The present study investigated the effects of dietary lactic acid (LA) supplementation on
the gro... more The present study investigated the effects of dietary lactic acid (LA) supplementation on the growth performance, intestinal digestive/antioxidant enzymes’ activities, gene expression, and bacterial communities in common carp, Cyprinus carpio. Four diets were formulated to contain 0 g/kg LA (control), at 2.5 g/kg LA (2.5LAC), 5 g/kg LA (5LAC), and 10 g/kg LA (10LAC) and offered to the fish over a period of 56 days. The results showed that dietary 5 g/kg LA supplementation improved growth performance and feed efficiency in the fish. All LA treatments exhibited significant elevations in the intestinal trypsin and chymotrypsin activities, whereas the intestinal lipase, amylase, and alkaline phosphatase activities exhibited significant elevations in the 5LAC and 10LAC treatments. All LA treatments exhibited significant elevations in the intestinal heat shock protein 70, tumor necrosis factor-alpha, interleukin-1 beta, and defensin gene expressions, and the highest expression was observed in the 5LAC treatment. Additionally, dietary LA treatment significantly increased the lysozyme expression and Lactobacillus sp. population in the intestine of the fish, and the highest values were observed in the 5LAC and 10LAC treatments. Aeromonas sp. and Vibrio sp. populations decreased in the LA treatments, and the lowest Aeromonas sp. population was observed in the 10LAC treatment. The intestinal mucin2 and mucin5 expressions, and the hepatic reduced glutathione content, significantly increased, whereas hepatic glutathione peroxidase, glutathione reductase, and malondialdehyde significantly decreased in the 5LAC and 10LAC treatments. In conclusion, dietary 5 g/kg LA is recommended for common carp feeding to improve growth rate, antioxidant capacity, and intestinal health.
The present study investigated the effects of dietary lactic acid (LA) supplementation on the gro... more The present study investigated the effects of dietary lactic acid (LA) supplementation on the growth performance, intestinal digestive/antioxidant enzymes’ activities, gene expression, and bacterial communities in common carp, Cyprinus carpio. Four diets were formulated to contain 0 g/kg LA (control), at 2.5 g/kg LA (2.5LAC), 5 g/kg LA (5LAC), and 10 g/kg LA (10LAC) and offered to the fish over a period of 56 days. The results showed that dietary 5 g/kg LA supplementation improved growth performance and feed efficiency in the fish. All LA treatments exhibited significant elevations in the intestinal trypsin and chymotrypsin activities, whereas the intestinal lipase, amylase, and alkaline phosphatase activities exhibited significant elevations in the 5LAC and 10LAC treatments. All LA treatments exhibited significant elevations in the intestinal heat shock protein 70, tumor necrosis factor-alpha, interleukin-1 beta, and defensin gene expressions, and the highest expression was observe...
Journal of Experimental Zoology Part A: Ecological and Integrative Physiology, 2021
The aim of this study was to assess the anesthetic efficacy and biochemical effects of citronella... more The aim of this study was to assess the anesthetic efficacy and biochemical effects of citronellal on rainbow trout, Oncorhynchus mykiss. The fish were exposed to 200-800 µl/L citronellal to find the anesthesia induction and recovery times. The deep anesthesia stage was reached within 117-613 s, using 800-200 µl/L citronellal, respectively, and all fish recovered within 240-420 s. To assess biochemical responses, the fish were exposed to 200, 400, 600, and 800 µl/L of citronellal and blood-sampled after deep anesthesia. The results showed that anesthesia led to significant elevations in blood erythrocytes, hematocrit, hemoglobin, mean corpuscular volume, plasma lactate, and lactate dehydrogenase; these parameters exhibited increasing trends as citronellal concentration increased. These results along with significantly higher plasma lysozyme activity, cortisol, and glucose levels in 200 µl/L treatment suggest that an increase in citronellal concentration significantly mitigates hypoxia/stress responses in the fish. Significant elevations in plasma alkaline phosphatase activity and malondialdehyde level were observed in the 200 µl/L treatment, which suggests induction of hemolysis and oxidative stress in this treatment. There was a tendency to higher ammonia levels along with the increase in citronellal concentration, which might be due to early ammonia accumulation because of lower opercular movement in the fish. Except for blood hematocrit and mean corpuscular volume, there were no significant differences between the 600 and 800 µl/L citronellal treatments. In conclusion, high concentrations of citronellal are more suitable for trout anesthesia and blood sampling than low concentrations. Based on the present study, 600-800 µl/L citronellal is recommended for trout anesthesia.
