https://japu.gau.ac.ir/ Journal of Utilization and Cultivation of Aquatics en daily 1 Sat, 21 Mar 2026 00:00:00 +0330 Sat, 21 Mar 2026 00:00:00 +0330 https://japu.gau.ac.ir/article_7092.html This study was aimed to assess the effect of carrot powder as a natural source of carotenoid on growth performance, digestive enzymes and antioxidant activity in angel fish (weight: 2.76 ± 0.28) for 8 weeks. Five experimental diets, including the control diet (D1: without carrot powder) and diets containing carrot powder (D2: 0.5%, D3:1%, D4: 1.5 % and D5: 2%) were prepared as isonitrogenous and isocaloric in triplicate. The results obtained from body weight gain, specific growth rate and protein & lipid efficiency ratio showed that they were significantly higher in fish fed with diets D4 and D5 compared to diet D1 (P<0.05). Fish fed with D4 diet significantly showed lower food conversion ratio compared to fish fed with D1 diet (P<0.05). The condition factor and the survival rate showed no significant difference among the experimental diets. The results obtained from digestive enzymes analysis of fish intestine showed that trypsin and amylase were significantly higher in D4 and D5 than those from D1 and D2 (P<0.05); while no significant difference was observed among fish fed with D3, D4 and D5 diet. The results of antioxidant enzymes assessment from fish tissue indicated that SOD and catalase in fish fed with diets containing carrot powder had a significant decrease compared to control group in both before and after stress (P<0.05). Based on the results obtained from this study, the growth performance, digestive enzymes and antioxidant activity in fish fed with diets containing carrot powder especially in high level (1.5 and 2 %) were significantly higher than those from control group. https://japu.gau.ac.ir/article_6998.html The aim of this research is to investigate the effects of different levels of dietary fulvic acid on systemic immunity, antioxidant capacity, and immune-antioxidant relative gene expression in zebrafish (Danio rerio). In order to investigate the effect of dietary fulvic acid (FLA), 600 healthy fish (average body weight 96.01 ± 3.01 mg) were randomly placed in 12 aquariums. During an experimental period of 8 weeks, fish was fed basal diets containing different levels of fulvic acid (0 (ctrl), 0.25 (FLA1), 0.5 (FLA2) and 1 (FLA3) g/kg diet) and they were fed three times a day. At the end of the experimental period, no significant difference was observed among experimental treatments regarding growth performance (P < 0.05). However, lysozyme activity, total immunoglobulin (Ig) and total protein of whole body extract were significantly increased in response to 0.5-1 g kg-1 diet fulvic acid compared to other treatments (P<0.05). However, no difference was observed among the experimental groups in terms of catalase, glutathione peroxidase and superoxide dismutase enzyme activities. The interferon-α (INF-α) and tumor necrosis factor alpha (TNF-α) genes expression increased in the treatments using fulvic acid, and the highest level was observed in 0.5 g/kg fulvic acid received treatment (P < 0.05). Also, the expression of interleukin 1 (IL-1) gene in this group was significantly increased compared to other experimental treatments (P<0.05). The expression of GPx gene was significantly increased in the group received fulvic acid without any significant difference among the treatments (P>0.05). CAT gene expression did not show any difference among experimental groups (P>0.05). Although SOD gene expression showed a significant increase in response to dietary fulvic acid, which the highest level was observed in the 0.5 g/kg received group (P < 0.05). In conclusion, according to the positive results obtained, fulvic acid can be potentially used as a feed additive in Zebrafish to boost growth performance and immnene performance and regulate anti-oxidant, and immune gene expression. https://japu.gau.ac.ir/article_7692.html Background and objectives: Almagol is an international wetland near the border of Iran and Turkmenistan, whose source of water supply is Etrak River. The geographical location, the long route of the supplying river and the low vegetation cover of the Turkmen Sahara area indicate the possibility of microplastic contamination in this wetland. The abundance, distribution and composition of microplastics in Almagal Lagoon was done for the first time in this study. Materials and methods: Water sampling was done in spring of 2023, in 5 stations. The separation of microplastics from the lagoon water was done by filtering method, so that for each repetition, one liter of lagoon water was taken by a vacuum pump. It was filtered on filter paper. A stereomicroscope was used to count the number of microplastics and to examine their appearance, and an infrared spectrometer was used for identification. Results: The results showed that microplastics were found in all 5 sampling stations and their average number was 40 pieces per liter. Station 5 (amusement park) showed the highest frequency of microplastic pollution with 46 pieces per liter. Microplastics with a size of 0.1-0.5 mm were the most abundant and most of the identified microplastics were fiber-shaped and black in color. The concentration of microplastics in the amusement park station is more than other stations due to the high traffic of local people and tourists and the dumping of garbage. Conclusion: This study highlights the importance of adequate waste management to limit microplastic pollution in recreational sites and ecologically important areas.Keywords: microplastic, Almagol lagoon, pollution, surface water https://japu.gau.ac.ir/article_7305.html Background and objectives: This study was designed to prevent Saprolegniasis (Saprolegnia parasitica) in rainbow trout (Oncorhynchus mykiss) eggs using laurel (Laurus nobilis) and Lawsonia Inermis L alcoholic essential oils. This research was completely practical and carried out in environmental conditions.Materials and methods: In this research, 3 treatments, each containing 3 concentrations, (9 treatments in total) were selected, and three trays with essential oils and two trays as controls with green malachite and pure water with temperature conditions of 13±2 degrees Celsius with a pH of 6.5-7.5 and a dissolved oxygen level of 6 ± 1 mg/liter for 18 days essential oils