محمود محسنی

The initial feeding of larvae is a critical stage in fish development that significantly influences the enhancement of quality, reduction of skeletal abnormalities, resilience to stressful environments, and future survival rates of fish. The transition stage facilitates external feed adaptation in larvae, providing both live and formulated feeds. This period involves gradually reducing the consumption of live feed while increasing the amount of formulated feed. In this study, we aim to investigate the effects of various live feeds (such as Artemia and chironomid larvae) and dry feeds on the Siberian sturgeon, Acipenser baerii growth performance, survival rate, and digestive enzyme activity.

A 34-day study was conducted to investigate the effects of mixed-formulated diets and various live feeds on growth, survival rate, and digestive enzyme activity in the larvae of Siberian sturgeon. The larvae were fed Artemia nauplii during the 8 to 20 days following larval hatching. A total of 1,500 larvae, each with an initial weight of 0.24 ± 0.00 g, were randomly distributed into 15 plastic containers, each with a capacity of 50 liters, across three replicates (n = 100). Larvae were fed using five different feeding strategies: frozen chironomid larvae (CH), frozen Artemia biomass (Ar), a combination of Artemia biomass and chironomid (M), a mixture of Artemia, chironomid and dry feed (MF), and dry feed alone (FD). All treatments replaced 10% of the consumed live feed with dry feed every three days. The larvae were fed ad libitum.

The final weight and biomass of larvae in CH were significantly higher than in M and MF. The fish in CH and then FD had the highest final weight, yield, and production value. Furthermore, CH and FD exhibited the most apparent increase in the amounts of digestive enzymes, including pepsin, trypsin, and amylase (P<0.05).

According to the results, Siberian sturgeon larvae experienced rapid physiological and morphological changes during the early stages of their life cycle. Dry feed with high digestibility can be used to initiate external feeding. Additionally, frozen chironomid larvae are recommended as a feed supplement during this crucial weaning stage due to their high digestibility, improved survival rate, and reduced production costs.

Polychaeta, or bristle worms, are a class of marine Annelid worms with segmented bodies. Each segment has paired fleshy appendages called parapodia, equipped with bristles known as chaetae made of chitin. Over 10,000 species are described, and polychaetes play vital ecological roles as predators and prey in their ecosystems. Polychaeta, Hediste diversicolor is one of the important live foods in fish and crustacean nutrition such as sturgeon and shrimp. This study aimed to investigate the effect of different levels of selenium nanoparticles (Se-NPs) and iron nanoparticles (Fe-NPs) on the growth and survival of H. diversicolor.

48000 Hediste worms (with an average wet weight of 37 mg) were distributed in 12 tanks (50-L volume) as a completely randomized design with four treatments and three replications (4000 worms per m2). Treatments included control (without adding nanoparticles), T1 = 50 mg/kg Fe-NPs + 0.5 mg/kg Se-NPs, T2 = 100 mg/kg Fe-NPs + 1 mg/kg Se-NPs and T3 = Fe-NPs 200 mg/kg + 2 mg/kg Se-NPs. Before starting the experiment, Hediste worms were adapted to the tank conditions for one week, and then they were fed diets containing selenium and iron nanoparticles for 12 weeks.

The results indicated that increasing the amounts of selenium nanoparticles (Se-NPs) and iron nanoparticles (Fe-NPs) in the diet significantly enhanced the biomass and survival rate of Hediste worms. Specifically, as the concentrations of selenium and iron in the treatments increased, the length of L3 (the combined length of the first three segments: prostomium, peristomium, and first chaetiger) decreased significantly. T2 and T3 exhibited shorter L3 lengths compared to the control group. The highest survival rates were observed in T2 (65.5%) and T3 (66.6%), while the greatest biomass was recorded in T3 (1514.8 g/m²). Notably, Hediste worms in the control group consumed significantly more food and displayed the highest food conversion ratio (FCR). In contrast, the lowest FCR values of 0.57 and 0.54 were recorded in T2 and T3, respectively, indicating a positive effect of these nanoparticles on improving FCR.

The combined application of Se-NPs at a concentration of 2 mg/kg with 200 mg/kg Fe-NPs demonstrated a superior effect on the growth and survival rate of Hediste diversicolor compared to both the control diet and other treatments.Conflicts of interest: Authors have no conflict of interest to declare for the publication of the present work.Acknowledgments: This research was conducted as a study opportunity for members of the faculty of the Agricultural Research, Education, and Extension Organization in Society and Industry. We would like to thank the Zist Palayeshgar Khazar Company (ZPK) and the International Sturgeon Research Institute.