The effects of salinity and nutritional status on the growth performance as well as body composit... more The effects of salinity and nutritional status on the growth performance as well as body composition of the Indian white shrimp (Fenneropenaeus indicus) were investigated. Juveniles of shrimp (35 days old; 0.25 g mean weight) were exposed to salinities of 10, 20, 30, 40 and 50 g L-1 (experiment І). Results showed that salinity affected the growth and survival of juvenile F. indicus significantly (P<0.05). The highest weight gain, final weight and carapace length gain and lower FCR were observed at 20 g L-1 of salinity and the highest food intake, SGR and survival were determined at 30 g L-1 of salinity. A 3×3 factorial experiment containing three levels of dietary protein (35, 40 and 45%) and three levels of salinity (25, 35 and 45 g L-1) was performed for 60 days to determine the response of shrimp (mean weight of 3.21±0.12 g) to different dietary proteins under different salinity conditions (experiment П). Results revealed that growth performance was improved due to increase in...
This study was carried out to investigate the optimum stocking density for white leg shrimp (Lito... more This study was carried out to investigate the optimum stocking density for white leg shrimp (Litopenaeus vannamei) in earthen ponds in Choweibdeh shrimp site Abadan southwest Iran. Six 0.5 ha. Earthen ponds were applied to survey three stocking density of this shrimp (30, 45 and 60 indviduals/m^2) with two replicates each. 15 days old postlarvae (PL15) with mean weight of 0.021 g were reared in the experimental ponds for 60 days. Results showed no significant difference (P>0.05 ) between the tested stocking densities in terms of growth (weight gain, length increment), specific growth rate (SG ), weekly growth rate, survival rate, food conversion ratio (FCR ) and protein efficiency rate (PER). Nevertheless best results were obtained in the stocking density with 30 ind./m^2 . Yield was increased by increasing the stocking density and the highest yield was obtained in the density of 60 ind./m^2 with significant difference with two other densities. Ultimately, according to the findin...
To investigate an economical diet for white pacific prawn (Litopenaeus vannamei) rearing coastal ... more To investigate an economical diet for white pacific prawn (Litopenaeus vannamei) rearing coastal zones of south Iran, 9 experimental diets were prepared considering three protein (37%, 37%, 40% CP) and three digestible energy (262, 312, 362 kcal. 100g^-1 DE) levels, using herbal protein source (soybean meal) as main protein source for the diets. 27 polyethylene round tanks (300 L volume) provided with aerated flow-through water system, stocked with …juvenile shrimps (9.16 ± 0.05 g mean weight) were applied to evaluate the growth performance of the shrimps and feed efficiency parameters of the diets for 8 weeks rearing period in an in-door experimental system. Results showed the diets were significantly different (P≤0.05)in the terms of growth performance and diet efficiency the shrimp, while the best obtaining observed in diet 1 (34% CP and 262 kcal. 100g^-1 DE). Average of weight gain was ranged from 4.58 ± 0.52 g in Diet 9 up to 6.88 ± 0.81 g in diet one, SGR was from 0.73 ± 0.06 ...
The present study was carried out to evaluate the possibility of rearing the orange-spotted group... more The present study was carried out to evaluate the possibility of rearing the orange-spotted grouper (E. coioides) juvenile to marketable size in buoyant cages in Khuzestan province coast waters. Juvenile fishes for the study prepared from Bandar-e-Imam Marine Fish Station and reared them in 5-ton fiber glass tank for one year period using common pellet feed and trash fish to reach 50 g mean weight. Young fishes were stocked in 6 rectangular cages (3×3×3 m) to assess their growth performance with two test feeds i.e. pellet feed and trash fish (3 cages for each treatment) with the density of 30 fish /m^3 (810 fish/cage) for 143 days rearing period (started on July). Better growth with significant difference (p0.05). Results also showed that the FCR for the trash fish was acceptable, and hence it is recommended to consider the trash fish price and its labour cost befor using it as the main diet in cage culture activity
A 30-day research was conducted to evaluate the effects of different feeding rate (2, 4, 6, 8 and... more A 30-day research was conducted to evaluate the effects of different feeding rate (2, 4, 6, 8 and 10% of wet body weight/day) and also fresh food (20% of wet body weight/day) on growth performance and feed utilization of Acanthopagrus latus fry in nursery phase. Fish that fed with fresh food had the lowest survival rate and feed efficiency in comparison with other treatments. Growth performance including final weight and specific growth rate (SGR) significantly increased with increasing feeding rate (p< 0.05). The relationship between SGR (% per day) and ration level (% per day) was an asymptotic curve described as SGR=0.3196X+0.7319. There were not significant differences in hepatosomatic, viscerosomatic and condition factor indices among different treatments. Based on the above results, it may be concluded that a ration size of 8% of body weight per day is optimal for good growth and feed conversion efficiency of juvenile A. latus in nursery phase.