treatments are included 25, 50 and 70 mg/L and green malachite treatment is 3, 5 and 10 mg/L each with 3 repetitions by washing daily for 1 hour. Results: The results showed that the combined use of two essential oils of with dose of 70 mg/liter had 70% survival in the egg emergence stage and based on statistical data, it had a significant difference with the samples and doses of the control treatments.Conclusion: It can be concluded that the combined essential oils are suitable alternative to chemical disinfectants such as green malachite. https://japu.gau.ac.ir/article_7673.html The El Niño-Southern Oscillation (ENSO), a major ocean-atmospheric fluctuation in the Pacific Ocean, consists of two primary phases: El Niño (the warm phase) and La Niña (the cold phase). These two powerful phases, especially when severe, can have significant impacts on various economic and environmental sectors. From an aquaculture perspective, understanding the consequences of ENSO is crucial because the resulting climatic shifts directly affect aquatic production, aquatic animal health, and the overall sustainability of the aquaculture industry. El Niño, characterized by increased sea surface temperatures and altered rainfall patterns, can lead to reduced dissolved oxygen and changes in salinity. These conditions can stress farmed aquatic species and even result in mass mortalities. Additionally, El Niño can increase the prevalence of diseases; for instance, higher water temperatures can accelerate the growth and proliferation of pathogens while weakening the immune systems of aquatic animals. El Niño can also impact the production of plankton and other natural food sources upon which some farmed species depend. Conversely, La Niña, characterized by decreased sea surface temperatures and shifts in trade winds, can also present both challenges and opportunities for aquaculture. Changes in ocean current patterns and upwelling can affect the distribution of nutrients and the availability of food sources for certain species. On the other hand, more intense storms and heavy rainfall in some regions can damage aquaculture infrastructure and disrupt water quality. Overall, ENSO fluctuations, whether in the warm El Niño phase or the cold La Niña phase, can introduce considerable uncertainties for planning and operations within the aquaculture industry. Therefore, precise monitoring and the implementation of adaptive strategies including selecting resilient species, optimizing farm management practices, and developing early warning systems are essential to mitigate negative effects and ensure the industry's sustainability in the face of ENSO-induced climatic changes. https://japu.gau.ac.ir/article_7601.html Considering the importance and need of Fisheries organization in the direction of reproduction and breeding of cobia due to its high growth rate and the lack of comprehensive research on the biology of this fish in Iran, reproduction biology of cobia (Rachycentron canadum) were investigated from October 2021 to December 2022(12 months) in waters of Hormozgan province (northen part of Persian Gulf) from the western end (Javad Al-Aimeh port) to the eastern end (Gabrik port). The reproduction cycle, sexual maturity, sex ratio, Fecundity, Lm50 of cobia were studied from total of 509 specimens ranged from 19 to 159 cm fork length. Gonadosomatic index peaked during spring and summer with main peak in June. Spontaneous spawning occurs around the year with peak in June. The overall female to male ratio was significantly 1 : 1.49 (P<0.05). Batch fecundity were estimated 1684954±118990 in 15 females. Relationship between total length and fecundity were calculated F=1.3717TL 2.9567 (r2= 0.82). Females reached 50% sexual maturity at 81.25 cm FL. Due to the spawning time of this fish, it is suggested to ban fishing in cobia in the spring season in order to manage the catch. On the other hand, considering that this fish is native, it can be considered as a good candidate for the reproduction industry and then breeding fish in cages. https://japu.gau.ac.ir/article_7693.html Background and Objectives: This research was conducted with the aim of investigating the behavior of urban and rural consumers of farmed carp.Materials and Methods: After determining the assumptions and presenting an analytical-conceptual model based on the planned theory, a suitable questionnaire was designed and completed by a statistical sample in 3 provinces of the coastal line of the southern Caspian Sea. Then, using structural equation modeling (SEM), the intensity of the relationship between the research variables and the structure of the model, the state of accepting or rejecting the hypotheses was investigated. Results: The per capita consumption of fish among the consumers of farmed carp was 2.7 kg in urban and 4.6 kg in rural areas. The consumption of farmed carp was 0.5 kg in urban areas and 2.2 kg in rural areas. Conclusion: Since urban households do not perceive health risks associated with these fish, and rural households do not feel a commitment to consumption due to family dietary habits and awareness of farming methods, it is possible to influence their subjective norms through awareness. In any case, any awareness, considering the significant impact of experiential background, control strength, and control belief on the control of rural households' behavior, which does not lead to the final decision and consumption, can, alongside other effective factors, increase the consumption of farmed carp in rural areas, which have a higher capacity for accepting these fish. https://japu.gau.ac.ir/article_7603.html The effect different levels of astaxanthin on growth indices, food conversion ratio, immune system and antioxidant capacity of farmed female Huso huso broodstock was investigated.12 Huso huso (pre brood stock female, sexual maturation = II, average weight and length=16.16 kg ± 0.16 and 140.65 ± 13.2 cm) were fed by diet containing 50% protein, 14% lipid and 18 MJ/kg energy in Four treatments:C (without astaxanthin), C50, C100, C150 and C200 (50, 100, 150 and 200 mg/kg of astaxanthin) for 674 days.At the end of the breeding period, fish were in sexual stage III to IV and IV. fish fed with C200 had the highest final weight, body weight gain percentage, specific growth rate and the lowest food conversion ratio (P<0.05). lysozyme and