A. Irani , N. Agh,
Volume 8, Issue 1 (3-2019)
Abstract
Aims: In this research, we investigated the effects of stocking density on growth performance and survival rate of Persian sturgeon and Beluga.
Materials and Methods: Stocking densities for treatments 1-5 of Persian sturgeon in stages 1 were 6, 8, 10, 12 and 14 fish/l (initial weight: 116mg) and in stage 2 were 1, 2, 3, 4 and 5 fish/l (initial weight: 2218/6mg). Stocking densities of five months old Beluga juveniles (initial weight: 109.95g) for treatments 1-5 were 80, 100, 120, 140 and 160 fish/m3 in each 250-liter tank respectively.
Findings: Growth and feeding parameters were affected as the stocking densities increased in both species. In stage 1 in terms of weight, SGR and food efficiency, treatments 1 and 2 showed significantly higher values (p<0.05) comparing with treatment 5, treatments 4 and 5 and all treatments respectively. In stage 2, there are significant differences amongst the all treatments in terms of weight and SGR except treatments 3 and 4. Food efficiency in treatment 1 was significantly higher (p<0.05) than the rests except treatment 2. In Beluga, there were significant differences amongst all treatments except treatments 3 and 4 in terms of weight, SGR, and food efficiency and the highest values were observed in treatment 1.
Conclusion: The best stocking densities for stage 1 and 2 of Persian sturgeon were 8-10 and 1-2 fish/l respectively and for Beluga, juveniles were 80-100 fish/m3.
Z. Ghaderi , B. Falahatkar, H. Allaf Noveirian , A. Rahdari ,
Volume 8, Issue 1 (3-2019)
Abstract
The aim of the present study was to investigate the effects of ascorbic acid and density on reproductive performance and steroid hormones in rainbow trout (Oncorhynchus mykiss). In this regard, six treatments were considered included three diets containing 0, 100, and 1000mg ascorbic acid as L-ascorbyl-2-polyphosphate per kilogram of food in contrast to two densities 4.33kg/m3 and 2.16kg/m3. Triplicate groups of fish were fed one of the test diets for 16 weeks. A total of 81 females with an average weight of 812.1±1.5g were introduced to tanks (910 liters). At the end of the 16th week and when preparing fish for spawning, from each replication of high and low densities, 4 and 2 fish after bleeding of fish to measure the concentrations of progesterone, testosterone, and estradiol were spawned. After that, reproductive parameters such as work fecundity, ova per gram, and ova diameter were measured and then fertilized. During the incubation period, fertilization and mortality rates were recorded. The results showed the interaction between ascorbic acid and density and also the significance of this effect in reproductive parameters (number per gram of egg, oocyte diameter, coagulation, and fertilization percent; p<0.05). In the case of steroid hormones, the effect of treatments on the amount of each of the three hormones and their interaction on the level of estradiol and testosterone were significant (p<0.05), but the effect of density and diet on progesterone was not significant (p>0.05). The results of this study confirm the use of higher levels of ascorbic acid in breeders compared to grow-out period and also the positive role of this vitamin in reproductive indices.
Abdoljabbar Irani, Naser Agh,
Volume 8, Issue 2 (5-2019)
Abstract
Aims: Due to vital role of optimum feeding rate on success and profitability of an aquaculture practice, feeding rates were examined in different life stages of Beluga sturgeon.
Methods: Feeding rates were 5%, 7%, 9%, 11%, 13% and 15% in stage 1; 2%, 4%, 6%, 8%, 10% and 12% in stage 2; 1.5%, 2%, 2.5%, 3% and 3.5% in stage 3; 1.5%, 1.75%, 2%, 2.25% and 2.5% in stage 4. Farming durations of stages 1 to 4 were 10, 10, 42 and 56 days, as well as initial mean weights were 1.85, 7, 112.04 and 300.54 g, respectively.
Findings: Results showed that optimum feeding rates from growth and feeding parameters point of view were 9% and 5%, respectively, in stage 1. In stage 2 also optimum feeding rates were different from growth and feeding point of view, as they were 4% and 2%, respectively. For both aspects of growth and feeding parameters, optimum feeding rate was 2.5% of body weight in stage 3. In stage 4, the lowest food conversion rate was observed in the feeding rate of 1.5% and there were no significant differences between treatments from growth parameters point of view.