The presnt study has been carried out to evaluate the Nannochloropsis oculata culture performance... more The presnt study has been carried out to evaluate the Nannochloropsis oculata culture performance in 100L columnar plastic bags under two chemical media (TMRL and CONWAY) and 3 light regimes in the controlled conditions. Algae used for the experiment has been provided through culture of primitive stock and by transferring it to 2 L glassy erlenmeyer and 15 L plastic containers (as intermediate stage) using CONWAY media respectively. Daily evaluation of algae concentration was carried out during the 18 days culture period. At the end of the study produced algae has been sedimented to be used for evaluation of the dried matter and algae biomass. Results of the study showed that the concentration of the algae culture was 22±3.34×106 cells. ml^-1, at 8th day, and reached the concentration of 26.58±4.02×106 cells. ml^-1 at the final day of the culture course. Although the results revealed the possibility of achievement of acceptable concentration for the N.oculta by the method adopted in...
Abstract The aim of the present study was to investigate the effects of dietary tryptophan (Trp) ... more Abstract The aim of the present study was to investigate the effects of dietary tryptophan (Trp) supplementation on growth performance and stress responses of rainbow trout (Oncorhynchus mykiss) at low (LD) and high (HD) stocking density. For this, three diets were formulated by supplementing 0% (control), 0.5% (T0.5), and 1% (T1) Trp corresponding to 0.77, 1.85 and 3.14 g Trp per 100 g protein. In the LD treatment, the fish were initially stocked at 15 kg/m3; whereas, in the HD treatment, the fish were initially stocked at 25 kg/m3. The fish were reared under these densities and with the aforementioned diets for 70 days. After the feeding trial, the fish were sampled to determine carcass proximate composition, and blood hematological and biochemical parameters. The results showed that T0.5 had higher growth performance compared to the other treatments under the LD condition; however, there was no significant difference among the treatments under the HD condition. The increase in the fish stocking density significantly increased FCR, but the Trp-treated treatments had significantly lower FCR compared to the control treatment. Increase in the fish stocking density significantly increased carcass moisture, but decreased the carcass protein and lipid levels. The T0.5 treatment had significantly higher carcass lipid levels compared to the other treatments at the LD condition. The T0.5 treatment had significantly lower cortisol and glucose, and higher T3 levels compared to the other treatments under the LD condition; however, there was no significant difference among the treatments under the HD condition. Blood RBC and hemoglobin values significantly increased in the fish fed with 0.5% Trp supplementation; moreover, the increase in the fish stocking density significantly increased these parameters. The T0.5 treatment had significantly higher blood hematocrit levels compared to the other treatments at the LD condition. In conclusion, dietary Trp supplementation at 0.5% level is beneficial to augment growth performance in rainbow trout, when the fish initial biomass is 15 kg/m3. The mechanism of growth promotion effects of 0.5% Trp was found to be related to stress suppression. Further studies would provide data about the potential effects of Trp on rainbow trout under higher stocking densities.
Sobaity seabream is one of the candid species for mariculture in the Persian Gulf and Oman Sea, i... more Sobaity seabream is one of the candid species for mariculture in the Persian Gulf and Oman Sea, in this regard; several studies have been done to find optimum feed formulation for this species. The results of these researches revealed that feed formulation for this species should have at least ca. 48% crude protein, 15% crude lipid, 15% carbohydrates, and 20 KJ/g gross energy. In addition, the optimum essential amino acid profile for this species (expressed as g 16 g N), should be approximately arginine 5.3, lysine 6.0, threonine 5.2, histidine 2.5, isoleucine 4.6, leucine 5.4, methionine + cysteine 4.0 (in a diet containing 0.6 cysteine), phenylalanine + tyrosine 5.6 (in a diet containing 1.9 tyrosine), tryptophan 1.0 and valine 4.6. Moreover, the optimum dietary n-3 long chain polyunsaturated fatty acids and soybean lecithin are recommended to be 0.8% and 6%, respectively. The maximum replacement of fish meal with soy protein is recommended to be 27.3%. On the other hand, this rec...