immunoglobulin M in fish fed with C150 and C200 diets was significant higher than other treatments(P<0.05). Complement were increased by increasing of astaxanthin diet and highest Complement was recorded in fish fed C200 (P<0.05). total immunoglobulin in fish fed C100, C150 and C200 was significantly higher than C50 and C (P<0.05). A significant increase in superoxide dismutase (SOD), catalase (CAT) were revealed by increasing astaxanthin in diet, and highest amount was recorded in the fish fed by C200, while malondialdehyde (MDA) was opposite relationship with astaxanthin diet (P<0.05). The results of this study was revealed that a 200 mg/kg astaxanthin supplemetation led to growth indices increasing and improving immune system antioxidant capacity in Huso huso for brood stock stage. https://japu.gau.ac.ir/article_7694.html Background and objectives: The aim of this study was to produce liquid and solid biofertilizer from the green seaweed Chladophora glomerata enriched with chitosan and to investigate its effect on lettuce in terms of morphological indicators, photosynthetic pigments, anthocyanin, nitrate content and sensory evaluation. Material and methods: The green seaweed was dried and aqueous and alcoholic extracts were prepared from it. The aqueous extract showed higher levels of gibberellin by HPLC and was selected as the liquid algal fertilizer. The effects of five experimental groups (in three replicates) including the control group, the liquid fertilizer group (algae extract and algae extract + chitosan) and the solid fertilizer group (pure dry algae powder and wet algae powder remaining from extraction) were investigated in lettuce grown in a greenhouse. Results: In this study, the indices of crown height, plant fresh weight, root fresh weight, root length, chlorophyll a, chlorophyll b, total chlorophyll, anthocyanin and sensory characteristics (appearance, color, mouthfeel (taste), aroma and overall flavor) did not differ significantly among the different treatments. Conclusion: According to the results of the present study, the use of the aforementioned biofertilizers significantly reduced nitrate accumulation in cultivated lettuces, so that the lowest amount of this accumulation was in the treatment of lettuce fertilized with algae extract + chitosan. https://japu.gau.ac.ir/article_2235.html The Persian Gulf is one of the most important habitats of Pinctada radiata. The genetic information of this valuable species has largely remained unknown in the Persian Gulf. At the present study, 30 specimens were collected from the Hendourabi Island from the depths 8-10 m using SCUBA. The genetic structure of the specimens was examined. The highest and lowest gene diversity were 0.816 and 0.768, belonged to the loci M052 and M059, respectively. The highest and lowest inbreeding were found in loci M068 and M059, respectively. Number of allele and heterozygosity of the Hendourabi population were similar to other studies on other regions. Comparing the Hendourabi inbreeding with those of the other parts of the world showed that the Hendourabi inbreeding is higher than those reported for the other regions. Due to local extinction, the wide distribution of this species has reduced to smaller population nowadays. Occurrence of local extinction plus reduction of population size has decreased the genetic diversity and increased inbreeding of P. radiata populations. https://japu.gau.ac.ir/article_7695.html AbstractBackground and Objective: Sardines are small surface fish that have economic and ecological value in terms of producing fish powder and oil for human and non-human consumption.Materials and Methods: Changes in approximate composition (moisture, protein, fat, carbohydrate and ash) and fatty acid profile of sardine (Sardinella sindensis) were evaluated for one year, from April to March 2022.Results: The amount of protein, fat, carbohydrate and ash changes are from 15.59 to 22.8%, 4.2 to 10.2%, 0.42 to 0.87% and 1.85 to 3.1% respectively and have differences were significant (P<0.05). The fat content of sardine was high during the autumn to winter season (6.21-10.2 %) and the lowest fat content was reported in spring (May) (4.2 %). The amount of polyunsaturated fatty acids (PUFA) and total (EPA + DHA) in sardine oil was 32.343 and 8.241%, respectively, and the amount of sarcoplasmic, structural (myofibrillar) and connective (stroma) proteins was 22.95, respectively. It is 73.81 and 3.24 %. Conclusion: The results showed that there are no specific changes in protein, carbohydrate and ash content, while seasonal changes are more visible in the lipid content of the sample. The fat content increased from September and reached the maximum value (10.2%) in November, the changes in the fat of these fish were insignificant from December to March, and it decreased by 4.32% and 4.2% in April and May, respectively. https://japu.gau.ac.ir/article_7508.html AbstractBackground and objectives:Marine fish are crucial for global food security, providing high-quality protein, essential fatty acids, and micronutrients. Sardines, particularly the white sardine (Sardinella albella), are of significant economic and nutritional importance in Iran, constituting a major part of the catch in the Persian Gulf and Sea of Oman. However, as fatty fish, sardines are highly perishable due to their high levels of polyunsaturated fatty acids (PUFAs), which are susceptible to oxidative spoilage. This study aimed to evaluate the sensory, microbial, and chemical changes in white sardines stored in ice to determine their shelf life.Materials and methods:Fresh white sardine samples were obtained from the Masan fishery in Qeshm Island and transported to a laboratory under hygienic conditions. The fish were stored in ice, and their quality was assessed over time using sensory, microbial, and chemical evaluations. Sensory evaluation included examining the skin, flesh, gills, and eyes, with a total score below 4 indicating spoilage. Microbial analysis involved measuring total mesophilic and psychrophilic bacterial counts. Chemical assessments included pH, trimethylamine (TMA), total volatile basic nitrogen (TVB-N), free fatty acids (FFA), peroxide value (PV), and thiobarbituric acid reactive substances (TBARS).Results:The results showed a significant decline in sardine quality over the storage period. The total mesophilic and