Conclusion: Growth and feeding parameters were affected with feeding rates in stages 1, 2 and 3. In stage 4, feeding rates influenced feeding parameters, but had no significant effects on growth performance.
Mohammad Harsij, Hossein Adineh, Rasool Maleknejad, Hojatollah Jafariyan, Mehdi Asadi,
Volume 8, Issue 3 (9-2019)
Abstract
Aims: The present study investigated the effects of different levels using of mealworm (Tenebrio molitor L., TM) on the growth and feed performance, body composition and digestive enzymes of rainbow trout, Oncorhynchus mykiss.
Materials & Methods: Fish (8.58± 0.27 g) in a completely randomized design in 4 treatments and each with 3 replications. Rainbow trout with different levels of 0, 15, 30 and 60% diet (TM0, TM15, TM30 and TM60) (including 50% moisture) of live worm for 30 days. Data were analyzed by one-way (SPSS 17). When p values were significant (P<0.05), means were compared using Duncan's multiple-range test.
Findings: At the end of the experimental, there were significant difference between treatments in growth performance and feed utilization. The results revealed that fish growth parameters and efficiency of nutrient utilization tended to increase with increasing dietary TM levels from 0 to 60%. Feed Conversion Ratio (FCR) was significantly reduced in fish fed the diet with the highest worm level (TM60). The treatments fed TM showed highest protein and lower lipid content compared to fish fed control diet.
The analysis of gastrointestinal enzymes showed that amylase, protease and lipase had a statistically significant difference between the control and other treatments. Protease and amylase activities were found to be significantly higher for fish fed the TM60 diet compared with fish fed TM0 diet.
Conclusion: The results showed that using 60% (TM60) of worm instead of the base diet can improve growth, carcass composition and digestive enzymes.
Neda Mirhosseini, Reza Davarnejad, Ahmad Hallajisani, Edgar Cano-Europa, Omid Tavakoli,
Volume 8, Issue 4 (10-2019)
Abstract
Aims: microalgae use has been recently attracted for the production of biologically active drugs and pharmaceuticals.Carbon source is an essential factor for the Spirulina maxima growth. Since finding the appropriate carbon source and its concentration to achieve high levels of biomass in the shortest cultivation period is very valuable. Therefore, the effect of different carbon sources (sodium carbonate, sodium bicarbonate, glucose and molasses) with different concentrations (16, 24 and 32 gL-1) on growth and biomass production were evaluated. Methods: Microalgae was grown in 11 treatments with 3 replications at labarotary temperature (28±3 °C) and 1350±100 Lux light intensity (24 hours exposure-time). Maximum specific growth rate and doubling time were calculated according to nonlinear modeling by Wolfram Mathematica software at 99% confidence interval. Findings: The highest biomass concentration (gL-1) at the highest carbon source concentration in the first 5 days belonged to molasses (3.083), glucose (2.094), sodium carbonate (0.869) and sodium bicarbonate (0.835). Biomass production of treatments except glucose in medium was increased by increasing concentration from 16 to 32 gL-1. Although molasses has reached on highest biomass production during the first 5 days of cultivation, but the greatest effect on increasing specific growth rate belongs to the glucose sample. Conclusions: As a result, the carbon source and its concentration had a significant effect on the growth and biomass production. Glucose has been selected as an effective carbon source for growth with a concentration of 24gL-1. Moreover, the highest concentration of treatments had shown the least effect on specific growth rate.