Aquaculture is increasingly vital for meeting the protein needs of a growing global population. Successful production relies on efficient feed, which accounts for 60% of costs, and the development of high-quality products. Disease management in aquaculture is challenging due to factors like poor nutrition and environmental conditions, making prevention more critical than treatment (Ndashe et al., 2023). Current strategies focus on using immune stimulants and additives, such as organic acids, probiotics, and prebiotics, to enhance fish health and resilience against diseases (Dawood et al., 2018). The use of natural growth stimulants like chitin, chitosan, and lactoferrin has surged due to their economic benefits and minimal environmental impact. These substances not only improve immune responses but also enhance the antibacterial activity of phagocytic cells, contributing to sustainable aquaculture practices. Overall, the shift towards these natural alternatives reflects a growing recognition of their value in promoting fish health and reducing reliance on chemical treatments. Chitosan is a biodegradable and biocompatible polysaccharide derived from glucosamine through the deacetylation of chitin, predominantly found in the exoskeletons of crustaceans, particularly shrimp shells. It offers numerous benefits in aquaculture, notably enhancing fish health and growth. Chitosan stimulates the immune system by increasing levels of immunoglobulin M (IgM) and lysozyme activity, which improves disease resistance. It also boosts antioxidant capacity by enhancing the activity of enzymes like superoxide dismutase (SOD) and catalase (CAT), thereby reducing oxidative stress. Additionally, chitosan promotes gut health by increasing intestinal villi length and digestive enzyme activity, facilitating better nutrient absorption (Mukarram et al., 2023; Zhang et al., 2024). Moreover, chitosan can chelate heavy metals such as cadmium, mitigating their toxic effects on fish, and its antibacterial properties help maintain gut microbiota balance by preventing pathogenic bacteria while promoting beneficial ones. Overall, dietary chitosan supplementation has been shown to enhance growth, health, and stress resistance in various fish species, making it a valuable additive in aquaculture. In the context of sturgeon (Huso huso) farming in Iran, reducing juvenile fish mortality and increasing growth rates are critical for economic efficiency, highlighting the importance of suitable diets and micronutrient balance to enhance immune function and production efficiency.

The extraction of chitosan from shrimp shells was carried out through four stages: demineralization, deproteinization, decolorization, and deacetylation. 1260 fish (2.87 ± 0.07 g) after passing the acclimatization period, were fed in 18 tanks with six experimental diets, including control diet (without chitosan, T1), 0.15% (T2), 0.3% (T3), 0.45% (T4), 0.6% (T5) and 0.75% (T6) of chitosan (n=3) for 12 weeks. Then all growth indices such as final weight, growth rate, Protein Efficiency Ratio, and FCR, immunological parameters like lysozyme, ACH50, total immunoglobulin, and IgM were measured. The body composition also was measured after 12 weeks.

The final body weight and body weight gain in treatments containing 0.45%, 0.6%, and 0.75% chitosan were significantly higher compared to the control, 0.15% and 0.3% chitosan treatments. The specific growth rate significantly increased with the higher levels of chitosan, and no significant difference was observed in the group fed with 0.15% chitosan compared to the control group. The hepatosomatic index significantly improved in all chitosan-fed treatments compared to the control group (P≤0.05). The feed conversion ratio significantly improved with increasing levels of chitosan compared to the control group. The protein efficiency ratio also increased in the treatments fed with 0.45%, 0.6%, and 0.75% chitosan compared to the control group, but no significant differences were found in the treatments fed with concentrations of 0.15% and 0.3% chitosan (P≥0.05). The lowest carcass protein level was observed in the control treatment, which showed a statistically significant difference compared to the carcass protein levels of other treatments, except for the 0.15% chitosan treatment (P ≤ 0.05). The carcass protein levels in the 0.45%, 0.6%, and 0.75% chitosan treatments were the highest, but no significant differences were observed among them. The carcass fat level in the 0.45%, 0.6%, and 0.75% chitosan treatments was significantly lower compared to the control group (P≤0.05). With the increase in chitosan concentration in the diets, the serum lysozyme levels significantly increased except for the group consuming 0.15% chitosan (P≤0.05). The results obtained from the complement activity (ACH50) measurements showed that with the increase in chitosan levels in the diet, this indicator significantly increased in the serum (P≤0.05). The total serum immunoglobulin and IgM levels, also increased significantly compared to the control group (P≤0.05).