psychrophilic bacterial counts increased from 2.45 and 2.12 log cfu/g on day 0 to 8.14 and 8.86 log cfu/g by day 9, respectively (p<0.05). Sensory evaluation indicated that the fish reached the spoilage threshold (score < 4) between days 5 and 7. Chemically, the pH increased from 6.01 to 6.65, while TVB-N levels rose from 6.76 to 31.78 mg N/100 g (p<0.05). TMA content increased from 2.01 to 5.25 mg N/100 g, and FFA levels escalated from 2.45% to 12.43% (p<0.05). Oxidative spoilage was evident from the rise in PV (5.68 to 22.89 mEq O₂/kg fat) and TBARS (1.14 to 5.86 mg MDA/g) (p<0.05).Conclusion:The study concludes that white sardines are highly susceptible to spoilage due to their biochemical composition, leading to rapid microbial growth and oxidative deterioration. Despite storage in ice, quality degradation was observed across all measured indices. Based on the combined sensory, microbial, and chemical data, the shelf life of white sardines under ice storage was determined to be up to 7 days. These findings underscore the importance of implementing effective preservation strategies to maintain sardine quality and extend their shelf life. https://japu.gau.ac.ir/article_7696.html Lactic acid bacteria are part of the typical intestinal flora of many fish. The aim of this research was to isolate and identify lactic acid bacteria with probiotic potential from adult Caspian white fish. For this purpose, 30 pieces of adult white fish were caught from the Caspian Sea and sterile samples were taken from their intestines. The isolated lactic acid bacteria were isolated and purified by phenotypic (gram staining, biochemical tests) and molecular methods. Then these bacteria were evaluated based on salinity, pH, temperature and antibacterial activity against Aeromonas hydrophila and Yersinia ruckeri. Following specialized tests, including cultivation in a MacConkey, MRS medium, and various pH levels, this number was reduced to 9 confirmed strains. The probiotic potential of the remaining 9 bacteria was assessed at temperatures of 4, 20, and 40 °C, as well as at salinities of 1%, 2%, 3%, and 4%. Additionally, their antibacterial activity against A. hydrophila and Y. ruckeri were evaluated. Ultimately, after performing tests to evaluate probiotic potential, four isolates such as Aerococcus, Pediococcus pentosaceus (two isolates), and Lactococcus plantarum demonstrated the highest probiotic effectiveness compared to the other isolates. https://japu.gau.ac.ir/article_7164.html The study aimed to evaluate the socioeconomic status of local fishing communities in order to improve sustainable fishing management in the Mond and Dayyer-Nakhilo wetlands in 2021. Data were collected through 134 questionnaires and semi-structured interviews, including group discussions with native fishermen from these regions. The questionnaire targeted fishermen's demographics, characteristics of their vessels, fishing efforts, and the economics of fishing. The reliability of the questionnaire items was evaluated favorably (Cronbach's α = 0.785). Most of the participants in the research (70%) were between the ages of 35 and 55, and their education level ranged from primary to secondary school (65%). Fishing operations were mainly conducted by boats (92.5%), and fishing was the only source of livelihood for 87.3% of the fishermen. The impact of independent variables such as age and education level of fishermen on their responses to the targeted questions indicated that age had a positive correlation with variables such as willingness to cooperate with fisheries, compliance with regulations by non-native fishermen, and the impact of pollution on fishery (p<0.05). Additionally, age had a negative correlation with the variable of optimism towards the future of fishing in the region (p<0.05). Furthermore, the education level of fishermen had a negative correlation with variables such as satisfaction with the services provided by cooperatives and optimism towards the future of fishing in the region (p<0.05). On the other hand, education level had a positive correlation with the variable of compliance with regulations by native fishermen (p<0.05). The net income of most boat fishermen (56%) during the shrimp fishing season was less than 50 million Tomans. Additionally, 70% of the fishermen's maximum profit was 1.5 times higher than other seasons. These results can effectively inform the executive management of fisheries and the environment, allowing for decisions that reflect the reality of the target community and their effectiveness. https://japu.gau.ac.ir/article_7697.html Background and objectives: This study aimed to investigate the replacement of edible mealworms protein powder with fish protein powder in the diets of goldfish (Carassius auratus).Materials and methods: The experiment involved 5 different diet and was conducted with 3 repetitions, with initial weight of 29.84 ± 1.53 grams. Over a period of 60 days, the fish were fed by control, D25, D50, D75, and D100 diets, which contained 0%, 25%, 50%, 75%, and 100% replacement of the protein, respectively. The fish were fed approximately 5% of their body weight daily. At the end of the study, growth performance, blood parameters (RBC, WBC, hemoglobin, and hematocrit), liver enzyme activity (AST, ALT, and ALP), as well as plasma albumin and glucose levels were assessed.Results: The results indicated that there were no significant differences in growth performance across the different treatments (P>0.05). However, the highest final weight average, weight gain, and specific growth rate were found in the D50 (51.37±2.94 grams, 21.93±1.72 grams and 1.32±0.04%/d, respectively) treatment, while the D75 (3.74±0.14) treatment had the lowest feed conversion ratio. Hematological analysis revealed significant differences between the experimental treatments and the control group (P<0.05). Although there were no significant differences in plasma albumin levels among the experimental diets (P>0.05), treatments D25, D50, and D75 (6.87±1.14, 10.62±0.77 and 17.61±1.42 mg/dL, respectively) showed a significant reduction in plasma glucose levels compared to the control (24.23±2.86 mg/dL) group (P<0.05). There were no significant differences in AST enzyme activity among the treatments (P>0.05), but ALP activity was significantly higher in the experimental groups compared to the control (53.05±4.85 