Maryam Amiri Resketi, Sakineh Yeganeh, Khosrow Jani Khalili,
Volume 9, Issue 1 (1-2020)
Abstract
Aims: The aim of this study was to investigate the effect of dietary lemon peel (Citrus limon) essential oil on growth, hematological parameters, some of serum biochemical parameters and liver enzymes in rainbow trout (Oncorhynchus mykiss) juveniles. Materials & Methods: For this purpose, 144 rainbow trouts with an average initial weight of 95.05 ± 0.41 g were randomly stocked in four treatments containing different levels of lemon peel essential oil ( 0 (control), 200, 400 and 600 mg lemon peel essential oil/kg diet) and fed for eight weeks. Findings: The results showed the highest growth factors in treatments of 400 and 600 mg lemon peel essential oil/kg diet (p<0.05). Inclusion of essential oil in diet increased hematological parameters as compared to the control except MCV, MCH, MCHC and increased serum biochemical parameters by contrast to the control except glucose, triglyseride and cortisol (p<0.05). liver enzymes of ALT and AST showed no significant differences among treatments containing essential oil and LDH exhibited no significant differences among 400, 600 mg essential oil/kg diet and the control treatment (p>0.05), but ALP amount significantly increased in essential oil treatments in a comparison to the control (p<0.05). Conclusion: Overall, these results indicated using 400 mg essential oil in rainbow trout diet could improve growth, hematological and some serum biochemical parameters of rainbow trout without any negative effects on liver.
Afshin Adeli, Siamak Yousefi Siakalroudi,
Volume 10, Issue 4 (12-2021)
Abstract
Government support for attracting investment in Persian Gulf marine fish farming has provided the grounds for Iran's fisheries development. Sea bass is a valuable species in the global market that, while helping food security and exports, also brings offshore security to the country by farming in marine cages. Production of more than 26,000 tons in the five years leading up to 2019 and its 45% growth in southern Iran promises more success for it. The study reviews Iran's position in the production of Sea bass fish in the southern waters of the country and identifies its strengths, weaknesses, and opportunities and threats. Therefore, with self-sufficiency in the supply of fry and inputs, strengthening training and research in the field of marine fish, organizing the internal market and continuous monitoring of the international market, monitoring pollution and its environmental impact assessment and developing the support chain of related industries before and after Will be able to provide sustainable development.
Sara Pourhosein Sarameh, Bahram Falahatkar,
Volume 10, Issue 4 (12-2021)
Abstract
Targets:The objective of this study was to control the reproductive cycle and increasing the efficiency of the production of pikeperch (Sander lucioperca) through determining the effects of different photoperiods on reproductive performance and egg and larval quality.
Methods: Pikeperch broodstock with mean weights 1367 ± 55.3 g were exposed to three different photoperiods with light intensity 630 lux including constant light (24L), constant darkness (24D), and 12 h of light, 12 h of darkness (12L:12D) with three replicates for 40 days.
Results: The results showed that the pikeperch reproductive performance was affected by photoperiod. Broodstock under 24L spawned earlier than those of the other photoperiods. The highest spawning were observed in the morning in 24L (66.7 ± 3.5%) and the lowest spawning belonged to the 24D and 12L:12D that never spawned at night. Although fertilization rate and number of eggs per gram did not show any significant difference in various photoperiods, the timing of spawning and the egg quality exhibited remarkable difference.
Conclusion: The results of this study pointed out to effective application of photoperiod on changing the spawning time, reproductive and induction of out-of-season spawning of pikeperch broodstock. Additionally, these results unequivocally prove that the reproductive performance of pikeperch can be considerably improved and stimulated by an effective photoperiod.
Ahmad Ahmadi, Nasrollah Ahmadifard, Ahmad Imani, Sajad Pirsa, Behrooz Atashbar,
Volume 10, Issue 4 (12-2021)
Abstract
In the present study, the effect of phytohormone gibberellin on some physiological parameters of Tetraselmis suecica microalgae was investigated. Algae culture was performed under standard conditions with Gillard culture medium, temperature 25 ± 2 C°, light intensity 16: 8 (light/dark), salinity 25 ± 2 mg / l, and 24-hour aeration for ten days. Concentrations of 10, 20, 40, and 60 mg / l were added to the algae culture medium. Growth factors, pigments, photosynthetic factors, and biochemical composition were measured in the log phase. Based on results, the highest rate of cell growth was observed in the treatment of 60 mg / l, although in other treatments there was a significant difference with the control (P <0.05). The highest amount of protein and carbohydrates was observed in the treatment of 60 mg / l (P <0.05). ). Total lipid content increased from 15.23 in control to 18.53 in 60 mg / l (P <0.05). Antioxidant potential, pigments, photosynthetic factors, and dry weight also showed a significant difference in the concentration of 60 mg / l compared to the control (P <0.05). The highest amount of chlorophyll a and chlorophyll b was observed at concentrations of 60 mg / l (P <0.05). Based on the results, gibberellin has a high potential for cell division, final density, antioxidant potential, cell size, and biochemical composition of Tetraselmis suecica. Also, Tetraselmis suecica can be a good candidate for marine aquatic larvae, drugs, antioxidants, and a rich source of compounds in biofuels.