Chitosan, has gained attention in aquaculture for its potential as a growth promoter and immunostimulant. Research indicates that dietary chitosan enhances growth performance, feed efficiency, and immune responses in various fish species, including Nile tilapia, common carp, and golden pompano. Optimal chitosan levels, typically ranging from 0.5% to 2%, have been shown to improve weight gain, feed conversion ratios, and overall health status by promoting gut health and enhancing digestive enzyme activities. Studies also highlight chitosan's role in modulating serum biochemical parameters, reducing fat accumulation in the liver, and improving intestinal morphology. The balance of chitosan dosage is crucial, as it can enhance beneficial bacteria while inhibiting harmful ones, thereby supporting the fish's immune system. Overall, chitosan represents a promising, eco-friendly alternative to antibiotics in aquaculture, contributing to sustainable fish farming practices while improving the health and productivity of cultured species. Chitosan also enhances nonspecific immunity and reduces mortality in fish, as evidenced by studies on common carp (Maqsood et al., 2010). However, its effects on feed consumption and conversion ratios can vary, with some studies showing no significant impact on these parameters despite improvements in liver health (Stanek et al., 2023). Overall, chitosan's role in aquaculture highlights its potential as a dietary supplement to improve fish health, growth, and resistance to environmental stressors. Serum parameter measurements are crucial for assessing the metabolic and physiological health of fish, particularly in aquaculture where they are susceptible to opportunistic bacterial infections. Lysozyme activity, an indicator of immune health, was found to increase with dietary chitosan levels. Research indicates that chitosan enhances lysozyme activity across various fish species, including loach, cobia, silver carp, vannamei shrimp, and rainbow trout. Additionally, chitosan supplementation in diets for beluga sturgeon and hybrid sturgeon also boosted lysozyme levels. Chitosan's immune-boosting effects are attributed to its ability to scavenge free radicals, enhancing innate immunity. Complement activity, vital for non-specific immune responses, also increased in fish like Nile tilapia and mrigal when fed chitosan. However, responses to chitosan vary by species and concentration, with some studies indicating potential negative effects at higher doses. Furthermore, IgM levels, a key immunoglobulin in fish, significantly increased with chitosan supplementation, reinforcing its role in adaptive immunity. Overall, optimal chitosan levels in fish diets can significantly enhance immune responses and health. The increase in IgM levels with dietary chitosan is not fully understood, necessitating further research to clarify the mechanisms involved (Salam et al., 2024). Studies indicate that chitosan enhances IgM and total protein levels in fish, such as rainbow trout and golden pompano, although excessive chitosan (10 g/kg) can reduce these benefits (Yu et al., 2023). In tilapia, IgM levels increased significantly up to 1.5% chitosan but decreased at 2% (Zhang et al., 2024). Additionally, recombinant chitosan nanoparticles show promise as alternatives to antibiotics in aquaculture, potentially enhancing disease resistance. This research supports using chitosan in beluga fry diets to improve growth and immune performance while reducing antibiotic reliance, particularly at levels of 0.45% to 0.6%, which positively affected growth, body composition, and immune parameters.

Fishmeal price were increasing every year and predicted that fish diet will have a wider range of ingredients replaced by fishmeal, such as vegetable sources, microbial protein sources, waste from fishing and animal protein waste (Glencross et al., 2007). Vegetable proteins can replace fish meal to some extent and have a negative effect on the growth of aquatic animals at high levels. But many studies have shown that a mixture of vegetable proteins can improve the amino acid profile compared to single protein source replaced by fish meal (Amaya et al., 2007).  By this method, high replacement with a blend of protein Vegetables have been reported in aquatic animal (Hansen et al., 2007), but increasing fiber, increasing carbohydrates and inappropriate amino acids in diets based on animal and vegetable proteins can led to a negative effect on fish digestive system that showed by growth reduction, immune system depress , low quality meat and even fish fatality in a long-term feeding period (Raskovic et al., 2011). therefore, in this experiment, the effect of a mixture of animal and vegetable proteins replaced by fish meal (levels of 20, 40, 60 and 80%) on the growth indices and digestive system tissue Huso huso were studied.

In order to reduce the share of fishmeal in the diet of beluga, a basal diet based on 54% of fishmeal was made. A mixture of animal and vegetable proteins (corn gluten: 35%, wheat gluten: 19.34%, processed soybean flour: 3%, chicken by-products: 20%, meat and bone meal: 8%, blood meal: 3.4%) at 20, 40, 60 and 80% levels replaced with fishmeal (FM) (CGM20, CGM40, CGM60, and CGM80, respectively) and finally 5 isonitrogenous (44% crude protein) and isoenergetic (18 MJ/kg) diets were produced. The fish (Average weight: 167±6.5 gr) were fed to saturation for 12 weeks.  Biometry were carried out on month interval and by carrying out information obtained from fish length, weight and food consumption, growth indices and feed efficiency ratio were calculated. At the end of the feeding period, 30% of the fish population was collected from each tank for histological studies. Three parts of the intestine (hindgut, midgut, and foregut) were removed. It was fixed and stained. Histological studies were carried out by an optical microscope equipped with a monitor.

There was no significant difference in the final weight and length of fish of different treatments (P>0.05). condition factor and percentage of weight gain of fish fed with FM, CGM20, CGM40, CGM60 and CGM80 had no no significant difference and percentage of weight gain was close to each other (243 to 298%) (P>0.05). No significant difference was observed in specific growth rate and daily growth rate and food conversion ratio in fish fed with all diets (P>0.05). Fish fed FM had the highest protein efficiency ratio (1.75±0.23), but protein efficiency ratio in fish fed with CGM20, CGM40, CGM60 and CGM80 was in the range of 1.53 to 1.73%. But no significant difference was observed (P>0.05). Histological studies were carried out by an optical microscope equipped with a monitor. The intestinal tissue of fish fed with CGM80 diet had necrosis and biliary stagnation. However, histological studies in fish fed with FM, CGM20, CGM40, and CGM60 diets showed that the lamina propria space is adequate, the necrosis of enterocytes is negligible, and the number of goblet cells in the anterior, middle, and distal intestine is balanced. The final results confirmed that the CGM80 did not a negative effect on the growth fish, but it caused damage to the digestive system.  In the present study, there is no significant difference in growth indices and food conversion ratio of fish fed with diets based on fish meal and diets based on corn gluten flour (a mixture of corn gluten: 35%, wheat gluten: 19.34%, soybean meal processed: 3%, poultry by product: 20%, meat and bone meal: 8%, blood powder: 4.3%). In this order, it seems be that alternative diets formulation based on a mixture of Animal and vegetable protein sources  were led to enriching of profile and biochemical composition of diet, In addition beluga Compared to white and Siberian sturheon is a species that can be fed with high carbohydrates percentages without growth reduction (Mohseni et al., 2011). In the present experiment, by increasing mixtures based on corn gluten-based in fish diet,  goblet cells were increased and reached to highest value in CGM80. goblet cells are related to immune system and mucus secretion in order to fluidity of digestive tract and create a protective barrier against mechanical and chemical damage (Marchetti et al., 2006). it seems that the increase of goblet cells in beluga fed with a mixture of vegetable proteins (CGM60 and CGM80) is a reaction against to mucous layer necrosis and reduction of intestinal villi in order to further damage of folds by secreting more mucins (Li et al., 2007), but in general, digestive tract epithelium damage in fish fed CGM20, CGM40 diets and CGM60 was negligible compared to fish fed with FM diets and did not lead to enteritis (intestinal inflammation). Therefore, it is suggested to replace fishmeal with a mixture of animal and vegetable proteins at 20 and 40% in Huso huso diet during the fattening stage.

