جستجوی مقالات مرتبط با کلیدواژه « میگوی وانامی » در نشریات گروه « شیلات »

Today, the continuous release of environmental pollutants into aquatic ecosystems has made these environments extremely vulnerable and turned them into a storage sites for these toxic substances, so it is necessary to investigate the effects of these pollutants on aquatic life. The present study was conducted with the aim of determining the toxicity of silver nitrate and observing the behavioral changes of Litopenaeus vannamei during its exposure. To determine the toxicity, the standard method of OECD was used. At first, the viability and survival of Litopenaeus vannamei were checked after two weeks of acclimatization to laboratory conditions, then by conducting preliminary tests, the actual lethality values ​​of silver nitrate were obtained. In order to determine the median lethal concentration, shrimps were exposed to concentrations of  0.025, 0.05, 0.1, 0.2, 0.4 and 0.8 mg/L of silver nitrate for 96 h and their mortality were recorded daily every 24 h. The LC50, LOEC, NOEC and MATC were calculated based on shrimp mortality. During the viability and survival test, no mortality were observed up to 96 hours, and the survival rate of shrimps was 100%. The value of LC50, NOEC, LOEC and MATC were determined as 0.084, 0.02, 0.025 and 0.0084 mg/liter, respectively. In different concentrations of silver nitrate, shrimps showed behaviors such as abnormal swimming, fast movements of swimming legs, coming to the surface of the water, twisting the body around itself and eventually losing balance.

In order to investigate the resistance of shrimp against white spot disease by Gracilaria corticata algae, 300 Vannamei shrimp in two groups were fed with and without algae extract for 14 days. At the end of the experiment, half of the shrimp of each group were exposed to the white spot virus. After the challenge, during days 0, 3, 9, 18 and 25, the survival rate and immune factors of shrimp were examined. According to the results, survival rate of shrimp fed with algae extract was higher than the shrimp were fed by commercial pellet without the algae extract (positive control) significantly (P < 0.05). Immune system enhancement from the first to twenty fifth day and the highest levels of THC, TPP, SOD, POD and PO were observed in group Algae on twenty fifth day of the experiment. This condition was also observed in group AV, but less than group A with a significant difference (P <0.05). Considering the function of algae in stimulating the immune system, it seems that during the culture period, algae supplementation in the diet can be used as a proposed strategy to control white spot disease.

In order to evaluate the dietary effects of housefly larvae (Musca domestica) as an alternative to Perinereis nuntia, on fecundity rate and larval stages development of Pacific white leg shrimp Litopenaeus vannamei, 30 pairs of L. vannamei shrimp were stocked in 3 fiberglass tanks of 5 tones containing filtered seawater under identical conditions. The brooders were fed with 3 diets including conventional diets of hatchery (P. nuntia, squid, oysters and food pellets), along with 5% of housefly larvae as a supplement (Diet A), conventional diets of hatchery along with 10% of housefly larvae as an alternative to P. nuntia (Diet B) and conventional diets of hatchery as a control (Diet C). The experiment results showed that diet A presented significant differences in promoting fecundity rates of shrimp broodstocks with the other treatments (p<0.05). The number of hatching eggs (hatching) in the treatments did not show any significant difference (p>0.05). The larval development stages of hatched eggs produced with different treatments showed that a greater percentage of larvae from broodstocks fed with diet A have developed faster to the next stage than the other two treatments, which has shown a significant difference (p<0.05), especially in post-larvae stages. However, the use of housefly larvae diet as a supplement to conventional diets of hatchery can increase the fecundity rates of shrimp broodstocks and result in faster larval development; but as an alternative to the polychaete worm (P. nuntia) in conventional diets of the hatchery, have no effect on shrimp broodstock hatcheries.

In the present study, the effect of alcoholic essential oil of Mentha piperita at concentrations of 0, 0.5 and 1% and at 4, -3 and -10 °C on the shelf-life of Litopenaeus vannamei during 15 days of storage, using by response surface method was analyzes. Essential oil analysis using GC-MS showed the menthol as the most abundant compound in essential oil. About total viable count (TVC), the total volatile nitrogen bases (TVB-N), peroxide value (PV), thiobarbituric acid (TBA) and free fatty acid (FFA) concentration of essential oil, with high level of F-value compared to time and temperature, was the most important factor affecting the shelf life of shrimp (p < 0.05). Shrimp kept at -10°C on the 7 and 15th days of storage at 0.5 and 1% concentrations, respectively, were within the allowable range for human consumption. Based on the results, TVC and then TVB-N were the most important factors in determining the shelf life of shrimp. The regression coefficient (R2, R2-adj) showed that, the regression model was able to describe the relationships between the various variables of time, temperature and essential oil concentration and the dependent variables and the obtained models predicted near-realistic values that could be they used it as a way to reduce the cost of testing.