Gholamali Akbarzadeh Chomachaei, Shiva Aghajary Khazaei, Siamak Darvishi, Siyamak Behzadi, Ramin Karimzadeh,
Volume 10, Issue 4 (12-2021)
Abstract
This study was conducted to investigate the possible effects of cages culture Asian sea bass fish (Lates calcarifer) on the population structure of macrobenthos in the Rigo area of Qeshm Island in Hormozgan province during a breeding period in 1397 were investigated. The average abundance of macrobenthos at the location of the cages culture and the refrences site in this study was equal to (52765 ± 19154 in m2) and (50642 ± 21002 in m2), respectively.The results showed that at the time of the study among the identified the genus of Ammonia sp. With a relative abundance of 73.41 percent at the location of the cages compared to the control station and Archasterope sp., Spirolochulina sp. and Nephtys sp. with a relative abundance of 63.9%, 49.1% and 12.6%, respectively, were more dominant in the control station compared to the location of the cages.The loading rate of organic matter in the bed of the cages was significantly affected by fish farming activities and in some times showed a significant difference with the control station (P<0.05). In general, at the time of the study, activities related to fish farming in cages had no effect on the population structure of macrobenthos in the study area.
Mina Jalali, Nemat Mahmoudi, Alireza Fallah Nosratabad,
Volume 10, Issue 4 (12-2021)
Abstract
The aim of the present study was to investigate the possibility of replacing phosphorus chemical fertilizer (triple superphosphate) with biofertilizers as an environmentally friendly approach. In this study, Possibility of replacing Triple superphosphate fertilizer with phosphate solubilizing bacteria "Pseudomonas deceptionensis Persian10 strain" in 10 treatments with two bacterial factors (in two levels of inoculation and non-inoculation) and chemical fertilizer (in five levels 0, 25, 50, 75 and 100% of the recommended amount of fertilizer in the pond) was examined in aquarium conditions. Treatments included: 1: 100% fertilizer + bacteria, 2: bacteria, 3: 25% fertilizer + bacteria, 4: 50% fertilizer + bacteria, 5: 75% fertilizer + bacteria, 6: 100% fertilizer, 7: 75% fertilizer, 8: 50% fertilizer, 9: 25% fertilizer, 10: control (without fertilizer and bacteria). Bacterial densities, soluble phosphorus, phosphatase and pH were measured on days 0, 2, 7, 12 and 17. The results showed that the phosphorus of all treatments had an increasing trend on different days and at the same time, an increase in the pH value and a decreasing trend was observed in the bacterial population and the amount of phosphatase enzyme. The highest amount of soluble phosphorus was observed in treatments 4 and 5. According to the obtained results, the application of 50% phosphate fertilizer + phosphate solubilizing bacteria can be recommended as a suitable ratio for the fertility of fish ponds and reducing the use of chemical fertilizers.
Zahra Mahmoudi, Mohammad Kazemian, Eghbal Khajehrahimi,
Volume 11, Issue 1 (3-2022)
Abstract
The long nose sturgeon (Acipenser stellatus, Pallas, 1771) is an anadromous sturgeon species, yet little is known with regard to salt bath effect on bacterial adhesion on superficial organs of this species and its growth. This study was conducted to determine the optimal salt bath concentration on growth parameters and total bacteria count on juvenile stellate sturgeon gill and skin. A total of 200 fishes with mean initial weight 494.5 ± 2.17 g and length 62.63 ± 0.18 cm (mean ± SD) were randomly distributed into 12 concrete pools in groups of 25. Fishes exposed to acute salinity of 0, 5, 10, and 15ppt for 30 minutes. Salt bath is used 5 times for 60 days (1, 15, 30, 45 and 60). At the end of 60th day, growth indices including body weight, SGR, BWI, ADG, PER and FE revealed a significant increase at 5ppt salinity (P< 0.05) and fishes exposed to 15ppt exhibited the poorest growth. No statistical significant difference was observed between control and other treatments in total protein and albumin, also in total bacteria count in gill and skin of fishes (P>0.05) but higher levels of total protein and albumin and lower level of total bacteria observed in 5ppt treatment. The results of this study indicate that high acute salinity may compromise the growth of juvenile long nose sturgeon and suggest that, in commercial operations, salinity should be 5ppt.