The aim of the research was to determine the effect of feeding frequency on growth indicators, carcass composition, activity of some digestive enzymes and survival of beluga (Huso huso) larvae. For this purpose, the total number of 10800 beluga larvae, with initial weight of 0.048+0.001 g, were randomly stocked in 36 500-liter fiberglass tanks containing 100 liters of well water, for 31 days with a feeding frequency of 6 and 12 times a day using Artemia nauplii, Artemia biomass, Daphnia, chironomid larvae and formulated diet were reared. The results showed that, feeding larvae with chironomid larvae or Artemia biomass, could increase the survival rate and weight of larvae, respectively. The survival percentage of the treatments on different days after hatching of the larvae during 12 times of feeding per day in most treatments was significantly higher than that of 6 times of feeding per day (p<0.05). The average weight of larvae in different treatments, when feeding 12 times a day compared to feeding 6 times a day, had no statistically significant difference (p>0.05). In most treatments, carcass protein content of larvae, during 12 and 6 times feeding a day, had no statistically significant difference (p>0.05). But the carcass fat content, during 12 times feeding per day in half of treatments, was significantly higher than 6 times feeding per day (p<0.05). The activity of pepsin, trypsin and lipase enzymes, during 12 times feeding a day was significantly more than 6 times a day feeding. Totally, feeding larvae 12 times a day was preferable to feeding 6 times a day, based on improvement of survival of larvae, condition factore and activity of enzymes.

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

This study was conducted to evaluate the effects of replacing fishmeal with fermented soybean meal on some hematological and immunological indices of Beluga, Huso huso. For this purpose, 240 Beluga (394.6 ± 4.3 g) were distributed in eight treatments (with three replications). The experimental treatments included T1: fish meal (FM), T2: (FM + methionine and lysine), T3: Fermented soybean 40% (FSBM40), T4: (FSBM60), T5: (FSBM80), T6: (FSBM40 + methionine and lysine), T7: (FSBM60 + methionine and lysine) and T8: (FSBM80 + methionine and lysine). During the 56-day feeding period, the fish were fed to apparent satiation three times daily. The results showed that there was no significant difference in hemoglobin, hematocrit, MCHC, neutrophil, monocyte and eosinophil values (p>0.05). However, the highest number of white and red blood cells was observed in the diets containing FM and FM + methionine and lysine, respectively (p<0.05). Furthermore, higher amounts of MCV and lymphocytes in T6 and higher amounts of MCH in T5, T6 and T8 were observed than in the other treatments (p<0.05). Also, the highest amounts of lysozyme were observed in T4. In addition, T4 and T7 exhibited higher amounts of IgM and total immunoglobulin than the other treatments (p<0.05). Based on the results, the best performance of hematological and immunological indices was observed in replacing 40-60% fishmeal with fermented soybean meal.

Thiamine, or vitamin B1, is an important coenzyme in lipid, carbohydrate, and protein metabolism that plays a vital role in the embryonic stages and larval development. To evaluate the effects of thiamine on incubation indices of beluga Huso huso, eggs obtained from farmed males and females after fertilization were immersion in water-soluble thiamine with four treatments and two replicates including control (0 mg thiamine per liter of water), T500 (500 mg thiamine per liter of water), T1000 (1000 mg thiamine per liter of water) and T1500 (1500 mg thiamine per liter of water) during water hardening for 30 minutes. Then, eggs were washed five times with fresh water and kept in special incubators until hatching. Incubation indices and larval growth were investigated 24 hours after fertilization to 44 days after starting feeding. Results showed the highest and lowest egg survival at 24 hours after fertilization until hatching were observed in T1500 and control, respectively (P<0.05). At the start of the feeding the results showed no significant difference in larval weight and length (P>0.05). However, thiamine increased the weight, length, and weight gain in T1000 and T1500 at the end of the experiment (P<0.05). Egg immersion in soluble Thiamine led to an increase in the specific growth rate and body weight in T1000 and T1500 at day 36 after the start of feeding (P<0.05). The food conversion ratio, protein efficiency ratio, and lipid efficiency ratio significantly decreased in control and T500 compared to other treatments (P<0.05). The lowest larval survival was observed in control at the beginning of feeding until day 44 (P<0.05). The results of this study indicate that immersion of eggs in thiamine solution can increase larval growth and survival. Therefore, it is recommended that beluga eggs immersion in thiamine solution at least 1000 mg L-1 thiamine after fertilization

