrane stabilization, antioxidation, detoxification, modulation of immune response, calcium transport, myocardial contractility, retina development, bile acid metabolism, osmotic regulation and endocrine functions. In the past, taurine has not been considered as an essential nutrient for fish. However, recent studies have indicated that taurine synthesis widely differs between fish species and demonstrated that it plays a key role in nutrition of fish and shellfish. Fish meals, which are the primary protein source in aquaculture feed industry, have become costly and of limited availability. In recent years, plant-based protein sources, have been receiving considerable attention as a partial or total fishmeal replacer in aquaculture feed industry. However, most ingredients of plant origin are limited in a number of nutrients, including taurine, which might be necessary for the optimal performance and metabolism of farmed aquatic animals, particularly for carnivorous fish. Plant protein sources are deficient in taurine or its precursors, namely cysteine and methionine. The inclusion of high levels of plant protein in fish feeds is cause deterioration in fish performance, possibly due to the inability, or low ability, of these fish to synthesize taurine. On the other hand some freshwater teleost fish are able to synthesize taurine from methionine and cysteine. In this review we describes the taurine sources, requirement levels in some farmed species, and highlights the biological activities of taurine.

IHNV (Infectious Hematopoietic Necrosis Virus) is one of the most important pathogens in cultured rainbow trout (Oncorhynchus mykiss). The virus causes the disease that affects the hematopoietic tissue and blood vessels of fish, especially in larvae and fingerling stages. The disease is highly contagious and causes mass fish casualty (up to 95%). Therefore, continuous health monitoring of fish farms is necessary. The objectives of the present study were to identify and track the probable presence of the virus in fish farm in Dasht-e-Rome, Kohgiluyeh and Boyer-Ahmad province, Iran. Samples were prepared from the liver, spleen, kidney, egg, sperm and larvae of the adult fish and broodfish during four years from 2012 to 2016. About one percent of the broodstock population was used for sampling (1%×3000 broodfish×4years=120fish). In order to detect the presence of IHN-virus, samples were sent to a laboratory in frozen condition. After preparation of samples, they were inoculated with two types of cell line (BF2 and EPC) and examined by the molecular methods (Reverse Transcriptase-PCR) to detect the presence of IHN virus. The results showed that all samples were free from the IHN virus and the frequency of virus was 0% in all examined samples.

The golden trout have undergone genetic alterations in the must fish farm for lack of separate breeding and Non-normative fertilization between them and rainbow trout (oncorhynchus mykiss). Thus, the preparation of pure strain is very useful and effective in research centers and commercial scale ,according to the marketability of golden trout and their importance in all-female and all-male fish production . Then we can expect to distribute in fish farm across the province and the country and it s reliable Results of the project applications . Therefore in this study , golen trout and rainbow trout broodstocks were fertilized and were evaluated the eyed percentage, hatch rate, fry and survival percentage to weight of 10g.

The effect of salinity stress on theþ þhaematological and serum biochemical parameters of Persian ýsturgeon (Acipenser persicus) juveniles fed with different levels of Nucleotide-supplemented diet ýwas examined in this study. Fish (42.37± 2.12 g and 23.67± 0.61 cm) randomly were divided to ýfour treatments with different levels of dietary nucleotides (0, 0.25, 0.35 and 0.5 % diet). After 10 ýweeks feeding, salinity abruptly increased to 12 ppt. Serum biochemical and blood parameters were ýmeasured at 0, 12, 24, 48, 72 and 120 hours after salinity stress. One-way ANOVA using the ýresults significantly in the Spss 18 software was used for analysis. Duncan test was used for mean comparingý. After 12 hours after salinity ýstress, control group significantly showed the lowest values of total protein, albumin and ýeosinophil, and highest value of magnesium while the highest value of albumin found in group fed ýý0.50 % NT. 24 hours after salinity stress, treatments fed 0.35 and 0.50 % NT, significantly showed ýthe highest values of Hct and RBC. Also the lowest eosinophil was seen in treatment 0.50% (P ≤ ýý0.05). 48 hours after salinity challenge onset, glucose and MCHC in control group significantly ýshowed the highest values compared to NT-treated groups while there was a significant decrease in ýcalcium as NT level increased. The Mg value, 72 hours later, was significantly higher in treatment ýý0.50%. Finally, in the last blood sampling (T120), the lowest value of heterophil was found in ýtreatments 0.35 and 0.50 (P ≤ 0.05).ý

This study was aimed to examine the impact of different levels of dietary nucleotides (Vannagen) on serum biochemical and blood parameters of Persian sturgeon (Acipenser persicus). Fish (42.37± 2.12 g and 23.67± 0.61 cm) were divided into four treatments with different levels of dietary nucleotides (, 0.25, 0.35 and 0.5 percent of diet). There were three replicates with a density of 12 fish per tank. After 1 weeks of feeding, serum biochemical and blood parameters were measured. Among the measured factors, blood glucose, triglycerides, cholesterol, erythrocyte and heterophil showed significant differences between the groups fed with nucleotides and the control group (P ≤ 0.05). By increasing the nucleotide levels, the mean heterophil and serum glucose showed significant increase and decrease, respectively. The highest and lowest values of cholesterol and triglyceride were found in groups fed with 0.25% and 0.35% nucleotides, respectively. The other measured factors had no significant difference (P≤0.05). Therefore, it could be said that with regard to the limited capacity of cells to synthesize nucleotides, external preparing of nucleotides could result in the production of needed nucleotides and an increase of its production speed, especially during stress. Such preparation can also improve fish physiology and health status.