A 30-day research was conducted to evaluate the effects of different feeding rate (2, 4, 6, 8 and... more A 30-day research was conducted to evaluate the effects of different feeding rate (2, 4, 6, 8 and 10% of wet body weight/day) and also fresh food (20% of wet body weight/day) on growth performance and feed utilization of Acanthopagrus latus fry in nursery phase. Fish that fed with fresh food had the lowest survival rate and feed efficiency in comparison with other treatments. Growth performance including final weight and specific growth rate (SGR) significantly increased with increasing feeding rate (p< 0.05). The relationship between SGR (% per day) and ration level (% per day) was an asymptotic curve described as SGR=0.3196X+0.7319. There were not significant differences in hepatosomatic, viscerosomatic and condition factor indices among different treatments. Based on the above results, it may be concluded that a ration size of 8% of body weight per day is optimal for good growth and feed conversion efficiency of juvenile A. latus in nursery phase.
An eight-week research was carried out to examine the influence of fasting (FA) and refeeding (RF... more An eight-week research was carried out to examine the influence of fasting (FA) and refeeding (RF) episodes on the compensatory growth responses (CGR) in sobaity (Sparidentex hasta, 10 g) and yellowfin seabreams (Acanthopagrus latus, 4.3 g) juveniles. Fish were fed with a commercial feed (contained 500 g kg−1 crude protein and 150 g kg−1 crude lipid) as following regimes: control (C, fish were fed three times every day), T1 (two weeks of feeding, one week of FA, and five weeks of RF), T2 (one week of feeding, two weeks of FA and five weeks of RF) and T3 (three weeks of FA and five weeks of RF). Two hundred and forty S. hasta juveniles were stocked into twelve 300-L tanks (20 fish tank−1), and 360 A. latus juveniles were allocated into other 12 tanks (30 fish tank−1). Each treatment was carried out in triplicates for each species, and each tank held only one of the species. The experiment was carried out for both species simultaneously. The weight and length of fish from the four gro...
An eight-week study was conducted on silvery-black porgy (Sparidentex hasta) juveniles to evaluat... more An eight-week study was conducted on silvery-black porgy (Sparidentex hasta) juveniles to evaluate four isoproteic, isolipidic and isoenergetic different diets (50% crude protein, 20% crude lipids, 18.5 MJ kg −1) containing graded levels of soybean lecithin (SBL) (0, 30, 60 and 90 g kg −1 diet) at the expense of fish oil (FO). Fish fed the 60 g SBL kg −1 diet had significantly higher weight gain (32.4%) and feed intake (8.8 g fish −1) than the control group (SBL 0) (P < 0.05). The fillet fatty acid (FA) profiles were correlated with the FA profile of the experimental diets. Fish fed with SBL-supplemented diets had higher fillet phosphatidylcholine levels than the control group (P < 0.05). Plasma total immunoglobulin was higher in fish fed 60 and 90 g SBL kg −1 diets than in the other groups (P < 0.05). Total protease activity was higher in fish fed the 90 g SLB kg −1 diet than other treatments (P < 0.05). Results indicated that substitution of dietary FO with SBL diet up to 67% (60 g SLB kg −1 diet) improved somatic growth performance and profoundly affected the fillet fatty acid profile in silvery-black porgy juveniles.
The present study investigated the effects of dietary lactic acid (LA) supplementation on
the gro... more The present study investigated the effects of dietary lactic acid (LA) supplementation on the growth performance, intestinal digestive/antioxidant enzymes’ activities, gene expression, and bacterial communities in common carp, Cyprinus carpio. Four diets were formulated to contain 0 g/kg LA (control), at 2.5 g/kg LA (2.5LAC), 5 g/kg LA (5LAC), and 10 g/kg LA (10LAC) and offered to the fish over a period of 56 days. The results showed that dietary 5 g/kg LA supplementation improved growth performance and feed efficiency in the fish. All LA treatments exhibited significant elevations in the intestinal trypsin and chymotrypsin activities, whereas the intestinal lipase, amylase, and alkaline phosphatase activities exhibited significant elevations in the 5LAC and 10LAC treatments. All LA treatments exhibited significant elevations in the intestinal heat shock protein 70, tumor necrosis factor-alpha, interleukin-1 beta, and defensin gene expressions, and the highest expression was observed in the 5LAC treatment. Additionally, dietary LA treatment significantly increased the lysozyme expression and Lactobacillus sp. population in the intestine of the fish, and the highest values were observed in the 5LAC and 10LAC treatments. Aeromonas sp. and Vibrio sp. populations decreased in the LA treatments, and the lowest Aeromonas sp. population was observed in the 10LAC treatment. The intestinal mucin2 and mucin5 expressions, and the hepatic reduced glutathione content, significantly increased, whereas hepatic glutathione peroxidase, glutathione reductase, and malondialdehyde significantly decreased in the 5LAC and 10LAC treatments. In conclusion, dietary 5 g/kg LA is recommended for common carp feeding to improve growth rate, antioxidant capacity, and intestinal health.