The present study was designed and implemented to evaluate the effects of relative replacement of different levels of dehulled soybean meal (DHSM) instead of fish meal on growth performance of adult Persian sturgeon (Acipenser persicus). In this study, a total of eighty 4-year-old Persian sturgeons (Acipenser persicus), with an average weight of 3850 g were fed with 8 isonitrogenetic and isolipidic diets for 52 weeks. Experimental diets include different percentages of dehulled soybean meal include 0, 10, 15, 20% without amino acid, 15 and 20% replacement with lysine and methionine, and 15 and 20% replacement with lysine and methionine and L-carnitine supplement (DHSM0, DHSM10, DHSM15, DHSM20, DHSM20+AA, DHSM15+AA, DHSM20+AA+L.car. DHSM15+ AA+L.car.). After 52 weeks, no significant difference was observed between weight gain (WG), specific growth rate (SGR), LX and PV in different treatments. The protein efficiency ratio and feed efficiency (FE) in DHSM0 was significantly higher than that of DHSM20+AA and DHSM15+AA. Hepatosotic index of fish in DHSM0, DHSM10, DHSM15, DHSM20 + AA+L.car. DHSM30 + AA+L.car. was significantly higher than that in DHSM30 + AA. Gonadosomatic index exhibited alterations under the influence of the diet.  Effect of diets containing dehulled soybean meal with L-carnitine supplement on the reproductive system of female fish was significant and positive. The somatic growth in female Persian sturgeon was higher than that of males. However, their gonadic growth and stages of sexual maturity were significantly lower than that in males. The highest sexual maturity index of male fish was observed in DHSM15 + AA+L.car diet, so that at the end of the rearing period, 75% of fish were in stage IV of sexual maturity and 25% in stage III-IV. Addition of L-carnitine and essential amino acid supplement such as lysine and methionine to the diet containing soybean meal displayed a positive effect on the growth and reproductive indicators in the functional diet of Persian sturgeon and probably can improve significantly the production of Persian sturgeon fry.

This study investigated the effects of different levels of vitamin E on growth performance and blood indices of Caspian trout (Salmo caspius) juveniles. Six diets with different levels of vitamin E including 0, 10, 20, 40, 80 and 160 mg kg-1 were prepared. The actual amounts of vitamin E in diets were determined using high performance liquid chromatography and were as follow: 4.9, 8.6, 17.4, 35.4, 78.8 and 137.0 mg kg-1. In total, 360 fish (initial mean weight of 9.32±0.34 g) were randomly distributed in 18 cylindrical tanks (20 fish per tank) with the working volume of 900 L. Each tank was randomly assigned to each of the experimental diets with 3 replications. The fish in each tank were fed with the respective diets for eight weeks and finally their growth indices and blood parameters were evaluated. The results showed that the final weight, daily growth coefficient and feed efficiency ratio of fish increased linearly (p<0.05) and quadratic (p<0.05) with increasing the vitamin E levels and reached the highest value in fish fed with 78.8 mg kg-1 vitamin E. Significant linear (p<0.05) and quadratic (p<0.05) increases in red blood cells (RBCs) and white blood cells (WBCs), hemoglobin content and hematocrit percentage were also determined by increasing in dietary vitamin E concentration. The percentage of neutrophils in fish blood reached the lowest level after feeding with the highest amount of vitamin E (137.0 mg kg-1 vitamin E) while the highest percentage of lymphocytes was recorded in fish fed with 78.8 mg kg-1 vitamin E. The findings of the present study showed that vitamin E could improve the performance and blood parameters of Caspian trout. The best level of vitamin E was estimated to be 82.16 mg kg-1 based on the daily growth coefficient and 102.98 mg kg-1 according to WBC number.

The effect replacement of various kilka fish oil with canola oil was investigated on growth indices, body composition, and digestive enzymes of Siberian sturgeon (Acipenser baerii). One hundred and eighty fry fish (22.5±2 2.09 g average weight) were fed with four isonitroginus and isolipid diets (44 and 14%) (1: 100% fish oil (FO100), 2: 100 % of canola oil (CO100), 3: 50% fish oil+50% canola oil (CO50+FO50) and 4: 70% fish oil+30% canola oil (FO100+CO30)) for 10 weeks. The mean growth and feed efficiency indices in the fish fed with FO100 and CO100 diets were significantly lower than CO50+FO50 and FO100+CO30 (P<0.05). The changes in the canola oil/fish oil ratio caused changes in the body moisture and ash contents (P<0.05), but had no significant effect on the body protein (P>0.05). The lipase and chymotrypsin levels in the fish fed with CO50+FO50 diet were significantly higher than the fish fed with FO100 and CO100 diet. The results of this study indicated that using a combination of vegetable oil and fish oil in equal proportions has a relatively better effect on the growth indices, body composition, and digestive enzymes of Siberian sturgeon in the growth stage.