Faraz Panjvini, Kourosh Sarvi Moghanlou, Raheleh Tahmasebi, Ahmad Imani,
Volume 11, Issue 2 (5-2022)
Abstract
In this study, the effects of different levels of dietary supplementation with vitamin C, astaxanthin and lecithin on ionic (K+, Na+, Ca2+ and Mg2+) and biochemical (Total protein, cholesterol and glucose) indices of ovarian fluid, also its effect on sperm motility duration in Caspian brown trout (Salmo trutta caspius) were investigated. For this purpose, nine experimental diets: C0A0L0 (0 mg kg-1 vitamin C, 0 mg kg-1 astaxanthin and 0% soybean lecithin), C300A50L0, C700A100L0, C0A50L6, C300A100L6, C700A0L6, C0A100L9, C300A0L9 and C700A50L9 were formulated and broodstocks (2.51±0.05 kg) were fed for four months. After maturation and stripping, ovarian fluid was separated for ionic and biochemical indices. To evaluate sperm motility, 1 μl of milt was placed under a microscope with fresh water (as a control treatment) or ovarian fluid of experimental fishes. Sperm motility was measured with a chronometer. Results showed that the highest amounts of Na+, K+, Ca2+ and Mg2+ ions were obtained in ovarian fluid of C300A100L6, C300A100L6, C0A100L9 and C300A100L6, respectively, which were significantly different from C700A50L9 (p<0.05). Also, the highest levels of protein, cholesterol and glucose were observed in C700A50L9, C0A50L6 and C0A100L9 treatments, which were significantly different from C0A0L0 treatment (p<0.05). Lowest duration of sperm motility was obtained in fresh water (43.96±2.25 seconds) which was significantly different from other treatments (p<0.05); however, the highest sperm motility was observed in C300A100L6 and C0A100L9 treatments (80.76±2.03 and 80.7±1.76 seconds, respectively).
Amirhossein Valipour, Abdolmohammad Abedian Kenari, Mehdi Tabarsa,
Volume 11, Issue 3 (8-2022)
Abstract
This experiment evaluated the effect of soluble polysaccharides in Spirulina platensis microalgae on growth performance, body composition and immune response of rainbow trout (Oncorhynchus mykiss). In this regard, 180 rainbow trout (17.22 ± 0.5g) were selected and distributed in five experimental treatments (with three replications). Treatments included different levels of polysaccharide in dosage of 0 (control), 500, 1000, 2000 and 3000 mg / kg of feed. According to the results, in growth factors (final weight, body weight gain, specific growth factor, protein efficiency, feed conversion ratio and condition factor), no significant difference was observed. The highest and the lowest amount of carcass proteins were observed in the diet containing 500 mg polysaccharide and control, which showed a significant difference. The amount of fatty acids of the muscle of the fish body did not show any significant difference among the treatments. The highest and lowest levels of lysozyme activity were observed in treatments of 2,000 mg polysaccharide and control and the highest and lowest levels of complement activity were observed in treatments containing 3000 mg polysaccharide and control respectively (P <0.05). In general, the use of polysaccharide extracted from micro-algae did not significantly improve rainbow trout growth, but a slight improvement in growth and body composition (protein) in 500 mg polysaccharide per kg of diet was observed. In terms of safety indicators, treatments of 2,000 and 3,000 mg of polysaccharides per kg of diet had a good performance and could be used whenever needed.