The present study investigated the effects of dietary lactic acid (LA) supplementation on the gro... more The present study investigated the effects of dietary lactic acid (LA) supplementation on the growth performance, intestinal digestive/antioxidant enzymes’ activities, gene expression, and bacterial communities in common carp, Cyprinus carpio. Four diets were formulated to contain 0 g/kg LA (control), at 2.5 g/kg LA (2.5LAC), 5 g/kg LA (5LAC), and 10 g/kg LA (10LAC) and offered to the fish over a period of 56 days. The results showed that dietary 5 g/kg LA supplementation improved growth performance and feed efficiency in the fish. All LA treatments exhibited significant elevations in the intestinal trypsin and chymotrypsin activities, whereas the intestinal lipase, amylase, and alkaline phosphatase activities exhibited significant elevations in the 5LAC and 10LAC treatments. All LA treatments exhibited significant elevations in the intestinal heat shock protein 70, tumor necrosis factor-alpha, interleukin-1 beta, and defensin gene expressions, and the highest expression was observe...
Journal of Experimental Zoology Part A: Ecological and Integrative Physiology, 2021
The aim of this study was to assess the anesthetic efficacy and biochemical effects of citronella... more The aim of this study was to assess the anesthetic efficacy and biochemical effects of citronellal on rainbow trout, Oncorhynchus mykiss. The fish were exposed to 200-800 µl/L citronellal to find the anesthesia induction and recovery times. The deep anesthesia stage was reached within 117-613 s, using 800-200 µl/L citronellal, respectively, and all fish recovered within 240-420 s. To assess biochemical responses, the fish were exposed to 200, 400, 600, and 800 µl/L of citronellal and blood-sampled after deep anesthesia. The results showed that anesthesia led to significant elevations in blood erythrocytes, hematocrit, hemoglobin, mean corpuscular volume, plasma lactate, and lactate dehydrogenase; these parameters exhibited increasing trends as citronellal concentration increased. These results along with significantly higher plasma lysozyme activity, cortisol, and glucose levels in 200 µl/L treatment suggest that an increase in citronellal concentration significantly mitigates hypoxia/stress responses in the fish. Significant elevations in plasma alkaline phosphatase activity and malondialdehyde level were observed in the 200 µl/L treatment, which suggests induction of hemolysis and oxidative stress in this treatment. There was a tendency to higher ammonia levels along with the increase in citronellal concentration, which might be due to early ammonia accumulation because of lower opercular movement in the fish. Except for blood hematocrit and mean corpuscular volume, there were no significant differences between the 600 and 800 µl/L citronellal treatments. In conclusion, high concentrations of citronellal are more suitable for trout anesthesia and blood sampling than low concentrations. Based on the present study, 600-800 µl/L citronellal is recommended for trout anesthesia.
The effects of salinity and nutritional status on the growth performance as well as body composit... more The effects of salinity and nutritional status on the growth performance as well as body composition of the Indian white shrimp (Fenneropenaeus indicus) were investigated. Juveniles of shrimp (35 days old; 0.25 g mean weight) were exposed to salinities of 10, 20, 30, 40 and 50 g L-1 (experiment І). Results showed that salinity affected the growth and survival of juvenile F. indicus significantly (P<0.05). The highest weight gain, final weight and carapace length gain and lower FCR were observed at 20 g L-1 of salinity and the highest food intake, SGR and survival were determined at 30 g L-1 of salinity. A 3×3 factorial experiment containing three levels of dietary protein (35, 40 and 45%) and three levels of salinity (25, 35 and 45 g L-1) was performed for 60 days to determine the response of shrimp (mean weight of 3.21±0.12 g) to different dietary proteins under different salinity conditions (experiment П). Results revealed that growth performance was improved due to increase in...
This study was carried out to investigate the optimum stocking density for white leg shrimp (Lito... more This study was carried out to investigate the optimum stocking density for white leg shrimp (Litopenaeus vannamei) in earthen ponds in Choweibdeh shrimp site Abadan southwest Iran. Six 0.5 ha. Earthen ponds were applied to survey three stocking density of this shrimp (30, 45 and 60 indviduals/m^2) with two replicates each. 15 days old postlarvae (PL15) with mean weight of 0.021 g were reared in the experimental ponds for 60 days. Results showed no significant difference (P>0.05 ) between the tested stocking densities in terms of growth (weight gain, length increment), specific growth rate (SG ), weekly growth rate, survival rate, food conversion ratio (FCR ) and protein efficiency rate (PER). Nevertheless best results were obtained in the stocking density with 30 ind./m^2 . Yield was increased by increasing the stocking density and the highest yield was obtained in the density of 60 ind./m^2 with significant difference with two other densities. Ultimately, according to the findin...