An investigation was carried out to find the effects of different Smizyme phytase levels on growth indices, body composition and nutrient digestibility of farmed Siberian sturgeon, Acipenser baerii. One hundred and eighty fish (average weight 1.19 ± 0.017 kg) were distributed in nine concrete tanks (20 fish in each tank; area = 4 m2; depth = 80 cm) and divided to 3 treatments (F0, F1000 and F2000). Fish were fed for 62 days. Results showed that physaem addition in 2000 IU (F2000) to sturgeon commercial diet (38% protein and 12.5% crude fat) leads to significant increase in final weight, daily growth rate, specific growth rate and the decreased feed conversion ratio compared to the other two groups (p<0.05). Significant raises in protein and dry matter digestibility were observed in the enzyme-fed fish compared to control diet (p<0.05). However, no significant difference in fat digestibility was observed between experimental treatments (p>0.05). Body protein was declined in F1000 and F2000, while body lipid was elevated in F2000 (p<0.05). The highest body carbohydrates was observed in F1000 (p<0.05), while no significant difference was observed in the fish body moisture fed with different diets (p>0.05). Based on the results obtained from growth indices and digestibility coefficient, we suggest adding 2000 IU/kg Smizyme phytase in the fish diet.

This study aims to compare effects of sources levels of zinc on growth and carcass quality, some haematological and serological indices of juvenile beluga sturgeon, Huso huso (Linnaeus, 1758). A number of 315 juvenile beluga sturgeon (8.4±0.29) were fed in 21 500 lit fiberglass tanks (15 fish per tank) under 7 experimental diets including 1 control diet plus 6 diets containing zinc (mg per kg of diet) in two forms of mineral (zinc sulfate) (ZnSul15, ZnSul30, and ZnSul60 treatments) and organic (chelated with methionine) (ZnMet15, ZnMet30, and ZnMet60 treatments) with three replications per treatment for 12 weeks. The best values of final weight and feed conversion ratio were observed in the ZnMet15 and ZnMet60 treatments. Red blood cells, hemoglobin, and hematocrit showed an incremental trend influenced by increased zinc supplement. Increased carcass protein in the ZnMet30 treatment was significant compared to the control, ZnSul15, and, ZnSul30 treatments (P≤0.05). Reduced carcass lipid in the ZnSul30 and ZnSul60 treatments was significant compared to the other treatments (P≤0.05). Serum triglyceride and cholesterol decreased in the ZnMet treatments compared to the control treatment. Reduced serum glucose in the ZnMet15 and ZnMet60 treatments and also increased serum lysozyme in the ZnMet30 and ZnMet60 treatments were significant compared to the control treatment (P≤0.05). Results demonstrated that most of the indices had better performance in the ZnMet treatments comparted to the other treatments and are proposed as an optimal diet for juvenile beluga sturgeon.

Fish growth is regulated by many environmental and physiological factors and is shaped by the genetic background of each organism. Insulin-like growth factor I (IGF-I) plays an important role in various biological processes of fish. This study aimed to examine the rate of expression of IGF-I mRNA growth gene at different stages of growth in local and imported rainbow trout in Iran.

Hence, local and imported trout fish in three sizes of small, medium and large, with a total mean weight and size of 453.66±244.34 gr and 32.25±6.78 cm, respectively, were obtained from the fish breeding center in Guilan province (Rasht). First, 20 mg samples of the liver tissue of the fish were obtained under sterile conditions after anesthesia from both local and imported breeds. RNA extraction and cDNA synthesis were performed according to the RT-PCR standard method in the Genetics Research Laboratory of Tonekabon Azad University.

The results showed that the expression of IGF-I gene was significantly different between local and imported breeds so that the highest and lowest gene levels were in the small size of imported breed and medium size of local breed, respectively (P<0.05). However, there was no significant relationship between the amount of gene expression and weight and length of fish (P˃0.05), while IGF-I expression showed a decreasing trend with an increase in the fish size.

These findings suggest that the IGF-I gene may play a key role in the growth and development of rainbow trout.

A feeding trial was conducted to examine the effects of dietary supplementation of betaine on growth, nutrient utilization, carcass compositions and haematological- biochemical parameters in Salmo caspius fed a plant-protein based diet. 180 fish with average weight of 9.7±0.59 g were fed the plant-protein basal diet, the basal diet with 1.4 & 2.8% betaine supplementation, or a fishmeal-based diet (control) for 11 wk. Weight gain, specific growth rate and protein efficiency ratio were significantly higher in fish fed the betaine-supplemented diet (1.4 & 2.8%) as well as control diet than in fish fed the basal diet. The lowest and highest whole body protein and lipid concentrations were significantly found in the fish fed by basal diet. Based on the results of this study, the levels of liver enzymes were significantly higher in fish fed the betaine-supplemented diet (1.4 & 2.8%) as well as control diet than in fish fed the basal diet. The value of apparent digestibility of crude protein in diet-fed fish a fishmeal-based (control) were significantly higher than fish fed plant-protein basal diet and the basal diet with 1.4% betaine supplementation (p<0.05). Based on the results of this study, could be said that increased levels of 2.8% of betaine is an effective feeding stimulant that can be enhanced the palatability and intake of plant-protein based diets for Salmo caspius, improved growth performance, feed utilization and apparent digestibility coefficient.