Takavar Mohammadian, Sakineh Mashjoor, Saeideh Lotfi, Hassan Bakhshi, Reza Ghanei-Motlagh,
Volume 11, Issue 3 (8-2022)
Abstract
Today, due to the confirmation of the existence of polyphenolic compounds with antioxidant properties in pomegranate peel, the study of its application potential in food health and fishery products has been the focus of researchers. In the present study, the effects of oral administration of ethanolic extract of pomegranate peel (Punica granatum L.) (Dose: 600 mg/kg) on functional changes of antioxidant system and biochemical parameters of blood serum of common carp (Cyprinus carpio) during a 45-day exposure against stocking density stress was monitored. In this regard, fish were randomly divided into 6 groups (3 treatment groups and 3 control groups with different levels of stocking density (3, 5, and 10 kg / m3) and three replications. At the end of the exposure period, fish bloodletting and serum preparation were performed. The results of this study did not show a significant increase in biochemical parameters (phosphorus, chlorine, magnesium, calcium, and triglycerides) as well as the activity level of some enzymes and antioxidant compounds such as SOD and MDA in fish serum compared to the control group. However, for stress indicators such as glucose and cholesterol and antioxidant activity such as CAT and GSH, production level has been significant. According to the findings, oral administration of pomegranate peel extract dietary supplement is recommended for consumption in dense aquaculture centers of common carp fish.
Zeynab Sedaghat, Hossein Adineh, Mohammad Harsij, Mohammad Farhangi,
Volume 11, Issue 3 (8-2022)
Abstract
Biofloc technology is considered as a culture system for fish production reduced environmental impacts. In the present study investigated the impact of zeolite nanoparticle on water quality, growth performance, digestive enzymes and immune response of common carp (Cyprinus carpio) reared under biofloc conditions. Fish fingerlings (initial weight of 7.99 ± 0.36 g) were divided into four treatments and fed four levels of zeolite nanoparticles in the following 0 (control), 50, 100 and 200 mg kg−1 diet in biofloc system (NZ1, NZ2 and NZ3) for 60 days. Carbon to nitrogen ratio (15:1) was provided using sucrose. Water quality parameters such as nitrogen compounds were measured during the test period. At the end of the experiment, the highest growth indices and the lowest feed conversion ratio were obtained in 50 mg kg−1 diet (NZ1). Intestinal protease activities in NZ1 and NZ2 treatments were significantly higher than in the other treatments, and the highest lipase and amylase activity was related to the NZ1 treatment. The 50 and 100 Zeolite diets in biofloc conditions significantly enhanced fish immune system activity. The present study suggests that dietary supplementation with 50 and 100 mg Zeolite nanoparticles in biofloc system significantly increases growth performance, digestive enzyme, and immunological response in common carp in fish culture tanks.
Abdoljabbar Irani, Naser Agh,
Volume 11, Issue 3 (8-2022)
Abstract
| A recirculating hatchery system (RHS) and a flow-through system (FTS) in terms of major macro elements (Ca, Mg, Na and k), some microelements (Fe and Cu), total bacteria and quality characteristics of Rainbow trout eggs and larvae were comparatively studied. A recirculating system (RHS) and a flow-through system (FTS) were designed for incubating the eggs and rearing the yolk-sac larvae. Fertilized eggs were distributed (5000 eggs in each tray) in four replicates and incubated under the standard conditions until yolk sac absorption. Total bacteria and macro/micro elements were measured at one-week interval. Eyed egg percentage, hatching rate, growth, and survival rate of larvae were measured. In the FTS and RHS, percentages of the eyed eggs were 79.75% and 79.01% respectively, and hatching rates were 70.31% and 63.65%, respectively. There were no significant differences amongst the values of Ca, Mg, and Na during the experimental period and between two systems. K Values in the RHS were significantly higher than in the FTS during the egg incubation period. Fe Values in the RHS were more than in the FTS, and increased during the study period in both systems. The values of total bacteria in the RHS were significantly higher than in the FTS. Despite the differences observed between the experimental systems, the designed RHS can be used for incubating the eggs and rearing the yolk-sac larvae in rainbow trout hatcheries, because of its simplicity, low water consumption, and acceptable efficiency. |
Azin Fahim, Mohammad Reza Kalbassi, Abdolmohammad Abedian Kenari, Mohammad Sadegh Sabet,
Volume 11, Issue 4 (12-2022)
Abstract
The aim of this study is to investigate the changes in fatty acid composition in Nannochloropsis oculata microalgae under physicochemical stresses (light intensity and salinity). In this regard, the growth rate, the amount of chlorophyll and carotenoid, the approximate analysis and the profile of fatty acid changes of marine microalgae N. oculata under two mutual stresses of salinity (15, 25 and 40 g/l) and light intensity (Lux 1500 and Lux 10000) which at the end of the phase Logarithms were applied are examined. The results showed that according to the application of stresses after the completion of growth, there was no significant difference in the growth rate in different treatments (P>0.05). Also, despite the fact that the highest amount of lipid was obtained under the salinity treatment of 40 g/l and the light intensity of Lux 1500, the highest amount of saturated fatty acids (SFA) was obtained under the treatment of salinity of 15 g/l and the light intensity of 10000 Lux, the highest amount of monounsaturated fatty acids (MUFA) under 25 g/l treatment and 10000 Lux light intensity and the highest amount of polyunsaturated fatty acids (PUFA) under 15 g/l treatment and 10000 Lux light intensity were obtained after 4 days of stress. Considering the effectiveness of fatty acid compounds in N. oculata microalgae, by controlling the cultivation conditions, the maximum amount of desired fatty acids can be achieved in accordance with the desired goals.