To investigate an economical diet for white pacific prawn (Litopenaeus vannamei) rearing coastal ... more To investigate an economical diet for white pacific prawn (Litopenaeus vannamei) rearing coastal zones of south Iran, 9 experimental diets were prepared considering three protein (37%, 37%, 40% CP) and three digestible energy (262, 312, 362 kcal. 100g^-1 DE) levels, using herbal protein source (soybean meal) as main protein source for the diets. 27 polyethylene round tanks (300 L volume) provided with aerated flow-through water system, stocked with …juvenile shrimps (9.16 ± 0.05 g mean weight) were applied to evaluate the growth performance of the shrimps and feed efficiency parameters of the diets for 8 weeks rearing period in an in-door experimental system. Results showed the diets were significantly different (P≤0.05)in the terms of growth performance and diet efficiency the shrimp, while the best obtaining observed in diet 1 (34% CP and 262 kcal. 100g^-1 DE). Average of weight gain was ranged from 4.58 ± 0.52 g in Diet 9 up to 6.88 ± 0.81 g in diet one, SGR was from 0.73 ± 0.06 ...
The present study was carried out to evaluate the possibility of rearing the orange-spotted group... more The present study was carried out to evaluate the possibility of rearing the orange-spotted grouper (E. coioides) juvenile to marketable size in buoyant cages in Khuzestan province coast waters. Juvenile fishes for the study prepared from Bandar-e-Imam Marine Fish Station and reared them in 5-ton fiber glass tank for one year period using common pellet feed and trash fish to reach 50 g mean weight. Young fishes were stocked in 6 rectangular cages (3×3×3 m) to assess their growth performance with two test feeds i.e. pellet feed and trash fish (3 cages for each treatment) with the density of 30 fish /m^3 (810 fish/cage) for 143 days rearing period (started on July). Better growth with significant difference (p0.05). Results also showed that the FCR for the trash fish was acceptable, and hence it is recommended to consider the trash fish price and its labour cost befor using it as the main diet in cage culture activity
A 30-day research was conducted to evaluate the effects of different feeding rate (2, 4, 6, 8 and... more A 30-day research was conducted to evaluate the effects of different feeding rate (2, 4, 6, 8 and 10% of wet body weight/day) and also fresh food (20% of wet body weight/day) on growth performance and feed utilization of Acanthopagrus latus fry in nursery phase. Fish that fed with fresh food had the lowest survival rate and feed efficiency in comparison with other treatments. Growth performance including final weight and specific growth rate (SGR) significantly increased with increasing feeding rate (p< 0.05). The relationship between SGR (% per day) and ration level (% per day) was an asymptotic curve described as SGR=0.3196X+0.7319. There were not significant differences in hepatosomatic, viscerosomatic and condition factor indices among different treatments. Based on the above results, it may be concluded that a ration size of 8% of body weight per day is optimal for good growth and feed conversion efficiency of juvenile A. latus in nursery phase.
The presnt study has been carried out to evaluate the Nannochloropsis oculata culture performance... more The presnt study has been carried out to evaluate the Nannochloropsis oculata culture performance in 100L columnar plastic bags under two chemical media (TMRL and CONWAY) and 3 light regimes in the controlled conditions. Algae used for the experiment has been provided through culture of primitive stock and by transferring it to 2 L glassy erlenmeyer and 15 L plastic containers (as intermediate stage) using CONWAY media respectively. Daily evaluation of algae concentration was carried out during the 18 days culture period. At the end of the study produced algae has been sedimented to be used for evaluation of the dried matter and algae biomass. Results of the study showed that the concentration of the algae culture was 22±3.34×106 cells. ml^-1, at 8th day, and reached the concentration of 26.58±4.02×106 cells. ml^-1 at the final day of the culture course. Although the results revealed the possibility of achievement of acceptable concentration for the N.oculta by the method adopted in...