The current study carried out to investigate the effects of adding salt (NaCl) in the diet of beluga, Huso huso and its impacts both on the function of intestinal enzymes and growth indices and food efficiency. In this regard, 480 species of Huso huso with a mean weight of 173.8 ± 0.49 g stocked in 12 fiberglasses 2000-liter tanks for 12 weeks. They fed a diet containing different levels of NaCl including 0, 3, 6 and 9 percent. Growth indices including final weight, SGR and daily growth showed significant differences in fishes of all treatments, except the fishes fed the diet containing comparing control group (p < 0.05) Weight gain percentage of fed fish at 6% sodium chloride level was significantly higher than fish fed control but no statistically significant difference was observed between other treatments. The mean FCR in fishes of control group was significantly higher than other treatments (p < 0.05). The mean rates ofrate of intestinal enzymes including Alkaline phosphatase, protease, lipase and amylase in the fishes fed by different levels of NaCl were significantly more than control group (p < 0.05). It is suggested to achieve a higher growth rate, improve food efficiency, reduction of production costs and enhancement of intestinal enzymes function. appropriate percentage of added NaCl is to be 3-6% per kilogram of diet for farmed beluga of at 150 to 700 g.

This study was conducted to examine the effect of diets containing various amounts of soybean meal and Phyzyme® XP on hematological indicators and serum liver enzymes in Caspian trout (Salmo caspius) with the average weight of 148.1±1.98 g for 85 days. For this purpose, 240 pieces of juvenile Caspian trout were randomly distributed in six treatments, including control treatment (basic diet) and five experimental treatments including  treatment I (basic diet + 2000 IU/kg diet of Phyzyme® XP), treatment II (basic diet containing 20% soybean meal), treatment III (basic diet containing 20% soybean meal + 2000 IU/kg diet of Phyzyme® XP), treatment IV (basic diet containing 40% soybean meal), and treatment V (basic diet containing 40% soybean meal + 2000 IU/kg diet of Phyzyme® XP) with two repetitions per treatment (20 pieces of fish per repetition). The largest amounts of red blood cells and hematocrit were observed in treatments I and III, respectively, which was significantly different only from treatment IV (p<0.05). The largest amount of hemoglobin was observed in the control treatment, which was significantly different from other treatments, except treatment I (p<0.05). The highest number of white blood cells was observed in treatment III, which was significantly different from other treatments (p<0.05). The lowest serum levels of the liver enzymes, including lactate dehydrogenase and alkaline phosphatase, were recorded in treatment I and control treatment, respectively, which showed no significant difference from treatments II and III (p>0.05). Besides, serum levels of these enzymes in treatment V showed no significant difference from treatments II and III (p>0.05). Therefore, according to the results of the present study and no significant differences in the values of most of the parameters between the control treatment and treatment V, it is recommended to replace 40% soybean meal containing 2000 IU/kg diet of Phyzyme® XP, instead of fish meal, in order to achieve an affordable diet without any negative impact on health parameters in the Caspian trout.

A mixture of vegetable and animal proteins (corn gluten, wheat gluten, processed soy flour, poultry by product, meat and bone meal and blood meal) that are chemically similar (protein, fat, carbohydrate and dry matter) and similar to amino acid profiles compred fish meal were replaced fish meal in diets with identical levels of protein (44%), energy (18 MJ /kg) at levels of  20, 40, 60 and 80% (MPP20, MPP40, MPP60 and MPP80). Juvenile Huso huso with average weight of 167± 6.5 g were fed diets to saturation and their growth indices, carcass composition, hepatosomic and visceral indexes were studied. The final weight, final length, condition factor, weight gain, body weight precent, specific growth rate, daily growth, feed conversion ratio and protein efficiency ratio were not affectrd with diets (p>0.05). Carcass protein of fish fed MPP60 and MPP80 were significantly decreased compared to fish fed diet based on fish meal, while fish carcass fat increased significantly in these fish (p<0.05). There was no significant difference in hepatosomatic and visceral index in fish fed diets based on fish meal (p>0.05). The results of this experiment showed that it is possible to replace 80% of a mixture of animal and vegetable proteins with fish meal without adversely affecting growth indices, hepatosomal and visceral index  of  Huso huso in growth rate period.

This study was conducted to evaluate the effect of different levels of canola oil on growth performance and survival of Caspian salmon fry (Salmo trutta caspius) during replacement with canola oil over a period of 60 days. 180 fish fries (4.25 ± 0.68 g) with a density of 15 were distributed and introduced to 300 liter fiberglass tubs. For this purpose, 4 treatments with 3 duplication, diets including 100% fish oil, 100% canola oil, 50% fish oil and 50% canola oil, 70% fish oil and 30% canola oil (with the same protein and fat levels of 43 and 14%, respectively) were applied. The results showed that the highest weight (26.46 g), final length (13.46 cm) and specific growth rate (2.97%) were belonging to the treatment containing 50% fish oil and 50% canola oil which showed a significant difference with other treatments (p≥0.05). Moreover, the lowest value of feed conversion ratio (1.41) and the highest amount of status factor (0.09 ± 1.08) were also related to treatment 3, but these differences were not statistically significant (p≥0.05). The highest protein efficiency coefficient of 2.37 was related to the treatment containing a mixture of 70% fish oil and 30% canola oil, which showed a significant difference with other treatments (p≤0.05). The survival rate among all treatments was 100% (no losses). Based on the results, it can be concluded that the replacement of part of fish oil with canola oil (50% fish oil with 50% canola oil) in the diet of Caspian salmon not only has no negative impact on growth factors and survival of Caspian salmon, but also it will improve these factors and can decrease costs by reducing the length of the culture period.