Gholamali Akbarzadeh Chomachaei, Fereshteh Saraji, Hadi Koohkan, Siyamak Behzadi, Mohammad Darvishi, Seyedeh Laili Mohebbi-Nozar,
Volume 12, Issue 1 (12-2022)
Abstract
In this study, the possible impact Asian sea bass fish (Lates calcarifer) cages culture on the population structure of phytoplankton in the coastal waters of Qeshm Island.Water sampling was done monthly for a period of six months in three stations from October 2018 to March 2019.The results showed that the mean Variations of total abundance of phytoplankton at the location of fish cages culture compared to the Reference station had a significant increase (P <0.05). At the location of cages culture, the Trophic status level was high (<5), the risk of eutrophication status (<4) and the value of trophic efficiency coefficient were high. According to the analysis of Simper test, Among the Forty-one genera identified, Noctiluca sp. with a relative abundance of % 82.37, contribution rate of 21.8% with high algal bloom at the location of cages in autumn season and then the genera Chaetoceros sp., Nitzschia sp. and Coclodinium sp. with a relative abundance of less than 10 percent in differentiating the population structure of phytoplankton have played a significant role in the dissimilarity of the population structure of phytoplankton between stations In general, in this study, the effects of fish farming activities on the population structure of phytoplankton are ineffective, but it causes the abundance of some species, available nutrients, increases the trophic level, and the probability of harmful algal blooms in the location of the cages culture.
Seyyed Morteza Hoseini, Seyed Hossein Hoseinifar, Isa Sharifpour, Melika Ghelichpour, Abbasali Aghaei Moghaddam, Mahmoud Hafezieh,
Volume 12, Issue 3 (9-2023)
Abstract
This study was conducted to investigate the effect of adding Bacillus subtilis (IS02) to the diet on survival, biochemical indices, and histological alternations of juvenile wild common carp, Cyprinus carpio, exposed to salinity stress. Juvenile common carp (about 1.1 g) were fed diets containing 0 (control), 2.5 × 108 (pro-8), and 2.5 × 109 (pro-9) cfu/g probiotic for 15 days and then transferred directly to brackish water (13 g/L) and sampled after 3 and 10 days. Diet and sampling time had no significant effect on fish survival, which was above 96% in all treatments. Body moisture and potassium were only affected by sampling time, with moisture decreasing significantly after salinity stress while potassium increased significantly. Whole body sodium in pro-8 treatment did not change significantly during salinity stress, and probiotic treatments had lower chloride levels than the control before and after salinity stress. Adding probiotic to the diet increased glutathione reductase, glutathione peroxidase activity, and reduced glutathione concentration, while decreasing malondialdehyde concentration. Probiotics caused white blood cells infiltration in the kidney tissue. No significant tissue damage was observed in the gill and kidney, compared to the control after salinity stress. This study shows that juvenile wild common carp can tolerate direct transfer to the Caspian Sea without dietary probiotic supplementation. However, probiotic stimulates the kidney immunity, enhances ionoregulation, and increase antioxidant capacity in fish, which can have beneficial effects under field conditions.