Abstract The aim of the present study was to investigate the effects of dietary tryptophan (Trp) ... more Abstract The aim of the present study was to investigate the effects of dietary tryptophan (Trp) supplementation on growth performance and stress responses of rainbow trout (Oncorhynchus mykiss) at low (LD) and high (HD) stocking density. For this, three diets were formulated by supplementing 0% (control), 0.5% (T0.5), and 1% (T1) Trp corresponding to 0.77, 1.85 and 3.14 g Trp per 100 g protein. In the LD treatment, the fish were initially stocked at 15 kg/m3; whereas, in the HD treatment, the fish were initially stocked at 25 kg/m3. The fish were reared under these densities and with the aforementioned diets for 70 days. After the feeding trial, the fish were sampled to determine carcass proximate composition, and blood hematological and biochemical parameters. The results showed that T0.5 had higher growth performance compared to the other treatments under the LD condition; however, there was no significant difference among the treatments under the HD condition. The increase in the fish stocking density significantly increased FCR, but the Trp-treated treatments had significantly lower FCR compared to the control treatment. Increase in the fish stocking density significantly increased carcass moisture, but decreased the carcass protein and lipid levels. The T0.5 treatment had significantly higher carcass lipid levels compared to the other treatments at the LD condition. The T0.5 treatment had significantly lower cortisol and glucose, and higher T3 levels compared to the other treatments under the LD condition; however, there was no significant difference among the treatments under the HD condition. Blood RBC and hemoglobin values significantly increased in the fish fed with 0.5% Trp supplementation; moreover, the increase in the fish stocking density significantly increased these parameters. The T0.5 treatment had significantly higher blood hematocrit levels compared to the other treatments at the LD condition. In conclusion, dietary Trp supplementation at 0.5% level is beneficial to augment growth performance in rainbow trout, when the fish initial biomass is 15 kg/m3. The mechanism of growth promotion effects of 0.5% Trp was found to be related to stress suppression. Further studies would provide data about the potential effects of Trp on rainbow trout under higher stocking densities.
Sobaity seabream is one of the candid species for mariculture in the Persian Gulf and Oman Sea, i... more Sobaity seabream is one of the candid species for mariculture in the Persian Gulf and Oman Sea, in this regard; several studies have been done to find optimum feed formulation for this species. The results of these researches revealed that feed formulation for this species should have at least ca. 48% crude protein, 15% crude lipid, 15% carbohydrates, and 20 KJ/g gross energy. In addition, the optimum essential amino acid profile for this species (expressed as g 16 g N), should be approximately arginine 5.3, lysine 6.0, threonine 5.2, histidine 2.5, isoleucine 4.6, leucine 5.4, methionine + cysteine 4.0 (in a diet containing 0.6 cysteine), phenylalanine + tyrosine 5.6 (in a diet containing 1.9 tyrosine), tryptophan 1.0 and valine 4.6. Moreover, the optimum dietary n-3 long chain polyunsaturated fatty acids and soybean lecithin are recommended to be 0.8% and 6%, respectively. The maximum replacement of fish meal with soy protein is recommended to be 27.3%. On the other hand, this rec...
A 30-day research was conducted to evaluate the effects of different feeding rate (2, 4, 6, 8 and... more A 30-day research was conducted to evaluate the effects of different feeding rate (2, 4, 6, 8 and 10% of wet body weight/day) and also fresh food (20% of wet body weight/day) on growth performance and feed utilization of Acanthopagrus latus fry in nursery phase. Fish that fed with fresh food had the lowest survival rate and feed efficiency in comparison with other treatments. Growth performance including final weight and specific growth rate (SGR) significantly increased with increasing feeding rate (p< 0.05). The relationship between SGR (% per day) and ration level (% per day) was an asymptotic curve described as SGR=0.3196X+0.7319. There were not significant differences in hepatosomatic, viscerosomatic and condition factor indices among different treatments. Based on the above results, it may be concluded that a ration size of 8% of body weight per day is optimal for good growth and feed conversion efficiency of juvenile A. latus in nursery phase.
An eight-week research was carried out to examine the influence of fasting (FA) and refeeding (RF... more An eight-week research was carried out to examine the influence of fasting (FA) and refeeding (RF) episodes on the compensatory growth responses (CGR) in sobaity (Sparidentex hasta, 10 g) and yellowfin seabreams (Acanthopagrus latus, 4.3 g) juveniles. Fish were fed with a commercial feed (contained 500 g kg−1 crude protein and 150 g kg−1 crude lipid) as following regimes: control (C, fish were fed three times every day), T1 (two weeks of feeding, one week of FA, and five weeks of RF), T2 (one week of feeding, two weeks of FA and five weeks of RF) and T3 (three weeks of FA and five weeks of RF). Two hundred and forty S. hasta juveniles were stocked into twelve 300-L tanks (20 fish tank−1), and 360 A. latus juveniles were allocated into other 12 tanks (30 fish tank−1). Each treatment was carried out in triplicates for each species, and each tank held only one of the species. The experiment was carried out for both species simultaneously. The weight and length of fish from the four gro...