IU/L) group (P<0.05), with the highest level recorded in treatment D50 (93.08 ± 5.52 IU/L). Furthermore, ALT activity was significantly lower in the experimental groups than in the control (15.40±1.77 IU/L) group (P<0.05), with the lowest level observed in treatment D75 (2.21 ± 0.31 IU/L).Conclusion: Overall, the findings suggest that incorporating at least 25% edible mealworm powder into the diet of goldfish does not negatively impact feed intake, blood parameters, liver enzyme activity, or levels of glucose and albumin in plasma. This means it could serve as a viable alternative to fish meal. https://japu.gau.ac.ir/article_7698.html The family Nemacheilidae exhibits high species diversity in Iran, making it an ideal location to study the evolutionary processes that generate biodiversity. Oxynoemacheilus, a genus within the Nemacheilidae, has a distribution ranging from Albania to Iran and the Caucasus, with 16 species documented within Iran. This study investigates the genetic diversity and phylogenetic relationships among Oxynoemacheilus species in western Iran using mitochondrial cytochrome b gene sequences. Phylogenetic analysis was performed using Bayesian Inference (BI) and Maximum Likelihood (ML) methods. The results indicate that the examined species cluster into three distinct evolutionary lineages: O. elsae in Clade A; O. bergianus, O. euphraticus, O. longipinnis, and O. parvinae in Clade B as known as bergianus group; and O. chomanicus, O. frenatus, O. karunensis, O. kiabii, O. kurdistanicus, O. persa, O. zagrosensis, and O. zarzianus in Clade C. The findings suggest that O. elsae evolved independently, likely due to geographical separation from the other species studied. Additionally, robust body forms are observed exclusively in the Persian Gulf basin, whereas slender body forms are present across all three basins. These results contribute to understanding the evolutionary history and biogeographical distribution of Oxynoemacheilus species in Iran. https://japu.gau.ac.ir/article_7183.html The aim of this research is to use Streptomyces ambofaciens as a probiotic in the diet on growth indicators, intestinal digestive enzymes and blood indicators of grass carp juvenile (Ctenopharyngodon idella). During this research, 120 of grass carp juvenile with an average weight of 23.37 ±0.96 grams were kept for two weeks in the laboratory of the Fisheries Department of Zabol University to adapt to the nutritional and rearing conditions in 12 aquariums, 4 treatments and 3 replications. they were fed during 8 weeks with different levels (control, 105, 106 and 107 CFU/g) of Streptomyces ambofaciens. At the end of the experiment, the amount of growth and some indicators of nutrition were calculated, and the intestinal enzymes were measured by taking samples from the intestines of the fish. Results showed that Streptomyces ambofaciens had a positive effect on growth indicators so that weight gain (WG) and specific growth rate (SGR) in S2 and S3 treatments significantly increased and food conversion ratio (FCR) decreased compared to the control group. (P < 0.05).Also, the activity of intestinal protease and amylase increased significantly in the S2 and S3 treatments, while the lipase activity in the different treatments did not differ significantly. The number of white blood cells was significantly different between the control treatment and the treatment containing probiotics (P < 0.05). However, the number of red blood cells, hemoglobin and hematocrit was not significantly different between the control treatment and the treatments containing the probiotic Streptomyces ambophacines. In general, the results of this research showed that Streptomyces ambofacines bacterium improves the growth and feeding indicators of grass carp juvenile by increasing the activity of intestinal protease and amylase digestive enzymes, as well as increasing the number of white blood cells and thus improving non-specific immunity. https://japu.gau.ac.ir/article_7699.html AbstractBackground and Objective: The aim of this study was to determine the effect of a mixture of the antibiotics amoxicillin, ceftriaxone, and ciprofloxacin on reducing the incidence of deformities, regurgitation, and mortality in the eastern leech from larval-needle size to cosmetic-medical size.Materials and Methods: In this study, 360 eastern leeches were divided into 12 ten-liter containers, each containing four liters of water. Four experimental treatments with three replicates each were compared: the control group, Treatment 1 receiving a mixture of ceftriaxone, amoxicillin, and ciprofloxacin at a concentration of 21.69 mg/L; Treatment 2 receiving 31.98 mg/L; and Treatment 3 receiving 41.86 mg/L of the antibiotic mixture.Results:Observation of blood regurgitation in leeches showed no regurgitation in any of the treatments during the first feeding phase. In the second feeding phase, the control group exhibited significantly more regurgitation events (18 times, p<0.05). In the third feeding phase, Treatments 1 and 3 had equal regurgitation frequencies with no significant difference observed between them (p>0.05).Conclusion:These findings clearly indicate the effectiveness of the antibiotic mixture (ceftriaxone, ciprofloxacin, and amoxicillin) in reducing deformities, regurgitation, and mortality after blood feeding in eastern leeches at various developmental stages (larval, needle, matchstick, cosmetic, and medical sizes).Keywords: Hirudo orientalis; eastern leech; antibiotic; deformity; regurgitation; ciprofloxacin; amoxicillin; ceftriaxone https://japu.gau.ac.ir/article_7700.html During the surimi production process, a significant portion of the healthy fats present in fish meat is removed, leading to a reduction in its nutritional value. While unsaturated fats provide health benefits, their direct addition can negatively impact the final product's texture. This study focused on developing emulsion-based oleogels (Emugel) with fish gelatin (FG) and κ-carrageenan (KC) to assess their effects on the color and texture of surimi. The sample containing the mixture of free salmon oil and olive oil (non-emulsified) was considered the positive control, whereas the sample without oil (free/Emugel) served as the negative control. Based on the results, Emugels increased the whiteness in the surimi paste and gel compared to the control sample (P<0.05). The addition of KC to FG enhanced the gel properties and thermal stability of the emogel. Additionally, Emugels exhibited positive effects on the rheological properties of surimi paste compared to the positive control, indicating that the Emogels could compensate for the negative effect of free oil on the gel structure. The hardness of surimi gels containing oil (free/Emugel) was lower compared to the negative control (P<0.05). No significant difference was observed in the springiness and water holding capacity (WHC) of the samples (P>0.05). Overall, the results indicate that the Emugels based on FG and KC can be used as a substitute for liquid oil in surimi formulations while maintaining the desired quality and rheological properties of the product. These findings can aid in producing seafood products with higher nutritional value and improved sensory properties. https://japu.gau.ac.ir/article_7701.html Ultrasound and microwave are new technologies that have recently been widely used to perform hydrolysis. The aim of this study is to investigate the effect of modern ultrasound and microwave technologies on the properties of hydrolyzed protein of the microalgae Chlorella vulgaris. For this purpose, the microalgae Chlorella vulgaris was hydrolyzed with alcalase enzyme (temperature 50 ° C, concentration 100 mg enzyme, pH = 8, for four hours) under ultrasound waves (70 W for 10 minutes) and microwave (90 ° C for 10 minutes). The results showed that the protein content with a value of (59.67 ± 0.12%) in the algae Chlorella vulgaris has the highest level. Among the chemical compositions of protein hydrolysate, the highest protein content was related to protein hydrolyzed with ultrasound with a value of (89.19±0.24%) (p<0.05) and the highest moisture, ash and fat content was related to enzymatic hydrolysis with values of 3.8±0.73, 8.2±0.22 and 14.37±0.07%, respectively (p<0.05). The degree of hydrolysis increased with the use of microwave and ultrasound and the highest value was related to ultrasound hydrolysis with 37.98±0.76% (p<0.05). The antioxidant performance was also improved by using pretreatment, such that the ultrasound hydrolyzed sample showed the highest value at all concentrations (p<0.05). The highest IC50 values of DPPH and ABTS radical scavenging power in ultrasound treatment were 0.22 ± 0.01 and 0.32 ± 0.02 mg/mL, respectively (p<0.05). In general, the results showed that the use of modern methods such as microwave and ultrasound can improve the antioxidant performance of Chlorella vulgaris algae hydrolysate. https://japu.gau.ac.ir/article_7702.html Discharge of fish farm untreated effluent can be one of the point source pollution and effective in changing the structure of the benthic macroinvertebrates of rivers. Therefore, the benthic macroinvertebrates of the Azad river were sampled to determine its population structure during 3 sampling periods in spring (low density farming), summer (high density), and autumn (medium density) 2023 at 3 stations including 1) upstream or control station, 2) farm effluent outlet, and 3) from distance of 650 meters after the fish farm. In present study, 22 taxa belonging to 9 orders and 6 phyla were identified overall. The Baetidae and Gammaridae had the highest abundance with %41.19 and %22.06 respectively and some taxa such as Chironomidae, Tubificidae, Simuliidae, and Naididae were in the next ranks. determining the abundance of benthic macroinvertebrates showed that the difference was significant only among different seasons, so that the highest abundance was obtained in summer and autumn (p<0.05), among which Baetidae in autumn, Gammaridae in summer and Chironomidae in spring had the highest percentage of abundance. Although spatial changes were not significant, but the trend from station 1 to station 3 was increasing. In general, the results of the present study showed that the footprint of the effects of fish farm effluent on the distribution and structure of benthic communities was relatively clear, since its abundance increased significantly in summer and at downstream stations with the highest aquaculture effects simultaneously. https://japu.gau.ac.ir/article_7703.html Background and objectives: The aim of this study was to investigate the effect of adding cottonseed meal and a mixture of organic acids to the diet on hematological characteristics, blood electrolytes, histopathology, and antioxidant activity in the liver of rainbow trout. Materials and methods: To this, six treatments consisting of six diets with three replications were designed in a factorial design of 3 × 2. In this design, two levels of cottonseed meal (0% and 15%) and three levels of a mixture of organic acids (lactic acid, citric acid, and potassium sorbate in equal proportions) at 0%, 0.5%, and 1% were added to the diet. A total of 270 rainbow trout with an average weight of 14.0 ± 0.35 g were stocked in 18 aquaria containing 40 L water, with a density of 15 fish per aquarium. The above diets were provided to the fish for 8 weeks at a rate of 3 to 4% of their biomass daily. After 8 weeks of rearing, blood and liver samples were taken from all treatments. Results: Cottonseed meal and organic acids had no significant effect on hematological parameters except for MCHC, where the addition of cottonseed meal to the diet reduced MCHC. Additionally, cottonseed meal and organic acids did not significantly affect plasma alanine aminotransferase, aspartate aminotransferase and calcium, hepatic superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione and malondialdehyde, or liver histopathology. The addition of organic acids to the diet increased plasma phosphorus and iron levels, while adding cottonseed meal increased glutathione reductase activity in the liver. Conclusion: The results of this study indicated that the addition of 15% cottonseed meal to the diet of rainbow trout fingerling has no negative effects on liver histopathology or antioxidant status but does lead to hypochromic anemia. Furthermore, the addition of organic acids likely increased the bioavailability of phosphorus and iron in the diet. However, the long-term effects of anemia and the potential of organic acids to improve hematopoiesis and phosphorus retention in the body should be explored in future studies. https://japu.gau.ac.ir/article_7705.html To assess the biodiversity (abundance and species richness) of aquatic macroinvertebrates in the Baghou Stream in the Gorgan Gulf basin, southeastern Caspian Sea, seven monthly sampling surveys were conducted from November 2022 to May 2023 in four sampling sites with three replicates at each site using a surber-sampler (30*30 cm). The results showed that 14 taxa of macroinvertebrates were identified in the level of family (including 4 orders of insects and one order of oligochaetes). Three families including Chironomidae (43.5%), Simuliidae (19.7%), and Beatidae (14.2%) had the highest abundance. The abundance of aquatic macro-invertebrates did not differ significantly in the winter and spring months (p>0.05). Also, the abundance of aquatic macroinvertebrates at site 1 was higher than the other sites. Chironomidae and Simuliidae had higher abundance in winter, while the abundance of Baetidae increased in spring. The rainfall occurred before the 7th (last) sampling event in the Gorgan Bay basin decreased the abundance of Chironomidae and Simuliidae, and increased the abundance of Tubificidae at site 1. Also, the abundance of Baetidae decreased at the forest sites. When the water flow in Baghou stream was uniform and calm, the abundance of aquatic macroinvertebrates did not change; while occurring rainfall and increasing water flow in the streams, although it changed the dominant aquatic species, but it did not generally change the abundance of aquatic macroinvertebrates. This study highlights the importance of maintaining uniform water flow in streams and rivers (maintaining the water balance of aquatic ecosystems) in maintaining biodiversity and maintaining the abundance of aquatic animals. https://japu.gau.ac.ir/article_7141.html The present study was aimed to assess spatial variation of the catch composition and catch rate of Gargoor trap fishery in the Beris fishing grounds, Sistan and Baluchistan province, between September and March 2021. Thirty Gargoors’ fishing operation in two depth strata, (1) average depth (±SD) of 28 (±2.04) m; 12 No. (2) average depth (±SD) of 52 (±1.48) m; 18 No., were monitored weekly. Despite that mean CPUE (± S.E.) of Gargoors in the depths of 30 and 50 m were computed at 2892±658.57 and 3257±501.24 g. garoor-1. week-1, there was no significant difference between them (P>0.05). Moreover, catch rate based on the number of specimens caught, was differed between the groups (P<0.05). The catch composition of the Gargoors located in the depth of 28 m included 5 species which Lutjanus johnii and Heniochus acuminatus had the maximum and minimum weighted abundance and Argyrops filamentosus and Caranx heberi had the highest and lowest numerical abundance. As well, 12 species were captured by the Gargoors in the depth of 52 m which Caranx heberi and Abalistes stellaris had the maximum and minimum weighted abundance and Scomberoides commersonnianus had highest numerical abundance. Results of nMDS and ANOSIM statistical tests indicated a weak dissimilarity between the catch composition of Gargoors in the two studied depth stratums. https://japu.gau.ac.ir/article_7708.html Background and Objective: One of the new theories is the control of microorganisms using a self-control mechanism, which is carried out through bacterial signaling metabolites via the quorum sensing process. The aim of this study was to produce nanocapsules containing bacterial supernatant capable of controlled release according to environmental needs to manage bacterial contamination.Materials and Methods: according to the results, nanocapsules containing the specific supernatant of lactic acid bacteria, produced during the logarithmic growth phase and the death phase, were prepared. The inhibitory properties of these substances against Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Bacillus cereus were evaluated using the MIC method. Eventually, the most effective encapsulated supernatant composition was selected against the target bacteria. The expression of a specific virulence gene in L. monocytogenes was assessed using real-time PCR. Various characteristics of the nanocapsules, including structure, stability, encapsulation efficiency, and other relevant parameters, were examined. The obtained data were statistically analyzed using SPSS software.Results: The results showed that the supernatant from lactic acid bacteria in the death phase had the greatest inhibitory effect on the growth of E. coli, S. aureus, Bacillus cereus, and L. monocytogenes (P < 0.05). Additionally, the duration of effectiveness of the encapsulated supernatant was significantly longer than that of the non-encapsulated supernatant. Gene expression analysis of L. monocytogenes revealed that the virulence gene hly was significantly reduced under these conditions but was still expressed.Conclusion: From the obtained results, it can be concluded that the bacterial supernatant contains metabolites capable of controlling microbial growth and reducing it. However, it does not have an effect on controlling the expression of bacterial virulence genes. https://japu.gau.ac.ir/article_7704.html Due to the drought and severe reduction of water resources, deep wells were dug in the Sistan region for the first time. Currently, the water is extracted from the deep well No. 3 located in Nimrooz city, is used for salmon cultivation on an experimental basis. Therefore, the concentration of heavy metals in the edible tissue was measured. Cadmium (Cd), chromium (Cr), arsenic (As), nickel (Ni), lead (Pb), and mercury (Hg) were considered in the edible tissue of salmon. Cultivated and juvenile fish were collected along with fish feed and water samples were taken in two stages from the experimental pond close to the deep well No. 3. For measure the concentration of the studied metals, ICP-MS device was utilized. The concentrations of some heavy metals in water were lower than standard values. The metal concentrations in food samples were higher than those in the fish tissues, whereas no significant difference was detected between the juvenile and cultivated fish muscles. The average concentrations of arsenic and chromium in cultivated fish muscles were 4.05 and 5.10, 0.22 and 0.25 μg/g dw, with no significant differences between the two groups. The nickel concentrations in two groups of cultivated fishes were 0.085 and 0.07 μg/g dw and lead were 0.166 and 0.3 μg/g dw