We studied the accumulation of heavy metals (Zn, Cd, Ni and Pb) in muscle tissue of Whiteleg shrimp (Litopenaeus vannamei) sampled from shrimp farms in the Sistan Baluchistan, Iran. Sampling were conducted in April to June 2018 at three-time points of 35, 65 and 95 days after stocking in ponds randomly with three replications from two farms and two pools. After biometry, muscle tissue was isolated and the amount of metal accumulation was measured using flame atomic absorption apparatus. Results showed that the mean length (cm) and weight (g) were 6.15±0.65 and 4±0.8 in 35 days after stocking,10.63±0.73 and 9.61±1.63 in 65 days after stocking and 12.33 ± 0.51 and 16.04±1.33 in 95 days after stocking. The results showed a significant difference between the concentrations of zinc, cadmium, nickel and lead in sampling pools (p<0.05).The results did not show a significant difference between the pools at each time interval (p>0.05).The trend in heavy metal accumulation muscle tissue was increasing after stocking. The mean concentration of metals was 11.52±0.42 for copper, 82.95±6.65 for zinc, 3.54±0.47 for cadmium, 2.18±0.31 for nickel and 1.85±0.19 for lead (μg/g dry weight).  With the exception of nickel, which was  near the WHO standard, other metals were lower than the standard values reported by International Food and Drug Administration (FDA) and the World Health Organization (WHO).

Pacific white shrimp (Litopenaeus vannamei) is an important economic species in aquaculture industry. Effect of cinnamon, star anise, ginger, fennel, nutmeg, licorice, dried apple peel and spice mix on lipid and protein oxidation of shrimp mince during refrigerated storage at 4 ºC for 8 days was evaluated. Total phenolic contents in all spices were between 669.7 and 1538.4 mg gallic acid equivalents /g dry matter. Licorice, cinnamon and spice mix at 100 µg gallic acid equivalent/ g mince led to the best odor and color in samples after 8 days of storage (P < 0.05). These minces showed lower protein carbonyls and higher total sulfhydryl groups with the coincidental lower lipid oxidation (P < 0.05). In minces incorporated with nutmeg or fennel extracts, rancid odor was noticeable with higher formation of protein carbonyls and TBARS. Ginger-treated mince showed the lowest bacterial count (4.16 log CFU/g) at day 8. Spice mix extract showed antioxidant activity in scavenging free radicals (DPPH, ABTS, and hydroxyl) with IC50 of 15.1, 92.1 and 72.4 ppm, respectively. Results indicated the effect of spice mix in oxidative stability of vannamei shrimp mince during 8 days of refrigerated storage.

The aim of this study was to evaluate the effects of biofloc (with addition of spoilage date palm extract (SDE) and molasses as sugar sources) on bacterial load of water, growth performance and intestine of Litopenaeus vannamei using diets containing different protein levels. Four biofloc treatments were designated including the biofloc treatment with SDE + a diet containing 25% protein (P25), biofloc treatment with molasses + a diet containing 25% protein (M25), biofloc treatment with SDE + a diet containing 15% protein (P15), biofloc treatment with molasses + a diet containing 15% protein (M15) and the control treatment with a diet containing 38% protein (Control). All treatments were conducted in triplicates. A 35-day study was conducted on 35 juvenile shrimp (with average weight of 5.37±0.33 g) which randomly stocked in fifteen tanks (each 300 L) at a stocking density of 175 shrimp m−3. The highest amounts of growth parameters (weight gain, Feed Conversion Ratio (FCR), growth rate and survival) were observed in P25 treatment and the lowest amounts of growth parameters were observed in the control (P<0.05). Moreover, the highest percentages of body weight index, feed efficiency and specific growth rate were observed in P25 and the lowest percentages of those were observed in M15 treatment (P<0.05). Results showed that the number of total heterotrophic bacteria was increased during the study and the numbers of total heterotrophic bacteria in all biofloc treatments were higher than that of the control. The highest and the lowest numbers of fungi, vibrio and bacillus were found in P25 treatment and the control treatment, respectively. The length of the epithelial cells of the intestine was increased in all biofloc treatments as compared to the control but this difference was significant in the first abdominal segment, only. The result demonstrated that the effects of SDE were better than molasses, which could be due to the presence of useful compounds such as the growth and immunity promoters in it.