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.

In part I, we examined the formation of the Babi and Baha’i Faiths, and the role of their leaders in the way they were propagated, and the extent to which they influenced the historiography and the recording of events. We also mentioned the differences and controversies that had plagued the Babi and Baha’i Faiths at every stage of succession to the leadership. We also talked about the efforts of the Baha’is to establish and fix their own positions as the sole heirs of Mirza Ali Muhammad Shirazi and his religion. There was also a brief critique overview of the manner which faithful Baha’i historiographers practiced in the Faith and we made 8 objections to it. This article introduces Nabil Zarandi’s History and the importance of this book. Also the Shoghi Effendi’s translation of this book entitled The Dawn Breakers and its importance and authority in historiography of Baha’ism is examined. Then, the authenticity of attribution of the translation of The Dawn Breakers to Nabil Zarandi, nicknamed as Nabil Azam, is discussed.

The present study was carried out to determine the effect of different levels of glucose and corn starch as carbohydrate sources on growth performance, body composition, digestibility, digestive and liver enzymes of Siberian sturgeon (Acipenser baerii). A total number of 120 Siberian sturgeons weighing 25.64 ± 2.80g were fed four diets including glucose 15%, glucose 30%, corn starch 15% and corn starch 30% for a period of 11 weeks. Results showed that final weight, final total length, percentage of body weight increase, specific growth rate, mean daily growth, protein efficiency ratio and condition factor in fish fed corn starch 15% were high in comparison with other treatments (P>0.05). Significant difference was seen between fish fed corn starch 30% with fish fed glucose 15% in hepatosomatic index (P<0.05). The highest content of carcass protein was seen in corn starch 15% that showed significant difference with glucose 15% and 30% (P<0.05). Fish fed glucose 15% had the highest content of carcass total carbohydrate which showed significant difference with corn starch 15% and 30% (P<0.05). The contents of lipase, pepsin, trypsin and chymotrypsin enzymes and also apparent digestibility of protein and lipid in fish fed corn starch 15% were higher than the other treatments (P<0.05). The highest contents of liver enzymes were recorded in fish fed glucose 30% (P>0.05). Based on the mentioned results, corn starch at the level of 15% can increase growth and improve body composition, digestibility and digestive enzymes in Siberian sturgeon.

Historiography in Babi and Baha’i Faiths, unlike the historiographies in many other cultures and societies, has a long story, equal to the Babi – Bahai history! The Babi - Baha’i historians have made changes in their histories during the period of the formation and evolution of these faiths, according to the changes in their leadership. Therefore, paying attention to internal conflicts and disputes, as well as strategic changes in the reign of each leader, is very important and fundamental to recognize the historiography in that era. Also Babi - Baha’i historiography is not immune from plagues such as a pious view of accepting far-fetched events, relying on the words of leaders as sacred ones contrasting with real events recorded by other historians. This article, while analyzing the changes of leadership in the Babi and Baha’i Faiths, and the shift of social power among their descendants, examines the impact of this phenomenon on the Babi and Baha’i historiography, and presents some of the challenges in studying historical books written by the Baha’i believers by providing examples and documents.

The present study was conducted to examine singlular and combined effects of manan oligosacharid (MOS) and L. plantarum supplements on growth indices and hematological parameters of Caspian trout (Salmo trutta caspius Kessler, 1877). Caspian trout fingerlings (~ 10 g) were fed with a control diet (basal diet) or supplemented diets as follows: 1) the basal diet + 4g kg−1 IMOS, 2) the basal diet + -8×108 CFU/g-1  L. plantarum)  and 3) a synbiotic diets (the basal diet + 8×108 CFU/g-1  L.plantarum + 4g kg−1IMOS) for 8 weeks. At the end of this trial, the results of the MOS supplemented and synbiotic diet showed significant increase in feed conversion ratio (FCR), weight gain (WG), feed intake (FI), protein efficiency ratio (PER), specific growth ratio (SGR) and daily growth index (DGI) compared with fish fed the control diet (p<0.05). The highest FCR and FI were observed in the control group. In the case of condition factor, the singlular and combined diets showed no significant differences (p>0.05). The results of blood indices among all treatments revealed significant differences of the number of red blood cells (RBC) compared to the control group (p<0.05). The highest and lowest number of RBC was found in L. plantarum diet and control group, respectively. The number of white blood cells (WBC) showed no significant differences with control group (p>0.05). The results demonstrated that the MOS-supplemented diet and the combined diets containing MOS and L. plantarum improved the growth performance in Caspian trout fingerlings.

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.