respectively, with no significant difference. The comparison of the metal concentration in the edible tissue of different weight groups of fish did not show any significant difference. As a result, the continuation of the breeding period to gain more fish weight does not affect the increase of heavy metals in salmon muscle. https://japu.gau.ac.ir/article_7706.html In recent years, the encircling gillnet fishing method has attracted the attention of Chabahar fishers due to its higher catch of target species and greater total yield compared to conventional gillnets. The present study aimed to investigate the catch composition, length frequency, illegal catch, catch per unit effort (CPUE), and the effects of environmental factors on the catches of encircling gillnets in the Chabahar fishing grounds. A total of 817 fish specimens were caught using encircling gillnets. The results indicated that the highest catch belonged to yellowfin tuna (Thunnus albacares; Bonnaterre, 1788), comprising 42.23% of the total catch, while the lowest catch corresponded to yellowtail barracuda (Sphyraena jello; Cuvier, 1829) at 8.08%. Analysis of the length frequency of the captured fish revealed the following mean lengths (± SD): yellowfin tuna (Thunnus albacares; Bonnaterre, 1788), 72.42 ± 6.31 cm; common hoover (Thunnus tonggol; Bleeker, 1851), 52.74 ± 5.18 cm; blacktail barracuda (Sphyraena putnamae; Jordan & Seale, 1905), 53.21 ± 6.16 cm; kingfish (Scomberomorus commerson; Lacepede, 1800), 83.25 ± 4.27 cm; and yellowtail barracuda (Sphyraena jello; Cuvier, 1829), 85.32 ± 3.29 cm. Additionally, the results showed that neither season nor temperature had a significant effect on the CPUE of encircling gillnets, whereas depth had a direct influence on their catch rates. Based on the findings, the performance of encircling gillnets in terms of catch efficiency was deemed satisfactory, and with proper mesh size regulation, these nets could be effectively utilized in the region. https://japu.gau.ac.ir/article_7691.html Recycling fishery wastes through a fermentation process generates added value by converting these discarded resources into a valuable protein source. To enhance the value of rainbow trout (Oncorhynchus mykiss) waste, the materials were fermented using two bacterial strains, Bacillus subtilis and Lactobacillus plantarum, and subsequently utilized as a protein source to replace fish meal at inclusion levels of 30%, 40%, and 50% in the diet of Nile tilapia (Oreochromis niloticus). Protein quality and chemical composition of the fermented silage and formulated diets were analyzed in the first phase of this study, while growth performance indices and digestive enzyme activities of Nile tilapia fed these diets for 56 days were evaluated in the second phase. Results showed that the fermented silage contained crude protein and lipid levels of 34.83% and 25.77%, respectively, with a total energy content of 1839 kJ per 100 g. The contents of all essential amino acids in the fermented silage were significantly lower than those in fish meal (p ≤ 0.05). The best growth performance, including final body weight (59.29 g), specific growth rate (1.90%), and optimal feed conversion ratio (3.08), was obtained from diets containing 30% fermented silage. Diets with 40% fermented silage exhibited the highest protease activity. In conclusion, the fermented silage produced from rainbow trout waste can replace up to 30% of fish meal in Nile tilapia diets without adverse effects on growth performance or digestive physiology. https://japu.gau.ac.ir/article_7718.html Background and objectives: This study evaluated the effects of an aquamimicry system on growth performance, water quality, and economic efficiency of dense Litopenaeus vannamei culture in Gomishan (Golestan Province).Materials and methods: Shrimp post-larvae (PL12) were stocked at 20 per m² for 120 days. Two treatments were compared: control (TC: traditional method with commercial feed and water exchange) and aquamimicry (TA: 16 kg fermented rice bran + 14 L probiotics, with 20% water exchange). Water physicochemical parameters, growth performance, plankton abundance, and economic indices were analyzed using t-test (p < 0.05).Results: Dissolved oxygen was more stable in TA (6.5 vs. 6.2 mg/L). pH was stable in TA (7.6-8.1) but increased in TC (7.2-8.5). TSS increased in TC but decreased in TA. Growth performance was significantly higher in TA (p < 0.05). Feed conversion ratio improved in TA (1.26 vs. 1.51) and total biomass increased by 44.4%. Production cost per kg of shrimp was 25.4% lower in TA.Conclusion: The aquamimicry system improves production efficiency, reduces environmental impacts, and increases economic returns, offering a sustainable alternative for L. vannamei farming in Gomishan. https://japu.gau.ac.ir/article_7720.html Modern aquaculture faces fundamental challenges in the efficient distribution of feed and the management of solid waste, both of which directly impact water quality and fish health. Moreover, inadequate pond hydrodynamics result in low hydraulic efficiency, the formation of dead zones, and flow short-circuiting, all of which disrupt the distribution of oxygen and nutrients. Octagonal ponds have been recognized as effective solutions for optimizing high-density fish culture due to their favorable mixing characteristics and self-cleaning capabilities.This study employed laboratory-scale modeling to investigate the influence of submerged inlet configurations on hydraulic efficiency and feed residence time distribution in octagonal ponds. Five different inlet configurations (β1 to β5), representing uniform and non-uniform flow velocity distributions at various depths, were examined. Results indicated that β1, characterized by the lowest inlet velocity, and β4, with a decreasing velocity profile, exhibited poor to moderate hydraulic efficiencies (below 50%). Configuration β2 demonstrated moderate efficiency (approximately 60%). Configurations β3 and β5 achieved high efficiencies of 85% and 75%, respectively, suggesting a significant reduction in dead zones. Additionally, β3 and β5 showed the lowest feed residue levels, underscoring their effectiveness in managing feed residence time.These findings offer practical insights for optimizing inlet system design, ultimately enhancing the productivity and sustainability of aquaculture operations