The effects of Pediiococcus acidilactici and Lactococcus lactis was evaluated on survival rate and some immunological parameters of L. vannamei during three months of cultivations. Treatments included control group, Pediococcus and Lactococcus treatments and probotic treatmentsfed at 1×109 cfu g-1. The results indicated that probiotics increased the survival rate (P

Litopenaeus vannamei (Boone, 1931) post-larvae 12 were obtained from Bushehr province and reared at the Caspian Sea Ecological Research Iinstitute (Mazandaran, Iran) in summer 2012 using brackish water of the Caspian Sea. Prior to start of the experiment, post-larvae were gradually adapted to brackish water. The shrimp was stocked in a 1000 m2 earthen pond with a stocking density of 31 individual/m2. The earthen pond was in quarantine without discharge valve. During the rearing period, there was no water exchange. The shrimp was reared for 85 days. The average daily growth, final mean weight, feed conversion ratio and final yield were 0.31±0.04 g, 21.11±0.71 g, 0.79 and 531 kg, respectively. The results showed that L. vannamei can growth well in brackish water of Caspian Sea (salinity of 11.1±0.7 ppt and temperature of 28.67±0.72 °C) in Mazandaran province from July to September.

The effect of simultaneous application of probiotic and digestive enzyme on the intestinal digestive activity of the whiteleg shrimp, Litopenaeus vannamei, was evaluated. For this purpose, the juvenile shrimps were fed for 30 days with a dietary probio-enzyme (containing a combination of six exogenous enzymes and four probiotic bacterial strains) at four concentrations of 0, 0.25, 0.5, and 1 g kg-1 feed. Shrimps (5.04±0.39 g ind-1) were randomly distributed in 12 aquaria (4 treatments × 3 replications); each aquarium contained 15 individual shrimps. Results indicated significantly (p≤0.05) higher growth performance, amylase and lipase activity at 0.5 g kg-1 treatment as compared to other treatments. Protease activity was, however, significantly (p≤ 0.05) higher at 1.0 g kg-1treatment as compared to other groups. Results also indicated that increase in the concentration of probiotic and enzymes supplementation was not associated with increase in all the digestive enzyme activity. In other words, probiotics and enzymes onlywithin specific range can have positive effect on growth performance and digestive enzyme activity of L. vannamei, above or below.

The monitoring of the Management of vannamei shrimp Farms in the Gomishan shrimp Site in the best way and to its development. The objectives of the project were the calculation of growth indices, Food Conversion Ratio.The Final production of vannamei, benefit-cost or gross benefit of each Farm.This study carried out in in 1391(2012).Data collection done through questionaries personally from Farm executive managers during culture period with the arrangment of shrimp department of the Golestan fisheries organization. Results indicated that, the average production of Khazar-Abzi Farm Semi-intensive system was 1389.3 kg/ha; The average weight(gr), FCR and Survival Rate(%) were 15.3, 0.87 and 92.5 respectively. The cost of Farming and the benefit of each kilograms of shrimp produced without the calculation of the depreciation of capital assets and construactions were 34525 and 55475 Rials respectively. The average production of Farm number 13(Persian kian pad) with intensive system was 3903 kg/ha. The average weight(gr), F.C.R and Survival Ratio(%) were 14.6, 1.25 and 74.3 respectively. The Farming cost and the benefit of each kg cultured shrimp were 50402and 39598 Rials respectively.

This study investigates the effects of garlic extract on salinity and PH stress resistance of white leg shrimp post larvae (0.1±0.01 g). The experiment was carried out on the basis of completely random model with 5 dietary treatments which include 0 (control treatment), 1cc (treatment 1), 2cc (treatment 2), 4cc (treatment 3) and 8cc (treatment 4) per 100g food in triplicate. 1500 shrimps were randomly stocked in 15 tanks (100 shrimps in each tank). Shrimps were fed 4 times a day for 7 weeks. At the end of this period, growth and nutritional indices were measured. Salinity and PH stress experiment was done. The results showed that use of 4cc and 8cc of garlic extract for each 100 gr in White leg shrimp’s post larvae improve growth indices of shrimps with regard to control treatment. Results showed that mortality started in 70 and 80ppt salinity, treatment 2 showed significant difference with control, and treatments 3 and 4 had significant difference with control and treatments 1 and 2. In 90ppt salinity treatments 2, 3 and 4 showed significant difference with control treatment. In PH stress, at pH 9 and 10 significant difference was not observed among treatments but in PH 10.5 significant difference showed between treatment 2 and control and treatments 3 and 4 with control and treatment 1. The results show that the economy could be due to diets containing garlic extract 4cc making diets for shrimp larvae posts be considered.