An eight-week study was conducted on silvery-black porgy (Sparidentex hasta) juveniles to evaluat... more An eight-week study was conducted on silvery-black porgy (Sparidentex hasta) juveniles to evaluate four isoproteic, isolipidic and isoenergetic different diets (50% crude protein, 20% crude lipids, 18.5 MJ kg −1) containing graded levels of soybean lecithin (SBL) (0, 30, 60 and 90 g kg −1 diet) at the expense of fish oil (FO). Fish fed the 60 g SBL kg −1 diet had significantly higher weight gain (32.4%) and feed intake (8.8 g fish −1) than the control group (SBL 0) (P < 0.05). The fillet fatty acid (FA) profiles were correlated with the FA profile of the experimental diets. Fish fed with SBL-supplemented diets had higher fillet phosphatidylcholine levels than the control group (P < 0.05). Plasma total immunoglobulin was higher in fish fed 60 and 90 g SBL kg −1 diets than in the other groups (P < 0.05). Total protease activity was higher in fish fed the 90 g SLB kg −1 diet than other treatments (P < 0.05). Results indicated that substitution of dietary FO with SBL diet up to 67% (60 g SLB kg −1 diet) improved somatic growth performance and profoundly affected the fillet fatty acid profile in silvery-black porgy juveniles.
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Papers by Esmaeil Pagheh
the growth performance, intestinal digestive/antioxidant enzymes’ activities, gene expression, and
bacterial communities in common carp, Cyprinus carpio. Four diets were formulated to contain 0 g/kg
LA (control), at 2.5 g/kg LA (2.5LAC), 5 g/kg LA (5LAC), and 10 g/kg LA (10LAC) and offered to the
fish over a period of 56 days. The results showed that dietary 5 g/kg LA supplementation improved
growth performance and feed efficiency in the fish. All LA treatments exhibited significant elevations
in the intestinal trypsin and chymotrypsin activities, whereas the intestinal lipase, amylase, and
alkaline phosphatase activities exhibited significant elevations in the 5LAC and 10LAC treatments.
All LA treatments exhibited significant elevations in the intestinal heat shock protein 70, tumor
necrosis factor-alpha, interleukin-1 beta, and defensin gene expressions, and the highest expression
was observed in the 5LAC treatment. Additionally, dietary LA treatment significantly increased the
lysozyme expression and Lactobacillus sp. population in the intestine of the fish, and the highest
values were observed in the 5LAC and 10LAC treatments. Aeromonas sp. and Vibrio sp. populations
decreased in the LA treatments, and the lowest Aeromonas sp. population was observed in the
10LAC treatment. The intestinal mucin2 and mucin5 expressions, and the hepatic reduced glutathione
content, significantly increased, whereas hepatic glutathione peroxidase, glutathione reductase, and
malondialdehyde significantly decreased in the 5LAC and 10LAC treatments. In conclusion, dietary
5 g/kg LA is recommended for common carp feeding to improve growth rate, antioxidant capacity,
and intestinal health.
the growth performance, intestinal digestive/antioxidant enzymes’ activities, gene expression, and
bacterial communities in common carp, Cyprinus carpio. Four diets were formulated to contain 0 g/kg
LA (control), at 2.5 g/kg LA (2.5LAC), 5 g/kg LA (5LAC), and 10 g/kg LA (10LAC) and offered to the
fish over a period of 56 days. The results showed that dietary 5 g/kg LA supplementation improved
growth performance and feed efficiency in the fish. All LA treatments exhibited significant elevations
in the intestinal trypsin and chymotrypsin activities, whereas the intestinal lipase, amylase, and
alkaline phosphatase activities exhibited significant elevations in the 5LAC and 10LAC treatments.
All LA treatments exhibited significant elevations in the intestinal heat shock protein 70, tumor
necrosis factor-alpha, interleukin-1 beta, and defensin gene expressions, and the highest expression
was observed in the 5LAC treatment. Additionally, dietary LA treatment significantly increased the
lysozyme expression and Lactobacillus sp. population in the intestine of the fish, and the highest
values were observed in the 5LAC and 10LAC treatments. Aeromonas sp. and Vibrio sp. populations
decreased in the LA treatments, and the lowest Aeromonas sp. population was observed in the
10LAC treatment. The intestinal mucin2 and mucin5 expressions, and the hepatic reduced glutathione
content, significantly increased, whereas hepatic glutathione peroxidase, glutathione reductase, and
malondialdehyde significantly decreased in the 5LAC and 10LAC treatments. In conclusion, dietary
5 g/kg LA is recommended for common carp feeding to improve growth rate, antioxidant capacity,
and intestinal health.