The effect of an imported and an indigenous probiotics on growth, feeding parameters and survival of whiteleg shrimp (Litopenaeus vannamei) postlarvae (50±6.54 mg) was investigated during 60 days feeding trial. The shrimp was fed three times daily at 7 percent of biomass with three feeds supplemented with probiotics (an imported and an indigenous ones, and an equal amount of both (, plus a blank feed as control. Probiotic supplemented feed brought about a higher final weight and final length, specific growth rate, better feed conversion ratio and a higher resistance to stress (p

The effects of diets containing enriched Artemia with highly unsaturated fatty acids and different amounts of vitamin C on the growth factors and survival rate of Litopenaeus vannamei larvae was studied. We used four different groups (three treatments and one control) with 3 replicate for each treatment during 15 days. All post larvae were randomly selected and fed with four diets containing normal Artemia (control treatment), Artemia enriched with cod liver oil (treatment 1), Artemia enriched with cod liver oil and 10 percent of vitamin C (treatment 2) and Artemia enriched with cod liver oil and 20 percent of vitamin C (treatment 3). Farming of shrimp larvae from PL1 to PL15 was completed in 300 liters tanks each containing around 150 liters of water. At the end of the experiment, the growth factors and survival rate of stage PL15 in treatments 1, 2 and 3 improved in comparison with control treatment. The survival rate at PL15 in treatments 2 and 3 showed a significant difference from control due to the synergistic properties of unsaturated fatty acid and vitamin C. No significant difference was found for survival rate between treatment 1 and the control treatment in PL15 stage. Also, no significant difference was seen for growth rate between treatments 2 and 3 in PL15. The highest growth factors and survival rate among different treatments in stage PL15 was observed in treatment 3 (diets containing Artemia enriched with cod liver oil and 20 percent vitamin C) and the lowest was associated with control treatment, diets containing un-enriched Artemia.

This study was conducted in the Shrimp Reseach Center of Bushehr in winter 2005. We treated reared White Leg Shrimp (Litopenaeus vannamei Boone 1931) with five diets containing 20%, 25% ,30%, 35% and 40% protein levels and three salinity levels 15-17ppt, 27-30ppt, and 40-45ppt. We focused on growth, survival, food conversion ratio, hemolymph osmolality, hemolymph protein and corpse protein content. We applied 15 treatments each with three replicates in 45 tanks with 300 liter capacity. Shrimps average weight was about 2 grams at the start and reared after 60 days of culture. Shrimp biomass growth in 15-17 salinity was higher than other salinities showing statistically significant difference with those grew in 40-45ppt salinity (P>0.05). No statistically significant difference was found between growth of the shrimp in 15-17ppt and in 27-30ppt water. Survival in 15-17ppt salinity was 97.03, lower than other salinities, while those in 24-30ppt and 40-45ppt salinities had the highest survival 99.33%. The highest growth was seen in diet number 5 with 40 percent protein content which showed a meaningful difference to that of other diets (P<0.05). No statistically significant differences were found between diets in terms of production costs and survival rates.

The LC50 of Virkon-S which is an antimicrobial agent for the shrimp Litopenaeus vannamei juveniles with mean body weight 2.39g was determined. The study was conducted in Iran Shrimp Research Centre in Bushehr City, south Iran in 2006. The LC50 96h value of Virkon-S was 43.23 mg/lit corresponding to 43.23ppm. All of important physicochemical parameters of sea water were monitored and maintained at a constant value so that temperature was 28-33 degrees centigrade, pH was between 7.2-7.9, dissolved oxygen was £4.8 and salinity was around 37ppt. Five treatments and three replicates were run for each treatment. The software used was LC50ModelSystem version 1.0 that let the estimation of LC50 values by Spearman-Karber rule with (P£0.05).